feat: make unwrapSymlink pluggable

SimenB · SimenB · commit 0cf3b33c20b6 · 2020-04-08T00:56:02.000+02:00
diff --git a/lib/async.js b/lib/async.js
@@ -25,12 +25,16 @@ var defaultIsDir = function isDirectory(dir, cb) {
     });
 };
 
-var maybeUnwrapSymlink = function maybeUnwrapSymlink(x, opts, cb) {
+var defaultUnwrapSymlink = function unwrapSymlink(x, cb) {
+    fs.realpath(x, function (realPathErr, realPath) {
+        if (realPathErr && realPathErr.code !== 'ENOENT') cb(realPathErr);
+        else cb(null, realPathErr ? x : realPath);
+    });
+};
+
+var maybeUnwrapSymlink = function maybeUnwrapSymlink(unwrap, x, opts, cb) {
     if (!opts || !opts.preserveSymlinks) {
-        fs.realpath(x, function (realPathErr, realPath) {
-            if (realPathErr && realPathErr.code !== 'ENOENT') cb(realPathErr);
-            else cb(null, realPathErr ? x : realPath);
-        });
+        unwrap(x, cb);
     } else {
         cb(null, x);
     }
@@ -63,6 +67,7 @@ module.exports = function resolve(x, options, callback) {
     var isFile = opts.isFile || defaultIsFile;
     var isDirectory = opts.isDirectory || defaultIsDir;
     var readFile = opts.readFile || fs.readFile;
+    var unwrapSymlink = opts.unwrapSymlink || defaultUnwrapSymlink;
     var packageIterator = opts.packageIterator;
 
     var extensions = opts.extensions || ['.js'];
@@ -75,6 +80,7 @@ module.exports = function resolve(x, options, callback) {
     var absoluteStart = path.resolve(basedir);
 
     maybeUnwrapSymlink(
+        unwrapSymlink,
         absoluteStart,
         opts,
         function (err, realStart) {
@@ -110,7 +116,7 @@ module.exports = function resolve(x, options, callback) {
         } else loadNodeModules(x, basedir, function (err, n, pkg) {
             if (err) cb(err);
             else if (n) {
-                return maybeUnwrapSymlink(n, opts, function (err, realN) {
+                return maybeUnwrapSymlink(unwrapSymlink, n, opts, function (err, realN) {
                     if (err) {
                         cb(err);
                     } else {
@@ -131,7 +137,7 @@ module.exports = function resolve(x, options, callback) {
         else loadAsDirectory(res, function (err, d, pkg) {
             if (err) cb(err);
             else if (d) {
-                maybeUnwrapSymlink(d, opts, function (err, realD) {
+                maybeUnwrapSymlink(unwrapSymlink, d, opts, function (err, realD) {
                     if (err) {
                         cb(err);
                     } else {
@@ -195,7 +201,7 @@ module.exports = function resolve(x, options, callback) {
         }
         if ((/[/\\]node_modules[/\\]*$/).test(dir)) return cb(null);
 
-        maybeUnwrapSymlink(dir, opts, function (unwrapErr, pkgdir) {
+        maybeUnwrapSymlink(unwrapSymlink, dir, opts, function (unwrapErr, pkgdir) {
             if (unwrapErr) return loadpkg(path.dirname(dir), cb);
             var pkgfile = path.join(pkgdir, 'package.json');
             isFile(pkgfile, function (err, ex) {
@@ -223,7 +229,7 @@ module.exports = function resolve(x, options, callback) {
             fpkg = opts.package;
         }
 
-        maybeUnwrapSymlink(x, opts, function (unwrapErr, pkgdir) {
+        maybeUnwrapSymlink(unwrapSymlink, x, opts, function (unwrapErr, pkgdir) {
             if (unwrapErr) return loadAsDirectory(path.dirname(x), fpkg, cb);
             var pkgfile = path.join(pkgdir, 'package.json');
             isFile(pkgfile, function (err, ex) {
diff --git a/lib/sync.js b/lib/sync.js
@@ -25,19 +25,24 @@ var defaultIsDir = function isDirectory(dir) {
     return stat.isDirectory();
 };
 
-var maybeUnwrapSymlink = function maybeUnwrapSymlink(x, opts) {
-    if (!opts || !opts.preserveSymlinks) {
-        try {
-            return fs.realpathSync(x);
-        } catch (realPathErr) {
-            if (realPathErr.code !== 'ENOENT') {
-                throw realPathErr;
-            }
+var defaultUnwrapSymlink = function unwrapSymlink(x) {
+    try {
+        return fs.realpathSync(x);
+    } catch (realPathErr) {
+        if (realPathErr.code !== 'ENOENT') {
+            throw realPathErr;
         }
     }
     return x;
 };
 
