From 04c0b0e6eb5798240cbaff49479be7892eb34453 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 8 Apr 2019 13:00:09 -0400
Subject: [PATCH 01/40] Add 'pip cache' command.

---
 src/pip/_internal/commands/__init__.py |   4 +
 src/pip/_internal/commands/cache.py    | 106 +++++++++++++++++++++++++
 src/pip/_internal/utils/filesystem.py  |  14 +++-
 tests/functional/test_cache.py         |  68 ++++++++++++++++
 4 files changed, 191 insertions(+), 1 deletion(-)
 create mode 100644 src/pip/_internal/commands/cache.py
 create mode 100644 tests/functional/test_cache.py

diff --git a/src/pip/_internal/commands/__init__.py b/src/pip/_internal/commands/__init__.py
index 2a311f8fc89..8507b6ef9f0 100644
--- a/src/pip/_internal/commands/__init__.py
+++ b/src/pip/_internal/commands/__init__.py
@@ -64,6 +64,10 @@
         'pip._internal.commands.search', 'SearchCommand',
         'Search PyPI for packages.',
     )),
+    ('cache', CommandInfo(
+        'pip._internal.commands.cache', 'CacheCommand',
+        "Inspect and manage pip's caches.",
+    )),
     ('wheel', CommandInfo(
         'pip._internal.commands.wheel', 'WheelCommand',
         'Build wheels from your requirements.',
diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
new file mode 100644
index 00000000000..0fe3352d22f
--- /dev/null
+++ b/src/pip/_internal/commands/cache.py
@@ -0,0 +1,106 @@
+from __future__ import absolute_import
+
+import logging
+import os
+import textwrap
+
+from pip._internal.cli.base_command import Command
+from pip._internal.exceptions import CommandError
+from pip._internal.utils.filesystem import find_files
+
+logger = logging.getLogger(__name__)
+
+
+class CacheCommand(Command):
+    """
+    Inspect and manage pip's caches.
+
+    Subcommands:
+        info:
+            Show information about the caches.
+        list [name]:
+            List filenames of packages stored in the cache.
+        remove <pattern>:
+            Remove one or more package from the cache.
+            `pattern` can be a glob expression or a package name.
+        purge:
+            Remove all items from the cache.
+    """
+    actions = ['info', 'list', 'remove', 'purge']
+    name = 'cache'
+    usage = """
+      %prog <command>"""
+    summary = "View and manage which packages are available in pip's caches."
+
+    def __init__(self, *args, **kw):
+        super(CacheCommand, self).__init__(*args, **kw)
+
+    def run(self, options, args):
+        if not args:
+            raise CommandError('Please provide a subcommand.')
+
+        if args[0] not in self.actions:
+            raise CommandError('Invalid subcommand: %s' % args[0])
+
+        self.wheel_dir = os.path.join(options.cache_dir, 'wheels')
+
+        method = getattr(self, 'action_%s' % args[0])
+        return method(options, args[1:])
+
+    def action_info(self, options, args):
+        format_args = (options.cache_dir, len(self.find_wheels('*.whl')))
+        result = textwrap.dedent(
+            """\
+            Cache info:
+              Location: %s
+              Packages: %s""" % format_args
+        )
+        logger.info(result)
+
+    def action_list(self, options, args):
+        if args and args[0]:
+            pattern = args[0]
+        else:
+            pattern = '*'
+
+        files = self.find_wheels(pattern)
+        wheels = map(self._wheel_info, files)
+        wheels = sorted(set(wheels))
+
+        if not wheels:
+            logger.info('Nothing is currently cached.')
+            return
+
+        result = 'Current cache contents:\n'
+        for wheel in wheels:
+            result += ' - %s\n' % wheel
+        logger.info(result.strip())
+
+    def action_remove(self, options, args):
+        if not args:
+            raise CommandError('Please provide a pattern')
+
+        files = self.find_wheels(args[0])
+        if not files:
+            raise CommandError('No matching packages')
+
+        wheels = map(self._wheel_info, files)
+        result = 'Removing cached wheels for:\n'
+        for wheel in wheels:
+            result += '- %s\n' % wheel
+
+        for filename in files:
+            os.unlink(filename)
+            logger.debug('Removed %s', filename)
+        logger.info('Removed %s files', len(files))
+
+    def action_purge(self, options, args):
+        return self.action_remove(options, '*')
+
+    def _wheel_info(self, path):
+        filename = os.path.splitext(os.path.basename(path))[0]
+        name, version = filename.split('-')[0:2]
+        return '%s-%s' % (name, version)
+
+    def find_wheels(self, pattern):
+        return find_files(self.wheel_dir, pattern + '-*.whl')
diff --git a/src/pip/_internal/utils/filesystem.py b/src/pip/_internal/utils/filesystem.py
index 36578fb6244..2772e0880e4 100644
--- a/src/pip/_internal/utils/filesystem.py
+++ b/src/pip/_internal/utils/filesystem.py
@@ -1,4 +1,5 @@
 import errno
+import fnmatch
 import os
 import os.path
 import random
@@ -17,7 +18,7 @@
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING, cast
 
 if MYPY_CHECK_RUNNING:
-    from typing import Any, BinaryIO, Iterator
+    from typing import Any, BinaryIO, Iterator, List
 
     class NamedTemporaryFileResult(BinaryIO):
         @property
@@ -176,3 +177,14 @@ def _test_writable_dir_win(path):
     raise EnvironmentError(
         'Unexpected condition testing for writable directory'
     )
+
+
+def find_files(path, pattern):
+    # type: (str, str) -> List[str]
+    """Returns a list of absolute paths of files beneath path, recursively,
+    with filenames which match the UNIX-style shell glob pattern."""
+    result = []  # type: List[str]
+    for root, dirs, files in os.walk(path):
+        matches = fnmatch.filter(files, pattern)
+        result.extend(os.path.join(root, f) for f in matches)
+    return result
diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
new file mode 100644
index 00000000000..34cd95b836d
--- /dev/null
+++ b/tests/functional/test_cache.py
@@ -0,0 +1,68 @@
+import os
+import shutil
+
+from pip._internal.utils import appdirs
+
+
+def _cache_dir(script):
+    results = script.run(
+        'python', '-c',
+        'from pip._internal.locations import USER_CACHE_DIR;'
+        'print(USER_CACHE_DIR)'
+    )
+    return str(results.stdout).strip()
+
+
+def test_cache_info(script, monkeypatch):
+    result = script.pip('cache', 'info')
+    cache_dir = _cache_dir(script)
+
+    assert 'Location: %s' % cache_dir in result.stdout
+    assert 'Packages: ' in result.stdout
+
+
+def test_cache_list(script, monkeypatch):
+    cache_dir = _cache_dir(script)
+    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
+    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+    os.makedirs(destination)
+    with open(os.path.join(destination, 'yyy-1.2.3.whl'), 'w'):
+        pass
+    with open(os.path.join(destination, 'zzz-4.5.6.whl'), 'w'):
+        pass
+    result = script.pip('cache', 'list')
+    assert 'yyy-1.2.3' in result.stdout
+    assert 'zzz-4.5.6' in result.stdout
+    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
+
+
+def test_cache_list_with_pattern(script, monkeypatch):
+    cache_dir = _cache_dir(script)
+    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
+    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+    os.makedirs(destination)
+    with open(os.path.join(destination, 'yyy-1.2.3.whl'), 'w'):
+        pass
+    with open(os.path.join(destination, 'zzz-4.5.6.whl'), 'w'):
+        pass
+    result = script.pip('cache', 'list', 'zzz')
+    assert 'yyy-1.2.3' not in result.stdout
+    assert 'zzz-4.5.6' in result.stdout
+    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
+
+
+def test_cache_remove(script, monkeypatch):
+    cache_dir = _cache_dir(script)
+    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
+    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+    os.makedirs(destination)
+    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3.whl'), 'w'):
+        pass
+    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6.whl'), 'w'):
+        pass
+
+    script.pip('cache', 'remove', expect_error=True)
+    result = script.pip('cache', 'remove', 'zzz', '--verbose')
+    assert 'yyy-1.2.3' not in result.stdout
+    assert 'zzz-4.5.6' in result.stdout
+    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))

From b0e7b66326b22984c62965c861190da88c1a79db Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 7 Oct 2019 23:03:03 -0400
Subject: [PATCH 02/40] [commands/cache] Refactor + fix linting failures.

---
 src/pip/_internal/commands/cache.py | 112 ++++++++++++++++++----------
 tests/functional/test_cache.py      |   2 -
 2 files changed, 72 insertions(+), 42 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 0fe3352d22f..7d5fb85ca64 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -5,50 +5,76 @@
 import textwrap
 
 from pip._internal.cli.base_command import Command
-from pip._internal.exceptions import CommandError
+from pip._internal.cli.status_codes import ERROR, SUCCESS
+from pip._internal.exceptions import CommandError, PipError
 from pip._internal.utils.filesystem import find_files
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from optparse import Values
+    from typing import Any, List
+
 
 logger = logging.getLogger(__name__)
 
 
 class CacheCommand(Command):
-    """
-    Inspect and manage pip's caches.
-
-    Subcommands:
-        info:
-            Show information about the caches.
-        list [name]:
-            List filenames of packages stored in the cache.
-        remove <pattern>:
-            Remove one or more package from the cache.
-            `pattern` can be a glob expression or a package name.
-        purge:
-            Remove all items from the cache.
+    """Inspect and manage pip's caches.
+
+        Subcommands:
+
+        info: Show information about the caches.
+        list: List filenames of packages stored in the cache.
+        remove: Remove one or more package from the cache.
+        purge: Remove all items from the cache.
+
+        <pattern> can be a glob expression or a package name.
     """
     actions = ['info', 'list', 'remove', 'purge']
-    name = 'cache'
     usage = """
-      %prog <command>"""
-    summary = "View and manage which packages are available in pip's caches."
+        %prog info
+        %prog list [name]
+        %prog remove <pattern>
+        %prog purge
+    """
 
     def __init__(self, *args, **kw):
+        # type: (*Any, **Any) -> None
         super(CacheCommand, self).__init__(*args, **kw)
 
     def run(self, options, args):
-        if not args:
-            raise CommandError('Please provide a subcommand.')
-
-        if args[0] not in self.actions:
-            raise CommandError('Invalid subcommand: %s' % args[0])
-
-        self.wheel_dir = os.path.join(options.cache_dir, 'wheels')
-
-        method = getattr(self, 'action_%s' % args[0])
-        return method(options, args[1:])
-
-    def action_info(self, options, args):
-        format_args = (options.cache_dir, len(self.find_wheels('*.whl')))
+        # type: (Values, List[Any]) -> int
+        handlers = {
+            "info": self.get_cache_info,
+            "list": self.list_cache_items,
+            "remove": self.remove_cache_items,
+            "purge": self.purge_cache,
+        }
+
+        # Determine action
+        if not args or args[0] not in handlers:
+            logger.error("Need an action ({}) to perform.".format(
+                ", ".join(sorted(handlers)))
+            )
+            return ERROR
+
+        action = args[0]
+
+        # Error handling happens here, not in the action-handlers.
+        try:
+            handlers[action](options, args[1:])
+        except PipError as e:
+            logger.error(e.args[0])
+            return ERROR
+
+        return SUCCESS
+
+    def get_cache_info(self, options, args):
+        # type: (Values, List[Any]) -> None
+        format_args = (
+            options.cache_dir,
+            len(self._find_wheels(options, '*.whl'))
+        )
         result = textwrap.dedent(
             """\
             Cache info:
@@ -57,15 +83,16 @@ def action_info(self, options, args):
         )
         logger.info(result)
 
