test: two tests for #1828

Author: nedbat

coverage/phystokens.py

@@ -57,14 +57,14 @@ def _phys_tokens(toks: TokenInfos) -> TokenInfos:
                 if last_ttext.endswith("\\"):
                     inject_backslash = False
                 elif ttype == token.STRING:
-                    if last_line.endswith(last_ttext+"\\\n"):
+                    if last_line.endswith(last_ttext + "\\\n"):
                         # Deal with special cases like such code::
                         #
                         #   a = ["aaa",\
                         #        "bbb \
                         #        ccc"]
                         #
-                        pass
+                        inject_backslash = True
                     elif "\n" in ttext and ttext.split("\n", 1)[0][-1] == "\\":
                         # It's a multi-line string and the first line ends with
                         # a backslash, so we don't need to inject another.

tests/test_html.py

@@ -1131,6 +1131,28 @@ def test_tabbed(self) -> None:
 
         doesnt_contain("out/tabbed_py.html", "\t")
 
+    def test_bug_1828(self) -> None:
+        # https://github.com/nedbat/coveragepy/pull/1828
+        self.make_file("backslashes.py", """\
+            a = ["aaa",\\
+                 "bbb \\
+                 ccc"]
+            """)
+
+        cov = coverage.Coverage()
+        backslashes = self.start_import_stop(cov, "backslashes")
+        cov.html_report(backslashes, directory="out")
+
+        contains(
+            "out/backslashes_py.html",
+            # line 2 is `"bbb \`
+            r'<a id="t2" href="#t2">2</a></span>'
+                + r'<span class="t">     <span class="str">"bbb \</span>',
+            # line 3 is `ccc"]`
+            r'<a id="t3" href="#t3">3</a></span>'
+                + r'<span class="t"><span class="str">     ccc"</span><span class="op">]</span>',
+        )
+
     def test_unicode(self) -> None:
         surrogate = "\U000e0100"
 

tests/test_phystokens.py

@@ -98,6 +98,24 @@ def test_tokenize_real_file(self) -> None:
         real_file = os.path.join(TESTS_DIR, "test_coverage.py")
         self.check_file_tokenization(real_file)
 
+    def test_1828(self) -> None:
+        # https://github.com/nedbat/coveragepy/pull/1828
+        tokens = list(source_token_lines(textwrap.dedent("""
+            x = \
+                1
+            a = ["aaa",\\
+                 "bbb \\
+                 ccc"]
+            """)))
+        assert tokens == [
+            [],
+            [('nam', 'x'), ('ws', ' '), ('op', '='), ('ws', '                 '), ('num', '1')],
+            [('nam', 'a'), ('ws', ' '), ('op', '='), ('ws', ' '),
+                ('op', '['), ('str', '"aaa"'), ('op', ','), ('xx', '\\')],
+            [('ws', '     '), ('str', '"bbb \\')],
+            [('str', '     ccc"'), ('op', ']')],
+        ]
+
     @pytest.mark.parametrize("fname", [
         "stress_phystoken.tok",
         "stress_phystoken_dos.tok",
@@ -113,6 +131,7 @@ def test_stress(self, fname: str) -> None:
             with open(stress) as fstress:
                 assert re.search(r"(?m) $", fstress.read()), f"{stress} needs a trailing space."
 
+
 @pytest.mark.skipif(not env.PYBEHAVIOR.soft_keywords, reason="Soft keywords are new in Python 3.10")
 class SoftKeywordTest(CoverageTest):
     """Tests the tokenizer handling soft keywords."""