+var maybeUnwrapSymlink = function maybeUnwrapSymlink(unwrap, x, opts) {
+    if (!opts || !opts.preserveSymlinks) {
+        return unwrap(x);
+    }
+    return x;
+};
+
 var getPackageCandidates = function getPackageCandidates(x, start, opts) {
     var dirs = nodeModulesPaths(start, opts, x);
     for (var i = 0; i < dirs.length; i++) {
@@ -55,6 +60,7 @@ module.exports = function resolveSync(x, options) {
     var isFile = opts.isFile || defaultIsFile;
     var isDirectory = opts.isDirectory || defaultIsDir;
     var readFileSync = opts.readFileSync || fs.readFileSync;
+    var unwrapSymlink = opts.unwrapSymlink || defaultUnwrapSymlink;
     var packageIterator = opts.packageIterator;
 
     var extensions = opts.extensions || ['.js'];
@@ -64,7 +70,7 @@ module.exports = function resolveSync(x, options) {
     opts.paths = opts.paths || [];
 
     // ensure that `basedir` is an absolute path at this point, resolving against the process' current working directory
-    var absoluteStart = maybeUnwrapSymlink(path.resolve(basedir), opts);
+    var absoluteStart = maybeUnwrapSymlink(unwrapSymlink, path.resolve(basedir), opts);
 
     if (opts.basedir && !isDirectory(absoluteStart)) {
         var dirError = new TypeError('Provided basedir "' + opts.basedir + '" is not a directory' + (opts.preserveSymlinks ? '' : ', or a symlink to a directory'));
@@ -76,12 +82,12 @@ module.exports = function resolveSync(x, options) {
         var res = path.resolve(absoluteStart, x);
         if (x === '.' || x === '..' || x.slice(-1) === '/') res += '/';
         var m = loadAsFileSync(res) || loadAsDirectorySync(res);
-        if (m) return maybeUnwrapSymlink(m, opts);
+        if (m) return maybeUnwrapSymlink(unwrapSymlink, m, opts);
     } else if (isCore(x)) {
         return x;
     } else {
         var n = loadNodeModulesSync(x, absoluteStart);
-        if (n) return maybeUnwrapSymlink(n, opts);
+        if (n) return maybeUnwrapSymlink(unwrapSymlink, n, opts);
     }
 
     var err = new Error("Cannot find module '" + x + "' from '" + parent + "'");
@@ -118,7 +124,7 @@ module.exports = function resolveSync(x, options) {
         }
         if ((/[/\\]node_modules[/\\]*$/).test(dir)) return;
 
-        var pkgfile = path.join(isDirectory(dir) ? maybeUnwrapSymlink(dir, opts) : dir, 'package.json');
+        var pkgfile = path.join(isDirectory(dir) ? maybeUnwrapSymlink(unwrapSymlink, dir, opts) : dir, 'package.json');
 
         if (!isFile(pkgfile)) {
             return loadpkg(path.dirname(dir));
@@ -138,7 +144,7 @@ module.exports = function resolveSync(x, options) {
     }
 
     function loadAsDirectorySync(x) {
-        var pkgfile = path.join(isDirectory(x) ? maybeUnwrapSymlink(x, opts) : x, '/package.json');
+        var pkgfile = path.join(isDirectory(x) ? maybeUnwrapSymlink(unwrapSymlink, x, opts) : x, '/package.json');
         if (isFile(pkgfile)) {
             try {
                 var body = readFileSync(pkgfile, 'UTF8');
diff --git a/readme.markdown b/readme.markdown
@@ -61,6 +61,8 @@ options are:
 
 * opts.isDirectory - function to asynchronously test whether a file exists and is a directory
 
+* opts.unwrapSymlink - function to asynchronously unwrap a potential symlink
+
 * `opts.packageFilter(pkg, pkgfile, dir)` - transform the parsed package.json contents before looking at the "main" field
   * pkg - package data
   * pkgfile - path to package.json
@@ -117,6 +119,12 @@ default `opts` values:
             return cb(err);
         });
     },
+    unwrapSymlink: function unwrapSymlink(file, cb) {
+       fs.realpath(file, function (realPathErr, realPath) {
+           if (realPathErr && realPathErr.code !== 'ENOENT') cb(realPathErr);
+           else cb(null, realPathErr ? file : realPath);
+       });
+   },
     moduleDirectory: 'node_modules',
     preserveSymlinks: false
 }
@@ -139,6 +147,8 @@ options are:
 
 * opts.isDirectory - function to synchronously test whether a file exists and is a directory
 