-    def action_list(self, options, args):
+    def list_cache_items(self, options, args):
+        # type: (Values, List[Any]) -> None
         if args and args[0]:
             pattern = args[0]
         else:
             pattern = '*'
 
-        files = self.find_wheels(pattern)
-        wheels = map(self._wheel_info, files)
-        wheels = sorted(set(wheels))
+        files = self._find_wheels(options, pattern)
+        wheels_ = map(self._wheel_info, files)
+        wheels = sorted(set(wheels_))
 
         if not wheels:
             logger.info('Nothing is currently cached.')
@@ -76,11 +103,12 @@ def action_list(self, options, args):
             result += ' - %s\n' % wheel
         logger.info(result.strip())
 
-    def action_remove(self, options, args):
+    def remove_cache_items(self, options, args):
+        # type: (Values, List[Any]) -> None
         if not args:
             raise CommandError('Please provide a pattern')
 
-        files = self.find_wheels(args[0])
+        files = self._find_wheels(options, args[0])
         if not files:
             raise CommandError('No matching packages')
 
@@ -94,13 +122,17 @@ def action_remove(self, options, args):
             logger.debug('Removed %s', filename)
         logger.info('Removed %s files', len(files))
 
-    def action_purge(self, options, args):
-        return self.action_remove(options, '*')
+    def purge_cache(self, options, args):
+        # type: (Values, List[Any]) -> None
+        return self.remove_cache_items(options, ['*'])
 
     def _wheel_info(self, path):
+        # type: (str) -> str
         filename = os.path.splitext(os.path.basename(path))[0]
         name, version = filename.split('-')[0:2]
         return '%s-%s' % (name, version)
 
-    def find_wheels(self, pattern):
-        return find_files(self.wheel_dir, pattern + '-*.whl')
+    def _find_wheels(self, options, pattern):
+        # type: (Values, str) -> List[str]
+        wheel_dir = os.path.join(options.cache_dir, 'wheels')
+        return find_files(wheel_dir, pattern + '-*.whl')
diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 34cd95b836d..05fcb4505d1 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -1,8 +1,6 @@
 import os
 import shutil
 
-from pip._internal.utils import appdirs
-
 
 def _cache_dir(script):
     results = script.run(

From b9b29b8c10a18843dfbb0c23a33c073b8de603c2 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 7 Oct 2019 23:31:01 -0400
Subject: [PATCH 03/40] [commands/cache] fix 'pip cache info'; don't hide
 python/abi/platform tags.

---
 src/pip/_internal/commands/cache.py | 11 ++---------
 tests/functional/test_cache.py      |  3 +++
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 7d5fb85ca64..ee669016728 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -73,7 +73,7 @@ def get_cache_info(self, options, args):
         # type: (Values, List[Any]) -> None
         format_args = (
             options.cache_dir,
-            len(self._find_wheels(options, '*.whl'))
+            len(self._find_wheels(options, '*'))
         )
         result = textwrap.dedent(
             """\
@@ -112,11 +112,6 @@ def remove_cache_items(self, options, args):
         if not files:
             raise CommandError('No matching packages')
 
-        wheels = map(self._wheel_info, files)
-        result = 'Removing cached wheels for:\n'
-        for wheel in wheels:
-            result += '- %s\n' % wheel
-
         for filename in files:
             os.unlink(filename)
             logger.debug('Removed %s', filename)
@@ -128,9 +123,7 @@ def purge_cache(self, options, args):
 
     def _wheel_info(self, path):
         # type: (str) -> str
-        filename = os.path.splitext(os.path.basename(path))[0]
-        name, version = filename.split('-')[0:2]
-        return '%s-%s' % (name, version)
+        return os.path.basename(path)
 
     def _find_wheels(self, options, pattern):
         # type: (Values, str) -> List[str]
diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 05fcb4505d1..5c97cfe1903 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -16,6 +16,9 @@ def test_cache_info(script, monkeypatch):
     cache_dir = _cache_dir(script)
 
     assert 'Location: %s' % cache_dir in result.stdout
+    # TODO(@duckinator): This should probably test that the number of
+    #   packages is actually correct, but I'm not sure how to do that
+    #   without pretty much re-implementing the entire cache info command.
     assert 'Packages: ' in result.stdout
 
 

From c59ced69422cc4831a2c84662bc0c1d6dc7f6ae5 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 7 Oct 2019 23:50:47 -0400
Subject: [PATCH 04/40] [commands/cache] More refactoring of cache command

---
 src/pip/_internal/commands/cache.py | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index ee669016728..7ab7e6c88f4 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -30,7 +30,7 @@ class CacheCommand(Command):
 
         <pattern> can be a glob expression or a package name.
     """
-    actions = ['info', 'list', 'remove', 'purge']
+
     usage = """
         %prog info
         %prog list [name]
@@ -71,17 +71,15 @@ def run(self, options, args):
 
     def get_cache_info(self, options, args):
         # type: (Values, List[Any]) -> None
-        format_args = (
-            options.cache_dir,
-            len(self._find_wheels(options, '*'))
-        )
-        result = textwrap.dedent(
-            """\
+        num_packages = len(self._find_wheels(options, '*'))
+
+        results = textwrap.dedent("""\
             Cache info:
               Location: %s
-              Packages: %s""" % format_args
+              Packages: %s""" % (options.cache_dir, num_packages)
         )
-        logger.info(result)
+
+        logger.info(results)
 
     def list_cache_items(self, options, args):
         # type: (Values, List[Any]) -> None
@@ -91,8 +89,7 @@ def list_cache_items(self, options, args):
             pattern = '*'
 
         files = self._find_wheels(options, pattern)
-        wheels_ = map(self._wheel_info, files)
-        wheels = sorted(set(wheels_))
+        wheels = sorted(set(map(lambda f: os.path.basename(f), files)))
 
         if not wheels:
             logger.info('Nothing is currently cached.')
@@ -121,10 +118,6 @@ def purge_cache(self, options, args):
         # type: (Values, List[Any]) -> None
         return self.remove_cache_items(options, ['*'])
 
-    def _wheel_info(self, path):
-        # type: (str) -> str
-        return os.path.basename(path)
-
     def _find_wheels(self, options, pattern):
         # type: (Values, str) -> List[str]
         wheel_dir = os.path.join(options.cache_dir, 'wheels')

From 8ae71adbea407f4cca5baba31e9e6687571cc8f4 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 7 Oct 2019 23:59:30 -0400
Subject: [PATCH 05/40] [commands/cache] Add docs for 'pip cache' command.

---
 docs/man/commands/cache.rst         | 20 ++++++++++++++++++++
 src/pip/_internal/commands/cache.py | 15 ++++++++++-----
 2 files changed, 30 insertions(+), 5 deletions(-)
 create mode 100644 docs/man/commands/cache.rst

diff --git a/docs/man/commands/cache.rst b/docs/man/commands/cache.rst
new file mode 100644
index 00000000000..b0241c8135e
--- /dev/null
+++ b/docs/man/commands/cache.rst
@@ -0,0 +1,20 @@
+:orphan:
+
+==========
+pip-cache
+==========
+
+Description
+***********
+
+.. pip-command-description:: cache
+
+Usage
+*****
+
+.. pip-command-usage:: cache
+
+Options
+*******
+
+.. pip-command-options:: cache
diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 7ab7e6c88f4..8dadc6a0e33 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -19,14 +19,19 @@
 
 
 class CacheCommand(Command):
-    """Inspect and manage pip's caches.
+    """
+        Inspect and manage pip's caches.
 
         Subcommands:
 
-        info: Show information about the caches.
-        list: List filenames of packages stored in the cache.
-        remove: Remove one or more package from the cache.
-        purge: Remove all items from the cache.
+        info:
+            Show information about the caches.
+        list:
+            List filenames of packages stored in the cache.
+        remove:
+            Remove one or more package from the cache.
+        purge:
+            Remove all items from the cache.
 
         <pattern> can be a glob expression or a package name.
     """

From d57dcd934e11e069bf4bd37e8dff8d777b452217 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 8 Oct 2019 00:00:24 -0400
Subject: [PATCH 06/40] [commands/cache] Add news file for cache command.

---
 news/6391.feature | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 news/6391.feature

diff --git a/news/6391.feature b/news/6391.feature
new file mode 100644
index 00000000000..73d6dffca8a
--- /dev/null
+++ b/news/6391.feature
@@ -0,0 +1 @@
+Add ``pip cache`` command for inspecting/managing pip's cache.

From 50604be6c4908f481e4ca1ea17cfaa9ec06ca417 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Wed, 9 Oct 2019 19:58:23 -0400
Subject: [PATCH 07/40] [commands/cache] Raise errors if wrong number of args.

