Refactor to create a new FileUtils method

Author: zaggino

src/file/FileUtils.js

@@ -34,6 +34,7 @@ define(function (require, exports, module) {
     require("utils/Global");
 
     var FileSystemError     = require("filesystem/FileSystemError"),
+        LanguageManager     = require("language/LanguageManager"),
         PerfUtils           = require("utils/PerfUtils"),
         Dialogs             = require("widgets/Dialogs"),
         DefaultDialogs      = require("widgets/DefaultDialogs"),
@@ -309,6 +310,41 @@ define(function (require, exports, module) {
         return baseName.substr(idx + 1);
     }
 
+    /**
+     * Get the file extension (excluding ".") given a path OR a bare filename.
+     * Returns "" for names with no extension.
+     * If the only `.` in the file is the first character,
+     * returns "" as this is not considered an extension.
+     * This method considers known extensions which include `.` in them.
+     *
+     * @param {string} fullPath full path to a file or directory
+     * @return {string} Returns the extension of a filename or empty string if
+     * the argument is a directory or a filename with no extension
+     */
+    function getSmartFileExtension(fullPath) {
+        var baseName = getBaseName(fullPath),
+            parts = baseName.split(".");
+
+        // get rid of file name
+        parts.shift();
+        if (baseName[0] === ".") {
+            // if starts with a `.`, then still consider it as file name
+            parts.shift();
+        }
+
+        // test all other parts of the baseName
+        while (parts.length > 1) {
+            var ext = parts.join(".");
+            if (LanguageManager.getLanguageForExtension(ext)) {
+                return ext;
+            } else {
+                parts.shift();
+            }
+        }
+
+        return parts[0] || "";
+    }
+
     /**
      * Computes filename as relative to the basePath. For example:
      * basePath: /foo/bar/, filename: /foo/bar/baz.txt
@@ -426,5 +462,6 @@ define(function (require, exports, module) {
     exports.getBaseName                    = getBaseName;
     exports.getRelativeFilename            = getRelativeFilename;
     exports.getFileExtension               = getFileExtension;
+    exports.getSmartFileExtension          = getSmartFileExtension;
     exports.compareFilenames               = compareFilenames;
 });

src/language/LanguageManager.js

@@ -196,6 +196,15 @@ define(function (require, exports, module) {
         return _languages[id];
     }
 
+    /**
+     * Resolves a language to a file extension
+     * @param {!string} extension Extension that language should be resolved for
+     * @return {?Language} The language for the provided extension or null if none exists
+     */
+    function getLanguageForExtension(extension) {
+        return _fileExtensionToLanguageMap[extension.toLowerCase()];
+    }
+
     /**
      * Resolves a file path to a Language object.
      * @param {!string} path Path to the file to find a language for
@@ -804,5 +813,6 @@ define(function (require, exports, module) {
     exports.ready                   = _ready;
     exports.defineLanguage          = defineLanguage;
     exports.getLanguage             = getLanguage;
+    exports.getLanguageForExtension = getLanguageForExtension;
     exports.getLanguageForPath      = getLanguageForPath;
 });

src/project/ProjectManager.js

@@ -1811,22 +1811,12 @@ define(function (require, exports, module) {
                 _projectTree.jstree("set_text", $selected, escapedName);
                 _projectTree.jstree("rename");
 
-                var indexOfExtension = escapedName.lastIndexOf("."),
-                    language = LanguageManager.getLanguageForPath(entry.name);
-                if (language) {
-                    language.getFileExtensions().forEach(function (ext) {
-                        ext = "." + ext;
-                        if (escapedName.match(ext + "$")) {
-                            var io = escapedName.lastIndexOf(ext);
-                            if (io < indexOfExtension) {
-                                indexOfExtension = io;
-                            }
-                        }
-                    });
-                }
-
-                if (indexOfExtension > 0) {
-                    $selected.children(".jstree-rename-input")[0].setSelectionRange(0, indexOfExtension);
+                var extension = FileUtils.getSmartFileExtension(entry.name);
+                if (extension) {
+                    var indexOfExtension = escapedName.length - extension.length - 1;
+                    if (indexOfExtension > 0) {
+                        $selected.children(".jstree-rename-input")[0].setSelectionRange(0, indexOfExtension);
+                    }
                 }
             });
         // No fail handler: silently no-op if file doesn't exist in tree

test/spec/FileUtils-test.js

@@ -125,5 +125,39 @@ define(function (require, exports, module) {
                 expect(FileUtils.getFileExtension("foo.bar.baz..jaz.txt")).toBe("txt");
             });
         });
+
+        describe("getSmartFileExtension", function () {
+
+            it("should get the extension of a normalized win file path", function () {
+                expect(FileUtils.getSmartFileExtension("C:/foo/bar/baz.txt")).toBe("txt");
+            });
+
+            it("should get the extension of a posix file path", function () {
+                expect(FileUtils.getSmartFileExtension("/foo/bar/baz.txt")).toBe("txt");
+            });
+
+            it("should return empty extension for a normalized win directory path", function () {
+                expect(FileUtils.getSmartFileExtension("C:/foo/bar/")).toBe("");
+            });
+
+            it("should return empty extension for a posix directory path", function () {
+                expect(FileUtils.getSmartFileExtension("bar")).toBe("");
+            });
+
+            it("should return the extension of a filename containing .", function () {
+                expect(FileUtils.getSmartFileExtension("C:/foo/bar/.baz/jaz.txt")).toBe("txt");
+                expect(FileUtils.getSmartFileExtension("foo/bar/baz/.jaz.txt")).toBe("txt");
+                expect(FileUtils.getSmartFileExtension("foo.bar.baz..jaz.txt")).toBe("txt");
+            });
+
+            it("should return no extension for files with only . as a first character", function () {
+                expect(FileUtils.getSmartFileExtension("C:/foo/bar/.baz/.jaz")).toBe("");
+            });
+
+            it("should return the extension containing . for known types", function () {
+                expect(FileUtils.getSmartFileExtension("C:/foo/bar/.baz/jaz.scss.erb")).toBe("scss.erb");
+                expect(FileUtils.getSmartFileExtension("foo/bar/baz/.jaz.js.erb")).toBe("js.erb");
+            });
+        });
     });
 });