+* opts.unwrapSymlink - function to synchronously unwrap a potential symlink
+
 * `opts.packageFilter(pkg, pkgfile, dir)` - transform the parsed package.json contents before looking at the "main" field
   * pkg - package data
   * pkgfile - path to package.json
@@ -195,6 +205,16 @@ default `opts` values:
         }
         return stat.isDirectory();
     },
+    defaultUnwrapSymlink: function unwrapSymlink(file) {
+        try {
+            return fs.realpathSync(file);
+        } catch (realPathErr) {
+            if (realPathErr.code !== 'ENOENT') {
+                throw realPathErr;
+            }
+        }
+        return file;
+    },
     moduleDirectory: 'node_modules',
     preserveSymlinks: false
 }
diff --git a/test/mock.js b/test/mock.js
@@ -22,6 +22,9 @@ test('mock', function (t) {
             },
             readFile: function (file, cb) {
                 cb(null, files[path.resolve(file)]);
+            },
+            unwrapSymlink: function (file, cb) {
+                cb(null, file);
             }
         };
     }
@@ -70,6 +73,9 @@ test('mock from package', function (t) {
             'package': { main: 'bar' },
             readFile: function (file, cb) {
                 cb(null, files[file]);
+            },
+            unwrapSymlink: function (file, cb) {
+                cb(null, file);
             }
         };
     }
@@ -121,6 +127,9 @@ test('mock package', function (t) {
             },
             readFile: function (file, cb) {
                 cb(null, files[path.resolve(file)]);
+            },
+            unwrapSymlink: function (file, cb) {
+                cb(null, file);
             }
         };
     }
@@ -157,6 +166,9 @@ test('mock package from package', function (t) {
             'package': { main: 'bar' },
             readFile: function (file, cb) {
                 cb(null, files[path.resolve(file)]);
+            },
+            unwrapSymlink: function (file, cb) {
+                cb(null, file);
             }
         };
     }
diff --git a/test/mock_sync.js b/test/mock_sync.js
@@ -23,6 +23,9 @@ test('mock', function (t) {
             },
             readFileSync: function (file) {
                 return files[path.resolve(file)];
+            },
+            unwrapSymlink: function (file) {
+                return file;
             }
         };
     }
@@ -70,6 +73,9 @@ test('mock package', function (t) {
             },
             readFileSync: function (file) {
                 return files[path.resolve(file)];
+            },
+            unwrapSymlink: function (file) {
+                return file;
             }
         };
     }

Original file line number	Diff line number	Diff line change
`@@ -22,6 +22,9 @@ test('mock', function (t) {`
`22`	`22`	`},`
`23`	`23`	`readFile: function (file, cb) {`
`24`	`24`	`cb(null, files[path.resolve(file)]);`
	`25`	`+ },`
	`26`	`+ unwrapSymlink: function (file, cb) {`
	`27`	`+ cb(null, file);`
`25`	`28`	`}`
`26`	`29`	`};`
`27`	`30`	`}`
`@@ -70,6 +73,9 @@ test('mock from package', function (t) {`
`70`	`73`	`'package': { main: 'bar' },`
`71`	`74`	`readFile: function (file, cb) {`
`72`	`75`	`cb(null, files[file]);`
	`76`	`+ },`
	`77`	`+ unwrapSymlink: function (file, cb) {`
	`78`	`+ cb(null, file);`
`73`	`79`	`}`
`74`	`80`	`};`
`75`	`81`	`}`
`@@ -121,6 +127,9 @@ test('mock package', function (t) {`
`121`	`127`	`},`
`122`	`128`	`readFile: function (file, cb) {`
`123`	`129`	`cb(null, files[path.resolve(file)]);`
	`130`	`+ },`
	`131`	`+ unwrapSymlink: function (file, cb) {`
	`132`	`+ cb(null, file);`
`124`	`133`	`}`
`125`	`134`	`};`
`126`	`135`	`}`
`@@ -157,6 +166,9 @@ test('mock package from package', function (t) {`
`157`	`166`	`'package': { main: 'bar' },`
`158`	`167`	`readFile: function (file, cb) {`
`159`	`168`	`cb(null, files[path.resolve(file)]);`
	`169`	`+ },`
	`170`	`+ unwrapSymlink: function (file, cb) {`
	`171`	`+ cb(null, file);`
`160`	`172`	`}`
`161`	`173`	`};`
`162`	`174`	`}`
Original file line number	Diff line number	Diff line change
`@@ -23,6 +23,9 @@ test('mock', function (t) {`
`23`	`23`	`},`
`24`	`24`	`readFileSync: function (file) {`
`25`	`25`	`return files[path.resolve(file)];`
	`26`	`+ },`
	`27`	`+ unwrapSymlink: function (file) {`
	`28`	`+ return file;`
`26`	`29`	`}`
`27`	`30`	`};`
`28`	`31`	`}`
`@@ -70,6 +73,9 @@ test('mock package', function (t) {`
`70`	`73`	`},`
`71`	`74`	`readFileSync: function (file) {`
`72`	`75`	`return files[path.resolve(file)];`
	`76`	`+ },`
	`77`	`+ unwrapSymlink: function (file) {`
	`78`	`+ return file;`
`73`	`79`	`}`
`74`	`80`	`};`
`75`	`81`	`}`