Also add tests for purge_cache, since I apparently forgot those before.
---
 src/pip/_internal/commands/cache.py | 11 ++++++++-
 tests/functional/test_cache.py      | 36 +++++++++++++++++++++++++++--
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 8dadc6a0e33..8afe5be53d5 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -88,7 +88,10 @@ def get_cache_info(self, options, args):
 
     def list_cache_items(self, options, args):
         # type: (Values, List[Any]) -> None
-        if args and args[0]:
+        if len(args) > 1:
+            raise CommandError('Too many arguments')
+
+        if args:
             pattern = args[0]
         else:
             pattern = '*'
@@ -107,6 +110,9 @@ def list_cache_items(self, options, args):
 
     def remove_cache_items(self, options, args):
         # type: (Values, List[Any]) -> None
+        if len(args) > 1:
+            raise CommandError('Too many arguments')
+
         if not args:
             raise CommandError('Please provide a pattern')
 
@@ -121,6 +127,9 @@ def remove_cache_items(self, options, args):
 
     def purge_cache(self, options, args):
         # type: (Values, List[Any]) -> None
+        if args:
+            raise CommandError('Too many arguments')
+
         return self.remove_cache_items(options, ['*'])
 
     def _find_wheels(self, options, pattern):
diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 5c97cfe1903..6388155df2a 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -3,12 +3,12 @@
 
 
 def _cache_dir(script):
-    results = script.run(
+    result = script.run(
         'python', '-c',
         'from pip._internal.locations import USER_CACHE_DIR;'
         'print(USER_CACHE_DIR)'
     )
-    return str(results.stdout).strip()
+    return result.stdout.strip()
 
 
 def test_cache_info(script, monkeypatch):
@@ -37,6 +37,11 @@ def test_cache_list(script, monkeypatch):
     shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
 
 
+def test_cache_list_too_many_args(script, monkeypatch):
+    script.pip('cache', 'list', 'aaa', 'bbb',
+               expect_error=True)
+
+
 def test_cache_list_with_pattern(script, monkeypatch):
     cache_dir = _cache_dir(script)
     wheel_cache_dir = os.path.join(cache_dir, 'wheels')
@@ -67,3 +72,30 @@ def test_cache_remove(script, monkeypatch):
     assert 'yyy-1.2.3' not in result.stdout
     assert 'zzz-4.5.6' in result.stdout
     shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
+
+
+def test_cache_remove_too_many_args(script, monkeypatch):
+    result = script.pip('cache', 'remove', 'aaa', 'bbb',
+                        expect_error=True)
+
+
+def test_cache_purge(script, monkeypatch):
+    cache_dir = _cache_dir(script)
+    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
+    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+    os.makedirs(destination)
+    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3.whl'), 'w'):
+        pass
+    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6.whl'), 'w'):
+        pass
+
+    result = script.pip('cache', 'purge', 'aaa', '--verbose',
+                        expect_error=True)
+    assert 'yyy-1.2.3' not in result.stdout
+    assert 'zzz-4.5.6' not in result.stdout
+
+    result = script.pip('cache', 'purge', '--verbose')
+    assert 'yyy-1.2.3' in result.stdout
+    assert 'zzz-4.5.6' in result.stdout
+
+    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))

From 9563dfb526db14b1c9a00c66a25e1a7ec4d64e78 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Wed, 9 Oct 2019 20:00:34 -0400
Subject: [PATCH 08/40] [commands/cache] Refactor get_cache_info().

---
 src/pip/_internal/commands/cache.py | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 8afe5be53d5..8e6f12f4c94 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -78,13 +78,16 @@ def get_cache_info(self, options, args):
         # type: (Values, List[Any]) -> None
         num_packages = len(self._find_wheels(options, '*'))
 
-        results = textwrap.dedent("""\
+        message = textwrap.dedent("""
             Cache info:
-              Location: %s
-              Packages: %s""" % (options.cache_dir, num_packages)
-        )
-
-        logger.info(results)
+              Location: {location}
+              Packages: {package_count}
+        """).format(
+            location=options.cache_dir,
+            package_count=num_packages,
+        ).strip()
+
+        logger.info(message)
 
     def list_cache_items(self, options, args):
         # type: (Values, List[Any]) -> None

From 6fb1ee7a3d9c19995262f1961c7fb39fd459396e Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 10 Oct 2019 04:30:08 -0400
Subject: [PATCH 09/40] [commands/cache] fix linting error.

---
 tests/functional/test_cache.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 6388155df2a..745a6e2a772 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -75,8 +75,8 @@ def test_cache_remove(script, monkeypatch):
 
 
 def test_cache_remove_too_many_args(script, monkeypatch):
-    result = script.pip('cache', 'remove', 'aaa', 'bbb',
-                        expect_error=True)
+    script.pip('cache', 'remove', 'aaa', 'bbb',
+               expect_error=True)
 
 
 def test_cache_purge(script, monkeypatch):

From c838a6717859cfcf698ce49b0387dbd54d62a686 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 10 Oct 2019 05:27:51 -0400
Subject: [PATCH 10/40] [commands/cache] Change pattern suffix from -*.whl to
 *.whl.

---
 src/pip/_internal/commands/cache.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 8e6f12f4c94..daa9809ff89 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -138,4 +138,4 @@ def purge_cache(self, options, args):
     def _find_wheels(self, options, pattern):
         # type: (Values, str) -> List[str]
         wheel_dir = os.path.join(options.cache_dir, 'wheels')
-        return find_files(wheel_dir, pattern + '-*.whl')
+        return find_files(wheel_dir, pattern + '*.whl')

From 61dd0bc16c6d85567e5c29af92d65b9e58ec0388 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 10 Oct 2019 05:42:28 -0400
Subject: [PATCH 11/40] [commands/cache] Use location of wheel cache dir
 specifically.

---
 src/pip/_internal/commands/cache.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index daa9809ff89..09d7d455d9b 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -83,7 +83,7 @@ def get_cache_info(self, options, args):
               Location: {location}
               Packages: {package_count}
         """).format(
-            location=options.cache_dir,
+            location=self._wheels_cache_dir(options),
             package_count=num_packages,
         ).strip()
 
@@ -135,7 +135,10 @@ def purge_cache(self, options, args):
 
         return self.remove_cache_items(options, ['*'])
 
+    def _wheels_cache_dir(self, options):
+        return os.path.join(options.cache_dir, 'wheels')
+
     def _find_wheels(self, options, pattern):
         # type: (Values, str) -> List[str]
-        wheel_dir = os.path.join(options.cache_dir, 'wheels')
+        wheel_dir = self._wheels_cache_dir(options)
         return find_files(wheel_dir, pattern + '*.whl')

From 94a6593a5995373d3195367b6441316d03465d09 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 10 Oct 2019 05:46:57 -0400
Subject: [PATCH 12/40] [commands/cache] Add HTML docs for `pip cache`.

---
 docs/html/reference/index.rst     |  1 +
 docs/html/reference/pip_cache.rst | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 docs/html/reference/pip_cache.rst

diff --git a/docs/html/reference/index.rst b/docs/html/reference/index.rst
index f3312948193..d21b7a9801a 100644
--- a/docs/html/reference/index.rst
+++ b/docs/html/reference/index.rst
@@ -13,6 +13,7 @@ Reference Guide
    pip_list
    pip_show
    pip_search
+   pip_cache
    pip_check
    pip_config
    pip_wheel
diff --git a/docs/html/reference/pip_cache.rst b/docs/html/reference/pip_cache.rst
new file mode 100644
index 00000000000..d56d1b016ba
--- /dev/null
+++ b/docs/html/reference/pip_cache.rst
@@ -0,0 +1,22 @@
+
+.. _`pip cache`:
+
+pip cache
+------------
+
+.. contents::
+
+Usage
+*****
+
+.. pip-command-usage:: cache
+
+Description
+***********
+
+.. pip-command-description:: cache
+
+Options
+*******
+
+.. pip-command-options:: cache

From 61a0adcfe79043c17e905ae2e5d75b4ce8eaddd5 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 10 Oct 2019 05:51:06 -0400
Subject: [PATCH 13/40] [commands/cache] Add missing type annotation.

---
 src/pip/_internal/commands/cache.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 09d7d455d9b..72273265566 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -136,6 +136,7 @@ def purge_cache(self, options, args):
         return self.remove_cache_items(options, ['*'])
 
     def _wheels_cache_dir(self, options):
+        # type: (Values) -> str
         return os.path.join(options.cache_dir, 'wheels')
 
     def _find_wheels(self, options, pattern):

From 554133a90eb9611b3c828b5b65a5f91fc6fe0a01 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 6 Jan 2020 15:51:37 -0500
Subject: [PATCH 14/40] [commands/cache] Add file size information.

---
 src/pip/_internal/commands/cache.py   | 25 +++++++++-----
 src/pip/_internal/utils/filesystem.py | 50 ++++++++++++++++++++++++++-
 2 files changed, 65 insertions(+), 10 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 72273265566..80ea5c8f9a2 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -4,10 +4,10 @@
 import os
 import textwrap
 
+import pip._internal.utils.filesystem as filesystem
 from pip._internal.cli.base_command import Command
 from pip._internal.cli.status_codes import ERROR, SUCCESS
 from pip._internal.exceptions import CommandError, PipError
-from pip._internal.utils.filesystem import find_files
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 if MYPY_CHECK_RUNNING:
@@ -78,13 +78,18 @@ def get_cache_info(self, options, args):
         # type: (Values, List[Any]) -> None
         num_packages = len(self._find_wheels(options, '*'))
 
+        cache_location = self._wheels_cache_dir(options)
+        cache_size = filesystem.friendly_directory_size(cache_location)
+
         message = textwrap.dedent("""
             Cache info:
               Location: {location}
               Packages: {package_count}
+              Size:     {size}
         """).format(
-            location=self._wheels_cache_dir(options),
+            location=cache_location,
             package_count=num_packages,
+            size=cache_size,
         ).strip()
 
         logger.info(message)
@@ -100,16 +105,18 @@ def list_cache_items(self, options, args):
             pattern = '*'
 
         files = self._find_wheels(options, pattern)
-        wheels = sorted(set(map(lambda f: os.path.basename(f), files)))
 
-        if not wheels:
+        if not files:
             logger.info('Nothing is currently cached.')
             return
 
-        result = 'Current cache contents:\n'
-        for wheel in wheels:
-            result += ' - %s\n' % wheel
-        logger.info(result.strip())
+        results = []
+        for filename in files:
+            wheel = os.path.basename(filename)
+            size = filesystem.friendly_file_size(filename)
+            results.append(' - {} ({})'.format(wheel, size))
+        logger.info('Current cache contents:\n')
+        logger.info('\n'.join(sorted(results)))
 
     def remove_cache_items(self, options, args):
         # type: (Values, List[Any]) -> None
@@ -142,4 +149,4 @@ def _wheels_cache_dir(self, options):
     def _find_wheels(self, options, pattern):
         # type: (Values, str) -> List[str]
         wheel_dir = self._wheels_cache_dir(options)
-        return find_files(wheel_dir, pattern + '*.whl')
+        return filesystem.find_files(wheel_dir, pattern + '*.whl')
diff --git a/src/pip/_internal/utils/filesystem.py b/src/pip/_internal/utils/filesystem.py
index 2772e0880e4..7e369e4a843 100644
--- a/src/pip/_internal/utils/filesystem.py
+++ b/src/pip/_internal/utils/filesystem.py
@@ -18,7 +18,7 @@
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING, cast
 
 if MYPY_CHECK_RUNNING:
-    from typing import Any, BinaryIO, Iterator, List
+    from typing import Any, BinaryIO, Iterator, List, Union
 
     class NamedTemporaryFileResult(BinaryIO):
         @property
@@ -188,3 +188,51 @@ def find_files(path, pattern):
         matches = fnmatch.filter(files, pattern)
         result.extend(os.path.join(root, f) for f in matches)
     return result
+
+
+def _friendly_size(size):
+    # type: (Union[float, int]) -> str
+    suffix = 'B'
+    if size > 1000:
+        size /= 1000
+        suffix = 'KB'
+
+    if size > 1000:
+        size /= 1000
+        suffix = 'MB'
+
+    if size > 1000:
+        size /= 1000
+        suffix = 'GB'
+
+    size = round(size, 1)
+
+    return '{} {}'.format(size, suffix)
+
+
+def file_size(path):
+    # type: (str) -> Union[int, float]
+    # If it's a symlink, return 0.
+    if os.path.islink(path):
+        return 0
+    return os.path.getsize(path)
+
+
+def friendly_file_size(path):
+    # type: (str) -> str
+    return _friendly_size(file_size(path))
+
+
+def directory_size(path):
+    # type: (str) -> Union[int, float]
+    size = 0.0
+    for root, _dirs, files in os.walk(path):
+        for filename in files:
+            file_path = os.path.join(root, filename)
+            size += file_size(file_path)
+    return size
+
+
+def friendly_directory_size(path):
+    # type: (str) -> str
+    return _friendly_size(directory_size(path))

From 2d978309a2f439fe8b9cfe9624f6daeccb772005 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Mon, 13 Jan 2020 17:53:16 -0500
Subject: [PATCH 15/40] [commands/cache] Minor clean-up.

- Consistently use singular 'cache' (not plural 'caches').
- Remove unnecessary uses of the word 'currently'.
- Use 'file(s)' instead of 'files', to account for case of only one file.
- Use .format() when appropriate.
- Minor cleanup of `pip cache`-related files in docs/.
---
 docs/html/reference/pip_cache.rst      |  2 +-
 docs/man/commands/cache.rst            |  4 ++--
 src/pip/_internal/commands/__init__.py |  2 +-
 src/pip/_internal/commands/cache.py    | 10 +++++-----
 tests/functional/test_cache.py         |  2 +-
 5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/docs/html/reference/pip_cache.rst b/docs/html/reference/pip_cache.rst
index d56d1b016ba..8ad99f65cba 100644
--- a/docs/html/reference/pip_cache.rst
+++ b/docs/html/reference/pip_cache.rst
@@ -2,7 +2,7 @@
 .. _`pip cache`:
 
 pip cache
-------------
+---------
 
 .. contents::
 
diff --git a/docs/man/commands/cache.rst b/docs/man/commands/cache.rst
index b0241c8135e..8f8e197f922 100644
--- a/docs/man/commands/cache.rst
+++ b/docs/man/commands/cache.rst
@@ -1,8 +1,8 @@
 :orphan:
 
-==========
+=========
 pip-cache
-==========
+=========
 
 Description
 ***********
diff --git a/src/pip/_internal/commands/__init__.py b/src/pip/_internal/commands/__init__.py
index 8507b6ef9f0..48e288ab345 100644
--- a/src/pip/_internal/commands/__init__.py
+++ b/src/pip/_internal/commands/__init__.py
@@ -66,7 +66,7 @@
     )),
     ('cache', CommandInfo(
         'pip._internal.commands.cache', 'CacheCommand',
-        "Inspect and manage pip's caches.",
+        "Inspect and manage pip's cache.",
     )),
     ('wheel', CommandInfo(
         'pip._internal.commands.wheel', 'WheelCommand',
diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 80ea5c8f9a2..9a473aeefb9 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -20,12 +20,12 @@
 
 class CacheCommand(Command):
     """
-        Inspect and manage pip's caches.
+        Inspect and manage pip's cache.
 
         Subcommands:
 
         info:
-            Show information about the caches.
+            Show information about the cache.
         list:
             List filenames of packages stored in the cache.
         remove:
@@ -107,7 +107,7 @@ def list_cache_items(self, options, args):
         files = self._find_wheels(options, pattern)
 
         if not files:
-            logger.info('Nothing is currently cached.')
+            logger.info('Nothing cached.')
             return
 
         results = []
@@ -115,7 +115,7 @@ def list_cache_items(self, options, args):
             wheel = os.path.basename(filename)
             size = filesystem.friendly_file_size(filename)
             results.append(' - {} ({})'.format(wheel, size))
-        logger.info('Current cache contents:\n')
+        logger.info('Cache contents:\n')
         logger.info('\n'.join(sorted(results)))
 
     def remove_cache_items(self, options, args):
@@ -133,7 +133,7 @@ def remove_cache_items(self, options, args):
         for filename in files:
             os.unlink(filename)
             logger.debug('Removed %s', filename)
-        logger.info('Removed %s files', len(files))
+        logger.info('Removed %s file(s)', len(files))
 
     def purge_cache(self, options, args):
         # type: (Values, List[Any]) -> None
diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 745a6e2a772..642630b201a 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -15,7 +15,7 @@ def test_cache_info(script, monkeypatch):
     result = script.pip('cache', 'info')
     cache_dir = _cache_dir(script)
 
-    assert 'Location: %s' % cache_dir in result.stdout
+    assert 'Location: {}'.format(cache_dir) in result.stdout
     # TODO(@duckinator): This should probably test that the number of
     #   packages is actually correct, but I'm not sure how to do that
     #   without pretty much re-implementing the entire cache info command.

From 6fa8498e18e2b054eafd93965c10c1c424889cef Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 14 Jan 2020 14:36:58 -0500
Subject: [PATCH 16/40] [commands/cache] Avoid use of "(s)" suffix.

As @hugovk pointed out, it can cause problems sometimes:

https://github.com/pypa/pip/pull/6391#discussion_r366259867
---
 src/pip/_internal/commands/cache.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 9a473aeefb9..9e106ad7e31 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -133,7 +133,7 @@ def remove_cache_items(self, options, args):
         for filename in files:
             os.unlink(filename)
             logger.debug('Removed %s', filename)
-        logger.info('Removed %s file(s)', len(files))
+        logger.info('Files removed: %s', len(files))
 
     def purge_cache(self, options, args):
         # type: (Values, List[Any]) -> None

From d74895a224594440f7208ec4f8b336377c1b711f Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Sun, 23 Feb 2020 13:49:14 -0500
Subject: [PATCH 17/40] [commands/cache] Normalize path in test.

---
 tests/functional/test_cache.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 642630b201a..b6a3c55e988 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -15,7 +15,7 @@ def test_cache_info(script, monkeypatch):
     result = script.pip('cache', 'info')
     cache_dir = _cache_dir(script)
 
-    assert 'Location: {}'.format(cache_dir) in result.stdout
+    assert 'Location: {}'.format(os.path.normcase(cache_dir)) in result.stdout
     # TODO(@duckinator): This should probably test that the number of
     #   packages is actually correct, but I'm not sure how to do that
     #   without pretty much re-implementing the entire cache info command.

From 10d13762ebab7fa731153fe59fe94d8fae21157a Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Sun, 23 Feb 2020 17:01:44 -0500
Subject: [PATCH 18/40] [commands/cache] Be explicit about `pip cache` only
 working on the wheel cache.

---
 news/6391.feature                      | 2 +-
 src/pip/_internal/commands/__init__.py | 2 +-
 src/pip/_internal/commands/cache.py    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/news/6391.feature b/news/6391.feature
index 73d6dffca8a..e13df852713 100644
--- a/news/6391.feature
+++ b/news/6391.feature
@@ -1 +1 @@
-Add ``pip cache`` command for inspecting/managing pip's cache.
+Add ``pip cache`` command for inspecting/managing pip's wheel cache.
diff --git a/src/pip/_internal/commands/__init__.py b/src/pip/_internal/commands/__init__.py
index 48e288ab345..b43a96c13f3 100644
--- a/src/pip/_internal/commands/__init__.py
+++ b/src/pip/_internal/commands/__init__.py
@@ -66,7 +66,7 @@
     )),
     ('cache', CommandInfo(
         'pip._internal.commands.cache', 'CacheCommand',
-        "Inspect and manage pip's cache.",
+        "Inspect and manage pip's wheel cache.",
     )),
     ('wheel', CommandInfo(
         'pip._internal.commands.wheel', 'WheelCommand',
diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 9e106ad7e31..455064a0d24 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -20,7 +20,7 @@
 
 class CacheCommand(Command):
     """
-        Inspect and manage pip's cache.
+        Inspect and manage pip's wheel cache.
 
         Subcommands:
 

From d9dc76e9094ba1e06224d140ffc5712488114d9f Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Wed, 4 Mar 2020 12:03:36 -0500
Subject: [PATCH 19/40] [commands/cache] Correct argument name in documentation
 for `pip cache list`.

---
 src/pip/_internal/commands/cache.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 455064a0d24..8ef507941d5 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -38,7 +38,7 @@ class CacheCommand(Command):
 
     usage = """
         %prog info
-        %prog list [name]
+        %prog list [<pattern>]
         %prog remove <pattern>
         %prog purge
     """

From f22f69e9bdb20677ff88fadd94941d455fccc6eb Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Wed, 4 Mar 2020 12:09:19 -0500
Subject: [PATCH 20/40] [utils/filesystem] Convert `size` to float, for
 consistent behavior between Py2 and Py3.

---
 src/pip/_internal/utils/filesystem.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/pip/_internal/utils/filesystem.py b/src/pip/_internal/utils/filesystem.py
index 7e369e4a843..adfcd8f106f 100644
--- a/src/pip/_internal/utils/filesystem.py
+++ b/src/pip/_internal/utils/filesystem.py
@@ -192,6 +192,7 @@ def find_files(path, pattern):
 
 def _friendly_size(size):
     # type: (Union[float, int]) -> str
+    size = float(size)  # for consistent behavior between Python 2 and Python 3.
     suffix = 'B'
     if size > 1000:
         size /= 1000

From 03d5ec10f20406f4ba94e5dd2f81f8759f9cace3 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Wed, 4 Mar 2020 12:12:39 -0500
Subject: [PATCH 21/40] [utils/filesystem] Reformat comment to keep lines <79
 characters long.

---
 src/pip/_internal/utils/filesystem.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/pip/_internal/utils/filesystem.py b/src/pip/_internal/utils/filesystem.py
index adfcd8f106f..ea573dbe9ee 100644
--- a/src/pip/_internal/utils/filesystem.py
+++ b/src/pip/_internal/utils/filesystem.py
@@ -192,7 +192,11 @@ def find_files(path, pattern):
 
 def _friendly_size(size):
     # type: (Union[float, int]) -> str
-    size = float(size)  # for consistent behavior between Python 2 and Python 3.
+
+    # Explicitly convert `size` to a float, for consistent behavior
+    # between Python 2 and Python 3.
+    size = float(size)
+
     suffix = 'B'
     if size > 1000:
         size /= 1000

From 735375fb6bd99d150d833684a219c4f17eadb64e Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <the@smallest.dog>
Date: Thu, 5 Mar 2020 08:25:09 -0500
Subject: [PATCH 22/40] [commands/cache] Reformat documentation.

Co-Authored-By: Pradyun Gedam <pradyunsg@gmail.com>
---
 src/pip/_internal/commands/cache.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 8ef507941d5..fc46f9d6b12 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -24,14 +24,10 @@ class CacheCommand(Command):
 
         Subcommands:
 
-        info:
-            Show information about the cache.
-        list:
-            List filenames of packages stored in the cache.
-        remove:
-            Remove one or more package from the cache.
-        purge:
-            Remove all items from the cache.
+        info: Show information about the cache.
+        list: List filenames of packages stored in the cache.
+        remove: Remove one or more package from the cache.
+        purge: Remove all items from the cache.
 
         <pattern> can be a glob expression or a package name.
     """

From 8cd8c91491c904b2536bc79ec16ae6ac396b5818 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <the@smallest.dog>
Date: Thu, 5 Mar 2020 08:25:41 -0500
Subject: [PATCH 23/40] [commands/cache] Reformat (more) documentation.

Co-Authored-By: Pradyun Gedam <pradyunsg@gmail.com>
---
 src/pip/_internal/commands/cache.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index fc46f9d6b12..4d557a0f92c 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -20,9 +20,9 @@
 
 class CacheCommand(Command):
     """
-        Inspect and manage pip's wheel cache.
+    Inspect and manage pip's wheel cache.
 
-        Subcommands:
+    Subcommands:
 
         info: Show information about the cache.
         list: List filenames of packages stored in the cache.

From 63ba6cce4ad4f77696eeca8a13dcccb8af9c02c4 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 5 Mar 2020 08:36:35 -0500
Subject: [PATCH 24/40] [command/cache, utils/filesystem] Use existing
 format_size; remove _friendly_size; rename friendly_*_size to format_*_size
 for consistency.

---
 src/pip/_internal/commands/cache.py   |  4 ++--
 src/pip/_internal/utils/filesystem.py | 34 ++++-----------------------
 2 files changed, 7 insertions(+), 31 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 4d557a0f92c..2f1ad977519 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -75,7 +75,7 @@ def get_cache_info(self, options, args):
         num_packages = len(self._find_wheels(options, '*'))
 
         cache_location = self._wheels_cache_dir(options)
-        cache_size = filesystem.friendly_directory_size(cache_location)
+        cache_size = filesystem.format_directory_size(cache_location)
 
         message = textwrap.dedent("""
             Cache info:
@@ -109,7 +109,7 @@ def list_cache_items(self, options, args):
         results = []
         for filename in files:
             wheel = os.path.basename(filename)
-            size = filesystem.friendly_file_size(filename)
+            size = filesystem.format_file_size(filename)
             results.append(' - {} ({})'.format(wheel, size))
         logger.info('Cache contents:\n')
         logger.info('\n'.join(sorted(results)))
diff --git a/src/pip/_internal/utils/filesystem.py b/src/pip/_internal/utils/filesystem.py
index ea573dbe9ee..d97992acb48 100644
--- a/src/pip/_internal/utils/filesystem.py
+++ b/src/pip/_internal/utils/filesystem.py
@@ -15,6 +15,7 @@
 from pip._vendor.six import PY2
 
 from pip._internal.utils.compat import get_path_uid
+from pip._internal.utils.misc import format_size
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING, cast
 
 if MYPY_CHECK_RUNNING:
@@ -190,31 +191,6 @@ def find_files(path, pattern):
     return result
 
 
-def _friendly_size(size):
-    # type: (Union[float, int]) -> str
-
-    # Explicitly convert `size` to a float, for consistent behavior
-    # between Python 2 and Python 3.
-    size = float(size)
-
-    suffix = 'B'
-    if size > 1000:
-        size /= 1000
-        suffix = 'KB'
-
-    if size > 1000:
-        size /= 1000
-        suffix = 'MB'
-
-    if size > 1000:
-        size /= 1000
-        suffix = 'GB'
-
-    size = round(size, 1)
-
-    return '{} {}'.format(size, suffix)
-
-
 def file_size(path):
     # type: (str) -> Union[int, float]
     # If it's a symlink, return 0.
@@ -223,9 +199,9 @@ def file_size(path):
     return os.path.getsize(path)
 
 
-def friendly_file_size(path):
+def format_file_size(path):
     # type: (str) -> str
-    return _friendly_size(file_size(path))
+    return format_size(file_size(path))
 
 
 def directory_size(path):
@@ -238,6 +214,6 @@ def directory_size(path):
     return size
 
 
-def friendly_directory_size(path):
+def format_directory_size(path):
     # type: (str) -> str
-    return _friendly_size(directory_size(path))
+    return format_size(directory_size(path))

From ed9f885bd7b99ed09f37d30c64779885b22aae66 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <the@smallest.dog>
Date: Thu, 5 Mar 2020 10:43:44 -0500
Subject: [PATCH 25/40] [commands/cache] Reformat output of `pip cache info`

Co-Authored-By: Pradyun Gedam <pradyunsg@gmail.com>
---
 src/pip/_internal/commands/cache.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index 2f1ad977519..e0d751d8d03 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -78,10 +78,9 @@ def get_cache_info(self, options, args):
         cache_size = filesystem.format_directory_size(cache_location)
 
         message = textwrap.dedent("""
-            Cache info:
-              Location: {location}
-              Packages: {package_count}
-              Size:     {size}
+            Location: {location}
+            Size: {size}
+            Number of wheels: {package_count}
         """).format(
             location=cache_location,
             package_count=num_packages,

From f8b67c8bf14c1cc1afe15eefeef416af8f21bae3 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 5 Mar 2020 11:10:17 -0500
Subject: [PATCH 26/40] [commands/cache] Fix test_cache_info test.

---
 tests/functional/test_cache.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index b6a3c55e988..1b2df3f049e 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -19,7 +19,7 @@ def test_cache_info(script, monkeypatch):
     # TODO(@duckinator): This should probably test that the number of
     #   packages is actually correct, but I'm not sure how to do that
     #   without pretty much re-implementing the entire cache info command.
-    assert 'Packages: ' in result.stdout
+    assert 'Number of wheels: ' in result.stdout
 
 
 def test_cache_list(script, monkeypatch):

From 8b518b258df5a923d27fb7537baae31680474268 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 5 Mar 2020 11:10:39 -0500
Subject: [PATCH 27/40] [commands/cache] Make filenames more realistic in
 tests.

---
 tests/functional/test_cache.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 1b2df3f049e..2cd02829880 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -27,9 +27,9 @@ def test_cache_list(script, monkeypatch):
     wheel_cache_dir = os.path.join(cache_dir, 'wheels')
     destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
     os.makedirs(destination)
-    with open(os.path.join(destination, 'yyy-1.2.3.whl'), 'w'):
+    with open(os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
         pass
-    with open(os.path.join(destination, 'zzz-4.5.6.whl'), 'w'):
+    with open(os.path.join(destination, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
         pass
     result = script.pip('cache', 'list')
     assert 'yyy-1.2.3' in result.stdout
@@ -47,9 +47,9 @@ def test_cache_list_with_pattern(script, monkeypatch):
     wheel_cache_dir = os.path.join(cache_dir, 'wheels')
     destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
     os.makedirs(destination)
-    with open(os.path.join(destination, 'yyy-1.2.3.whl'), 'w'):
+    with open(os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
         pass
-    with open(os.path.join(destination, 'zzz-4.5.6.whl'), 'w'):
+    with open(os.path.join(destination, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
         pass
     result = script.pip('cache', 'list', 'zzz')
     assert 'yyy-1.2.3' not in result.stdout
@@ -62,9 +62,9 @@ def test_cache_remove(script, monkeypatch):
     wheel_cache_dir = os.path.join(cache_dir, 'wheels')
     destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
     os.makedirs(destination)
-    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3.whl'), 'w'):
+    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
         pass
-    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6.whl'), 'w'):
+    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
         pass
 
     script.pip('cache', 'remove', expect_error=True)
@@ -84,9 +84,9 @@ def test_cache_purge(script, monkeypatch):
     wheel_cache_dir = os.path.join(cache_dir, 'wheels')
     destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
     os.makedirs(destination)
-    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3.whl'), 'w'):
+    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
         pass
-    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6.whl'), 'w'):
+    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
         pass
 
     result = script.pip('cache', 'purge', 'aaa', '--verbose',

From d57407a37d788719f93757b7345acce7fda185b0 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 5 Mar 2020 13:44:25 -0500
Subject: [PATCH 28/40] [commands/cache] Make _find_wheels(), and this `pip
 cache {list,remove}` behave more predictably.

---
 src/pip/_internal/commands/cache.py | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index e0d751d8d03..af97b40217c 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -144,4 +144,23 @@ def _wheels_cache_dir(self, options):
     def _find_wheels(self, options, pattern):
         # type: (Values, str) -> List[str]
         wheel_dir = self._wheels_cache_dir(options)
-        return filesystem.find_files(wheel_dir, pattern + '*.whl')
+
+        # The wheel filename format, as specified in PEP 427, is:
+        #     {distribution}-{version}(-{build})?-{python}-{abi}-{platform}.whl
+        #
+        # Additionally, non-alphanumeric values in the distribution are
+        # normalized to underscores (_), meaning hyphens can never occur
+        # before `-{version}`.
+        #
+        # Given that information:
+        # - If the pattern we're given contains a hyphen (-), the user is
+        #   providing at least the version. Thus, we can just append `*.whl`
+        #   to match the rest of it.
+        # - If the pattern we're given doesn't contain a hyphen (-), the
+        #   user is only providing the name. Thus, we append `-*.whl` to
+        #   match the hyphen before the version, followed by anything else.
+        #
+        # PEP 427: https://www.python.org/dev/peps/pep-0427/
+        pattern = pattern + ("*.whl" if "-" in pattern else "-*.whl")
+
+        return filesystem.find_files(wheel_dir, pattern)

From e1fde1facaf44ab37882b74d14ab305d422bcd22 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 5 Mar 2020 13:47:25 -0500
Subject: [PATCH 29/40] [commands/cache] Remove unnecessary re-definition of
 __init__.

---
 src/pip/_internal/commands/cache.py | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index af97b40217c..fc63d5eeceb 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -39,10 +39,6 @@ class CacheCommand(Command):
         %prog purge
     """
 
-    def __init__(self, *args, **kw):
-        # type: (*Any, **Any) -> None
-        super(CacheCommand, self).__init__(*args, **kw)
-
     def run(self, options, args):
         # type: (Values, List[Any]) -> int
         handlers = {

From e804aa56aff9048c58b6099af121aa6cebb7a299 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Thu, 5 Mar 2020 13:49:50 -0500
Subject: [PATCH 30/40] [commands/cache] Have `pip cache info` raise an
 exception if it gets any arguments.

---
 src/pip/_internal/commands/cache.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/pip/_internal/commands/cache.py b/src/pip/_internal/commands/cache.py
index fc63d5eeceb..7e3f72e080b 100644
--- a/src/pip/_internal/commands/cache.py
+++ b/src/pip/_internal/commands/cache.py
@@ -68,6 +68,9 @@ def run(self, options, args):
 
     def get_cache_info(self, options, args):
         # type: (Values, List[Any]) -> None
+        if args:
+            raise CommandError('Too many arguments')
+
         num_packages = len(self._find_wheels(options, '*'))
 
         cache_location = self._wheels_cache_dir(options)

From 6e425d80093b5e440eeb7a6797f13318ae8dc7b2 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Fri, 6 Mar 2020 16:12:55 -0500
Subject: [PATCH 31/40] [tests/functional/cache] Refactor to be less redundant.

---
 tests/functional/test_cache.py | 88 +++++++++++++++-------------------
 1 file changed, 38 insertions(+), 50 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 2cd02829880..00ed6a73eaa 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -11,83 +11,73 @@ def _cache_dir(script):
     return result.stdout.strip()
 
 
-def test_cache_info(script, monkeypatch):
-    result = script.pip('cache', 'info')
+def _wheel_cache_contents(script):
     cache_dir = _cache_dir(script)
+    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
+    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+    os.makedirs(destination)
 
-    assert 'Location: {}'.format(os.path.normcase(cache_dir)) in result.stdout
-    # TODO(@duckinator): This should probably test that the number of
-    #   packages is actually correct, but I'm not sure how to do that
-    #   without pretty much re-implementing the entire cache info command.
-    assert 'Number of wheels: ' in result.stdout
+    files = [
+        ('yyy-1.2.3', os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl')),
+        ('zzz-4.5.6', os.path.join(destination, 'zzz-4.5.6-py27-none-any.whl')),
+    ]
+
+    for _name, filename in files:
+        with open(filename, 'w'):
+            pass
 
+    return files
 
-def test_cache_list(script, monkeypatch):
+
+def test_cache_info(script):
     cache_dir = _cache_dir(script)
-    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
-    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
-    os.makedirs(destination)
-    with open(os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
-        pass
-    with open(os.path.join(destination, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
-        pass
+    cache_files = _wheel_cache_contents(script)
+
+    result = script.pip('cache', 'info')
+
+    assert 'Location: {}'.format(os.path.normcase(cache_dir)) in result.stdout
+    assert 'Number of wheels: {}'.format(len(cache_files)) in result.stdout
+
+
+def test_cache_list(script):
+    cache_files = _wheel_cache_contents(script)
+    packages = [name for (name, _path) in cache_files]
     result = script.pip('cache', 'list')
-    assert 'yyy-1.2.3' in result.stdout
-    assert 'zzz-4.5.6' in result.stdout
-    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
+    for package in packages:
+        assert package in result.stdout
+    # assert 'yyy-1.2.3' in result.stdout
+    # assert 'zzz-4.5.6' in result.stdout
 
 
-def test_cache_list_too_many_args(script, monkeypatch):
+def test_cache_list_too_many_args(script):
     script.pip('cache', 'list', 'aaa', 'bbb',
                expect_error=True)
 
 
-def test_cache_list_with_pattern(script, monkeypatch):
-    cache_dir = _cache_dir(script)
-    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
-    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
-    os.makedirs(destination)
-    with open(os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
-        pass
-    with open(os.path.join(destination, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
-        pass
+def test_cache_list_with_pattern(script):
+    cache_files = _wheel_cache_contents(script)
+
     result = script.pip('cache', 'list', 'zzz')
     assert 'yyy-1.2.3' not in result.stdout
     assert 'zzz-4.5.6' in result.stdout
-    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
 
 
 def test_cache_remove(script, monkeypatch):
-    cache_dir = _cache_dir(script)
-    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
-    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
-    os.makedirs(destination)
-    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
-        pass
-    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
-        pass
+    cache_files = _wheel_cache_contents(script)
 
     script.pip('cache', 'remove', expect_error=True)
     result = script.pip('cache', 'remove', 'zzz', '--verbose')
     assert 'yyy-1.2.3' not in result.stdout
     assert 'zzz-4.5.6' in result.stdout
-    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))
 
 
-def test_cache_remove_too_many_args(script, monkeypatch):
+def test_cache_remove_too_many_args(script):
     script.pip('cache', 'remove', 'aaa', 'bbb',
                expect_error=True)
 
 
-def test_cache_purge(script, monkeypatch):
-    cache_dir = _cache_dir(script)
-    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
-    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
-    os.makedirs(destination)
-    with open(os.path.join(wheel_cache_dir, 'yyy-1.2.3-py3-none-any.whl'), 'w'):
-        pass
-    with open(os.path.join(wheel_cache_dir, 'zzz-4.5.6-py27-none-any.whl'), 'w'):
-        pass
+def test_cache_purge(script):
+    cache_files = _wheel_cache_contents(script)
 
     result = script.pip('cache', 'purge', 'aaa', '--verbose',
                         expect_error=True)
@@ -97,5 +87,3 @@ def test_cache_purge(script, monkeypatch):
     result = script.pip('cache', 'purge', '--verbose')
     assert 'yyy-1.2.3' in result.stdout
     assert 'zzz-4.5.6' in result.stdout
-
-    shutil.rmtree(os.path.join(wheel_cache_dir, 'arbitrary'))

From 274b295bd8181444e2d87d0d722858955c841bfd Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Fri, 6 Mar 2020 17:09:40 -0500
Subject: [PATCH 32/40] [tests/functional/cache] Make fixtures feel less
 magical.

It bothered me that _whether or not a function had a certain argument_
dictated the contents of a directory. Pytest fixtures are inherently
kinda magical, but that was a bit much for me.
---
 tests/functional/test_cache.py | 58 ++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 24 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 00ed6a73eaa..a3fd5e5a489 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -1,8 +1,11 @@
 import os
-import shutil
+from glob import glob
 
+import pytest
 
-def _cache_dir(script):
+
+@pytest.fixture
+def cache_dir(script):
     result = script.run(
         'python', '-c',
         'from pip._internal.locations import USER_CACHE_DIR;'
@@ -11,9 +14,23 @@ def _cache_dir(script):
     return result.stdout.strip()
 
 
-def _wheel_cache_contents(script):
-    cache_dir = _cache_dir(script)
-    wheel_cache_dir = os.path.join(cache_dir, 'wheels')
+@pytest.fixture
+def wheel_cache_dir(cache_dir):
+    return os.path.join(cache_dir, 'wheels')
+
+
+@pytest.fixture
+def wheel_cache_files(wheel_cache_dir):
+    destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+    filenames = glob(os.path.join(destination, '*.whl'))
+    files = []
+    for filename in filenames:
+        files.append(os.path.join(destination, filename))
+    return files
+
+
+@pytest.fixture
+def populate_wheel_cache(wheel_cache_dir):
     destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
     os.makedirs(destination)
 
@@ -29,24 +46,20 @@ def _wheel_cache_contents(script):
     return files
 
 
-def test_cache_info(script):
-    cache_dir = _cache_dir(script)
-    cache_files = _wheel_cache_contents(script)
-
+@pytest.mark.usefixtures("populate_wheel_cache")
+def test_cache_info(script, wheel_cache_dir, wheel_cache_files):
     result = script.pip('cache', 'info')
 
-    assert 'Location: {}'.format(os.path.normcase(cache_dir)) in result.stdout
-    assert 'Number of wheels: {}'.format(len(cache_files)) in result.stdout
+    assert 'Location: {}'.format(os.path.normcase(wheel_cache_dir)) in result.stdout
+    assert 'Number of wheels: {}'.format(len(wheel_cache_files)) in result.stdout
 
 
+@pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_list(script):
-    cache_files = _wheel_cache_contents(script)
-    packages = [name for (name, _path) in cache_files]
     result = script.pip('cache', 'list')
-    for package in packages:
-        assert package in result.stdout
-    # assert 'yyy-1.2.3' in result.stdout
-    # assert 'zzz-4.5.6' in result.stdout
+
+    assert 'yyy-1.2.3' in result.stdout
+    assert 'zzz-4.5.6' in result.stdout
 
 
 def test_cache_list_too_many_args(script):
@@ -54,17 +67,15 @@ def test_cache_list_too_many_args(script):
                expect_error=True)
 
 
+@pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_list_with_pattern(script):
-    cache_files = _wheel_cache_contents(script)
-
     result = script.pip('cache', 'list', 'zzz')
     assert 'yyy-1.2.3' not in result.stdout
     assert 'zzz-4.5.6' in result.stdout
 
 
-def test_cache_remove(script, monkeypatch):
-    cache_files = _wheel_cache_contents(script)
-
+@pytest.mark.usefixtures("populate_wheel_cache")
+def test_cache_remove(script):
     script.pip('cache', 'remove', expect_error=True)
     result = script.pip('cache', 'remove', 'zzz', '--verbose')
     assert 'yyy-1.2.3' not in result.stdout
@@ -76,9 +87,8 @@ def test_cache_remove_too_many_args(script):
                expect_error=True)
 
 
+@pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_purge(script):
-    cache_files = _wheel_cache_contents(script)
-
     result = script.pip('cache', 'purge', 'aaa', '--verbose',
                         expect_error=True)
     assert 'yyy-1.2.3' not in result.stdout

From c6b5a52a5ab794cfc433b93e9c4a54c6fdff50d6 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Fri, 6 Mar 2020 21:26:04 -0500
Subject: [PATCH 33/40] [tests/functional/test_cache] Always call normcase on
 cache dir; fix line length problems.

---
 tests/functional/test_cache.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index a3fd5e5a489..be4e5589e36 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -16,7 +16,7 @@ def cache_dir(script):
 
 @pytest.fixture
 def wheel_cache_dir(cache_dir):
-    return os.path.join(cache_dir, 'wheels')
+    return os.path.normcase(os.path.join(cache_dir, 'wheels'))
 
 
 @pytest.fixture
@@ -36,7 +36,7 @@ def populate_wheel_cache(wheel_cache_dir):
 
     files = [
         ('yyy-1.2.3', os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl')),
-        ('zzz-4.5.6', os.path.join(destination, 'zzz-4.5.6-py27-none-any.whl')),
+        ('zzz-4.5.6', os.path.join(destination, 'zzz-4.5.6-py3-none-any.whl')),
     ]
 
     for _name, filename in files:
@@ -50,8 +50,9 @@ def populate_wheel_cache(wheel_cache_dir):
 def test_cache_info(script, wheel_cache_dir, wheel_cache_files):
     result = script.pip('cache', 'info')
 
-    assert 'Location: {}'.format(os.path.normcase(wheel_cache_dir)) in result.stdout
-    assert 'Number of wheels: {}'.format(len(wheel_cache_files)) in result.stdout
+    assert 'Location: {}'.format(wheel_cache_dir) in result.stdout
+    num_wheels = len(wheel_cache_files)
+    assert 'Number of wheels: {}'.format(num_wheels) in result.stdout
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")

From 32ce3bacbe0893bc0ceb326b8df98ac9300a6915 Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 10 Mar 2020 12:44:33 -0400
Subject: [PATCH 34/40] [tests/functional/cache] Rewrite all of the pip cache
 {list,remove} tests.

---
 tests/functional/test_cache.py | 106 +++++++++++++++++++++++++++++----
 1 file changed, 95 insertions(+), 11 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index be4e5589e36..9311c6ffcf8 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -1,4 +1,5 @@
 import os
+import re
 from glob import glob
 
 import pytest
@@ -37,6 +38,8 @@ def populate_wheel_cache(wheel_cache_dir):
     files = [
         ('yyy-1.2.3', os.path.join(destination, 'yyy-1.2.3-py3-none-any.whl')),
         ('zzz-4.5.6', os.path.join(destination, 'zzz-4.5.6-py3-none-any.whl')),
+        ('zzz-4.5.7', os.path.join(destination, 'zzz-4.5.7-py3-none-any.whl')),
+        ('zzz-7.8.9', os.path.join(destination, 'zzz-7.8.9-py3-none-any.whl')),
     ]
 
     for _name, filename in files:
@@ -46,6 +49,38 @@ def populate_wheel_cache(wheel_cache_dir):
     return files
 
 
+def list_matches_wheel(wheel_name, lines):
+    """Returns True if any line in `lines`, which should be the output of
+    a `pip cache list` call, matches `wheel_name`.
+
+    E.g., If wheel_name is `foo-1.2.3` it searches for a line starting with
+          `- foo-1.2.3-py3-none-any.whl `."""
+    expected = ' - {}-py3-none-any.whl '.format(wheel_name)
+    return any(map(lambda l: l.startswith(expected), lines))
+
+
+@pytest.fixture
+def remove_matches_wheel(wheel_cache_dir):
+    """Returns True if any line in `lines`, which should be the output of
+    a `pip cache remove`/`pip cache purge` call, matches `wheel_name`.
+
+    E.g., If wheel_name is `foo-1.2.3`, it searches for a line equal to
+    `Removed <wheel cache dir>/arbitrary/pathname/foo-1.2.3-py3-none-any.whl`.
+    """
+
+    def _remove_matches_wheel(wheel_name, lines):
+        wheel_filename = '{}-py3-none-any.whl'.format(wheel_name)
+
+        # The "/arbitrary/pathname/" bit is an implementation detail of how
+        # the `populate_wheel_cache` fixture is implemented.
+        expected = 'Removed {}/arbitrary/pathname/{}'.format(
+            wheel_cache_dir, wheel_filename,
+        )
+        return expected in lines
+
+    return _remove_matches_wheel
+
+
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_info(script, wheel_cache_dir, wheel_cache_files):
     result = script.pip('cache', 'info')
@@ -57,37 +92,86 @@ def test_cache_info(script, wheel_cache_dir, wheel_cache_files):
 
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_list(script):
+    """Running `pip cache list` should return exactly what the
+    populate_wheel_cache fixture adds."""
     result = script.pip('cache', 'list')
-
-    assert 'yyy-1.2.3' in result.stdout
-    assert 'zzz-4.5.6' in result.stdout
+    lines = result.stdout.splitlines()
+    assert list_matches_wheel('yyy-1.2.3', lines)
+    assert list_matches_wheel('zzz-4.5.6', lines)
+    assert list_matches_wheel('zzz-4.5.7', lines)
+    assert list_matches_wheel('zzz-7.8.9', lines)
 
 
 def test_cache_list_too_many_args(script):
+    """Passing `pip cache list` too many arguments should cause an error."""
     script.pip('cache', 'list', 'aaa', 'bbb',
                expect_error=True)
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
-def test_cache_list_with_pattern(script):
-    result = script.pip('cache', 'list', 'zzz')
-    assert 'yyy-1.2.3' not in result.stdout
-    assert 'zzz-4.5.6' in result.stdout
+def test_cache_list_name_match(script):
+    """Running `pip cache list zzz` should list zzz-4.5.6, zzz-4.5.7,
+    zzz-7.8.9, but nothing else."""
+    result = script.pip('cache', 'list', 'zzz', '--verbose')
+    lines = result.stdout.splitlines()
+
+    assert not list_matches_wheel('yyy-1.2.3', lines)
+    assert list_matches_wheel('zzz-4.5.6', lines)
+    assert list_matches_wheel('zzz-4.5.7', lines)
+    assert list_matches_wheel('zzz-7.8.9', lines)
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
-def test_cache_remove(script):
+def test_cache_list_name_and_version_match(script):
+    """Running `pip cache list zzz-4.5.6` should list zzz-4.5.6, but
+    nothing else."""
+    result = script.pip('cache', 'list', 'zzz-4.5.6', '--verbose')
+    lines = result.stdout.splitlines()
+
+    assert not list_matches_wheel('yyy-1.2.3', lines)
+    assert list_matches_wheel('zzz-4.5.6', lines)
+    assert not list_matches_wheel('zzz-4.5.7', lines)
+    assert not list_matches_wheel('zzz-7.8.9', lines)
+
+
+@pytest.mark.usefixture("populate_wheel_cache")
+def test_cache_remove_no_arguments(script):
+    """Running `pip cache remove` with no arguments should cause an error."""
     script.pip('cache', 'remove', expect_error=True)
-    result = script.pip('cache', 'remove', 'zzz', '--verbose')
-    assert 'yyy-1.2.3' not in result.stdout
-    assert 'zzz-4.5.6' in result.stdout
 
 
 def test_cache_remove_too_many_args(script):
+    """Passing `pip cache remove` too many arguments should cause an error."""
     script.pip('cache', 'remove', 'aaa', 'bbb',
                expect_error=True)
 
 
+@pytest.mark.usefixtures("populate_wheel_cache")
+def test_cache_remove_name_match(script, remove_matches_wheel):
+    """Running `pip cache remove zzz` should remove zzz-4.5.6 and zzz-7.8.9,
+    but nothing else."""
+    result = script.pip('cache', 'remove', 'zzz', '--verbose')
+    lines = result.stdout.splitlines()
+
+    assert not remove_matches_wheel('yyy-1.2.3', lines)
+    assert remove_matches_wheel('zzz-4.5.6', lines)
+    assert remove_matches_wheel('zzz-4.5.7', lines)
+    assert remove_matches_wheel('zzz-7.8.9', lines)
+
+
+@pytest.mark.usefixtures("populate_wheel_cache")
+def test_cache_remove_name_and_version_match(script, remove_matches_wheel):
+    """Running `pip cache remove zzz-4.5.6` should remove zzz-4.5.6, but
+    nothing else."""
+    result = script.pip('cache', 'remove', 'zzz-4.5.6', '--verbose')
+    lines = result.stdout.splitlines()
+
+    assert not remove_matches_wheel('yyy-1.2.3', lines)
+    assert remove_matches_wheel('zzz-4.5.6', lines)
+    assert not remove_matches_wheel('zzz-4.5.7', lines)
+    assert not remove_matches_wheel('zzz-7.8.9', lines)
+
+
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_purge(script):
     result = script.pip('cache', 'purge', 'aaa', '--verbose',

From ba7c3ac9ec450452ec14e872bc9d6551dffc3d3b Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 10 Mar 2020 14:53:24 -0400
Subject: [PATCH 35/40] [tests/functional/test_cache] Add test `pip cache list`
 with an empty cache.

---
 tests/functional/test_cache.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 9311c6ffcf8..55080dbf4f2 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -1,5 +1,6 @@
 import os
 import re
+import shutil
 from glob import glob
 
 import pytest
@@ -23,6 +24,10 @@ def wheel_cache_dir(cache_dir):
 @pytest.fixture
 def wheel_cache_files(wheel_cache_dir):
     destination = os.path.join(wheel_cache_dir, 'arbitrary', 'pathname')
+
+    if not os.path.exists(destination):
+        return []
+
     filenames = glob(os.path.join(destination, '*.whl'))
     files = []
     for filename in filenames:
@@ -49,6 +54,12 @@ def populate_wheel_cache(wheel_cache_dir):
     return files
 
 
+@pytest.fixture
+def empty_wheel_cache(wheel_cache_dir):
+    if os.path.exists(wheel_cache_dir):
+        shutil.rmtree(wheel_cache_dir)
+
+
 def list_matches_wheel(wheel_name, lines):
     """Returns True if any line in `lines`, which should be the output of
     a `pip cache list` call, matches `wheel_name`.
@@ -102,6 +113,14 @@ def test_cache_list(script):
     assert list_matches_wheel('zzz-7.8.9', lines)
 
 
+@pytest.mark.usefixtures("empty_wheel_cache")
+def test_cache_list_with_empty_cache(script):
+    """Running `pip cache list` with an empty cache should print
+    "Nothing cached." and exit."""
+    result = script.pip('cache', 'list')
+    assert result.stdout == "Nothing cached.\n"
+
+
 def test_cache_list_too_many_args(script):
     """Passing `pip cache list` too many arguments should cause an error."""
     script.pip('cache', 'list', 'aaa', 'bbb',

From a20b28d0080cc69ff0fd901c15be5a7c11faeeee Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 10 Mar 2020 15:04:07 -0400
Subject: [PATCH 36/40] [tests/functional/test_cache] Split apart tests for
 `pip cache purge`.

---
 tests/functional/test_cache.py | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 55080dbf4f2..37a0de0737e 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -192,12 +192,23 @@ def test_cache_remove_name_and_version_match(script, remove_matches_wheel):
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
-def test_cache_purge(script):
+def test_cache_purge(script, remove_matches_wheel):
+    result = script.pip('cache', 'purge', '--verbose')
+    lines = result.stdout.splitlines()
+
+    assert remove_matches_wheel('yyy-1.2.3', lines)
+    assert remove_matches_wheel('zzz-4.5.6', lines)
+    assert remove_matches_wheel('zzz-4.5.7', lines)
+    assert remove_matches_wheel('zzz-7.8.9', lines)
+
+
+@pytest.mark.usefixtures("populate_wheel_cache")
+def test_cache_purge_too_many_args(script, wheel_cache_files):
     result = script.pip('cache', 'purge', 'aaa', '--verbose',
                         expect_error=True)
-    assert 'yyy-1.2.3' not in result.stdout
-    assert 'zzz-4.5.6' not in result.stdout
+    assert result.stdout == ''
+    assert result.stderr == 'ERROR: Too many arguments\n'
 
-    result = script.pip('cache', 'purge', '--verbose')
-    assert 'yyy-1.2.3' in result.stdout
-    assert 'zzz-4.5.6' in result.stdout
+    # Make sure nothing was deleted.
+    for filename in wheel_cache_files:
+        assert os.path.exists(filename)

From 88582379038dbb91c13d5bc1b78ed5585e994cfb Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 10 Mar 2020 15:08:18 -0400
Subject: [PATCH 37/40] [tests/functional/test_cache] Refactor
 list_matches_wheel() and remove_matches_wheel().

---
 tests/functional/test_cache.py | 69 +++++++++++++++++-----------------
 1 file changed, 35 insertions(+), 34 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 37a0de0737e..aa8dc13082f 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -60,26 +60,29 @@ def empty_wheel_cache(wheel_cache_dir):
         shutil.rmtree(wheel_cache_dir)
 
 
-def list_matches_wheel(wheel_name, lines):
-    """Returns True if any line in `lines`, which should be the output of
+def list_matches_wheel(wheel_name, result):
+    """Returns True if any line in `result`, which should be the output of
     a `pip cache list` call, matches `wheel_name`.
 
     E.g., If wheel_name is `foo-1.2.3` it searches for a line starting with
           `- foo-1.2.3-py3-none-any.whl `."""
+    lines = result.stdout.splitlines()
     expected = ' - {}-py3-none-any.whl '.format(wheel_name)
     return any(map(lambda l: l.startswith(expected), lines))
 
 
 @pytest.fixture
 def remove_matches_wheel(wheel_cache_dir):
-    """Returns True if any line in `lines`, which should be the output of
+    """Returns True if any line in `result`, which should be the output of
     a `pip cache remove`/`pip cache purge` call, matches `wheel_name`.
 
     E.g., If wheel_name is `foo-1.2.3`, it searches for a line equal to
     `Removed <wheel cache dir>/arbitrary/pathname/foo-1.2.3-py3-none-any.whl`.
     """
 
-    def _remove_matches_wheel(wheel_name, lines):
+    def _remove_matches_wheel(wheel_name, result):
+        lines = result.stdout.splitlines()
+
         wheel_filename = '{}-py3-none-any.whl'.format(wheel_name)
 
         # The "/arbitrary/pathname/" bit is an implementation detail of how
@@ -106,11 +109,11 @@ def test_cache_list(script):
     """Running `pip cache list` should return exactly what the
     populate_wheel_cache fixture adds."""
     result = script.pip('cache', 'list')
-    lines = result.stdout.splitlines()
-    assert list_matches_wheel('yyy-1.2.3', lines)
-    assert list_matches_wheel('zzz-4.5.6', lines)
-    assert list_matches_wheel('zzz-4.5.7', lines)
-    assert list_matches_wheel('zzz-7.8.9', lines)
+
+    assert list_matches_wheel('yyy-1.2.3', result)
+    assert list_matches_wheel('zzz-4.5.6', result)
+    assert list_matches_wheel('zzz-4.5.7', result)
+    assert list_matches_wheel('zzz-7.8.9', result)
 
 
 @pytest.mark.usefixtures("empty_wheel_cache")
@@ -132,12 +135,11 @@ def test_cache_list_name_match(script):
     """Running `pip cache list zzz` should list zzz-4.5.6, zzz-4.5.7,
     zzz-7.8.9, but nothing else."""
     result = script.pip('cache', 'list', 'zzz', '--verbose')
-    lines = result.stdout.splitlines()
 
-    assert not list_matches_wheel('yyy-1.2.3', lines)
-    assert list_matches_wheel('zzz-4.5.6', lines)
-    assert list_matches_wheel('zzz-4.5.7', lines)
-    assert list_matches_wheel('zzz-7.8.9', lines)
+    assert not list_matches_wheel('yyy-1.2.3', result)
+    assert list_matches_wheel('zzz-4.5.6', result)
+    assert list_matches_wheel('zzz-4.5.7', result)
+    assert list_matches_wheel('zzz-7.8.9', result)
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
@@ -145,12 +147,11 @@ def test_cache_list_name_and_version_match(script):
     """Running `pip cache list zzz-4.5.6` should list zzz-4.5.6, but
     nothing else."""
     result = script.pip('cache', 'list', 'zzz-4.5.6', '--verbose')
-    lines = result.stdout.splitlines()
 
-    assert not list_matches_wheel('yyy-1.2.3', lines)
-    assert list_matches_wheel('zzz-4.5.6', lines)
-    assert not list_matches_wheel('zzz-4.5.7', lines)
-    assert not list_matches_wheel('zzz-7.8.9', lines)
+    assert not list_matches_wheel('yyy-1.2.3', result)
+    assert list_matches_wheel('zzz-4.5.6', result)
+    assert not list_matches_wheel('zzz-4.5.7', result)
+    assert not list_matches_wheel('zzz-7.8.9', result)
 
 
 @pytest.mark.usefixture("populate_wheel_cache")
@@ -170,12 +171,11 @@ def test_cache_remove_name_match(script, remove_matches_wheel):
     """Running `pip cache remove zzz` should remove zzz-4.5.6 and zzz-7.8.9,
     but nothing else."""
     result = script.pip('cache', 'remove', 'zzz', '--verbose')
-    lines = result.stdout.splitlines()
 
-    assert not remove_matches_wheel('yyy-1.2.3', lines)
-    assert remove_matches_wheel('zzz-4.5.6', lines)
-    assert remove_matches_wheel('zzz-4.5.7', lines)
-    assert remove_matches_wheel('zzz-7.8.9', lines)
+    assert not remove_matches_wheel('yyy-1.2.3', result)
+    assert remove_matches_wheel('zzz-4.5.6', result)
+    assert remove_matches_wheel('zzz-4.5.7', result)
+    assert remove_matches_wheel('zzz-7.8.9', result)
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
@@ -183,27 +183,28 @@ def test_cache_remove_name_and_version_match(script, remove_matches_wheel):
     """Running `pip cache remove zzz-4.5.6` should remove zzz-4.5.6, but
     nothing else."""
     result = script.pip('cache', 'remove', 'zzz-4.5.6', '--verbose')
-    lines = result.stdout.splitlines()
 
-    assert not remove_matches_wheel('yyy-1.2.3', lines)
-    assert remove_matches_wheel('zzz-4.5.6', lines)
-    assert not remove_matches_wheel('zzz-4.5.7', lines)
-    assert not remove_matches_wheel('zzz-7.8.9', lines)
+    assert not remove_matches_wheel('yyy-1.2.3', result)
+    assert remove_matches_wheel('zzz-4.5.6', result)
+    assert not remove_matches_wheel('zzz-4.5.7', result)
+    assert not remove_matches_wheel('zzz-7.8.9', result)
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_purge(script, remove_matches_wheel):
+    """Running `pip cache purge` should remove all cached wheels."""
     result = script.pip('cache', 'purge', '--verbose')
-    lines = result.stdout.splitlines()
 
-    assert remove_matches_wheel('yyy-1.2.3', lines)
-    assert remove_matches_wheel('zzz-4.5.6', lines)
-    assert remove_matches_wheel('zzz-4.5.7', lines)
-    assert remove_matches_wheel('zzz-7.8.9', lines)
+    assert remove_matches_wheel('yyy-1.2.3', result)
+    assert remove_matches_wheel('zzz-4.5.6', result)
+    assert remove_matches_wheel('zzz-4.5.7', result)
+    assert remove_matches_wheel('zzz-7.8.9', result)
 
 
 @pytest.mark.usefixtures("populate_wheel_cache")
 def test_cache_purge_too_many_args(script, wheel_cache_files):
+    """Running `pip cache purge aaa` should raise an error and remove no
+    cached wheels."""
     result = script.pip('cache', 'purge', 'aaa', '--verbose',
                         expect_error=True)
     assert result.stdout == ''

From b7239f5deedbfd030bc9b247214bf8bf590a561a Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 10 Mar 2020 15:40:25 -0400
Subject: [PATCH 38/40] [tests/functional/test_cache] Remove unused import.

---
 tests/functional/test_cache.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index aa8dc13082f..c0112929d9e 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -1,5 +1,4 @@
 import os
-import re
 import shutil
 from glob import glob
 

From 0c4eafad6263fe7e6755635e041cecc390d1a57e Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Tue, 10 Mar 2020 16:00:28 -0400
Subject: [PATCH 39/40] [tests/functional/test_cache] Fix test on Python 2.7.

---
 tests/functional/test_cache.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index c0112929d9e..1ab7fa6457e 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -207,7 +207,10 @@ def test_cache_purge_too_many_args(script, wheel_cache_files):
     result = script.pip('cache', 'purge', 'aaa', '--verbose',
                         expect_error=True)
     assert result.stdout == ''
-    assert result.stderr == 'ERROR: Too many arguments\n'
+
+    # This would be `result.stderr == ...`, but Pip prints deprecation
+    # warnings on Python 2.7, so we check if the _line_ is in stderr.
+    assert 'ERROR: Too many arguments' in result.stderr.splitlines()
 
     # Make sure nothing was deleted.
     for filename in wheel_cache_files:

From b988417b4f0746c70d04f5a78cb92cfe15e338aa Mon Sep 17 00:00:00 2001
From: Ellen Marie Dash <me@duckie.co>
Date: Fri, 13 Mar 2020 17:56:03 -0400
Subject: [PATCH 40/40] [tests/functional/test_cache] Use os.path.join()
 instead of hard-coding the path separator.

---
 tests/functional/test_cache.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/functional/test_cache.py b/tests/functional/test_cache.py
index 1ab7fa6457e..a464ece7945 100644
--- a/tests/functional/test_cache.py
+++ b/tests/functional/test_cache.py
@@ -86,9 +86,10 @@ def _remove_matches_wheel(wheel_name, result):
 
         # The "/arbitrary/pathname/" bit is an implementation detail of how
         # the `populate_wheel_cache` fixture is implemented.
-        expected = 'Removed {}/arbitrary/pathname/{}'.format(
-            wheel_cache_dir, wheel_filename,
+        path = os.path.join(
+            wheel_cache_dir, 'arbitrary', 'pathname', wheel_filename,
         )
+        expected = 'Removed {}'.format(path)
         return expected in lines
 
     return _remove_matches_wheel