Do not watch folders like "c:/users/username", "c:/users/username/folderAtRoot"

sheetalkamat · sheetalkamat · commit 16e01174b70d · 2018-06-07T13:52:34.000-07:00
Fixes microsoft/vscode#51139
diff --git a/src/compiler/resolutionCache.ts b/src/compiler/resolutionCache.ts
@@ -349,8 +349,32 @@ namespace ts {
             return endsWith(dirPath, "/node_modules/@types");
         }
 
-        function isDirectoryAtleastAtLevelFromFSRoot(dirPath: Path, minLevels: number) {
-            for (let searchIndex = getRootLength(dirPath); minLevels > 0; minLevels--) {
+        /**
+         * Filter out paths like
+         * "/", "/user", "/user/username", "/user/username/folderAtRoot",
+         * "c:/", "c:/users", "c:/users/username", "c:/users/username/folderAtRoot", "c:/folderAtRoot"
+         * @param dirPath
+         */
+        function canWatchDirectory(dirPath: Path) {
+            const rootLength = getRootLength(dirPath);
+            if (dirPath.length === rootLength) {
+                // Ignore "/", "c:/"
+                return false;
+            }
+
+            const nextDirectorySeparator = dirPath.indexOf(directorySeparator, rootLength);
+            if (nextDirectorySeparator === -1) {
+                // ignore "/user", "c:/users" or "c:/folderAtRoot"
+                return false;
+            }
+
+            if (dirPath.charCodeAt(0) !== CharacterCodes.slash &&
+                dirPath.substr(rootLength, nextDirectorySeparator).search(/users/i) === -1) {
+                // Paths like c:/folderAtRoot/subFolder are allowed
+                return true;
+            }
+
+            for (let searchIndex = nextDirectorySeparator + 1, searchLevels = 2; searchLevels > 0; searchLevels--) {
                 searchIndex = dirPath.indexOf(directorySeparator, searchIndex) + 1;
                 if (searchIndex === 0) {
                     // Folder isnt at expected minimun levels
@@ -360,15 +384,6 @@ namespace ts {
             return true;
         }
 
-        function canWatchDirectory(dirPath: Path) {
-            return isDirectoryAtleastAtLevelFromFSRoot(dirPath,
-                // When root is "/" do not watch directories like:
-                // "/", "/user", "/user/username", "/user/username/folderAtRoot"
-                // When root is "c:/" do not watch directories like:
-                // "c:/", "c:/folderAtRoot"
-                dirPath.charCodeAt(0) === CharacterCodes.slash ? 3 : 1);
-        }
-
         function filterFSRootDirectoriesToWatch(watchPath: DirectoryOfFailedLookupWatch, dirPath: Path): DirectoryOfFailedLookupWatch {
             if (!canWatchDirectory(dirPath)) {
                 watchPath.ignore = true;
diff --git a/src/harness/unittests/tsserverProjectSystem.ts b/src/harness/unittests/tsserverProjectSystem.ts
@@ -7501,8 +7501,8 @@ namespace ts.projectSystem {
     });
 
     describe("tsserverProjectSystem Watched recursive directories with windows style file system", () => {
-        function verifyWatchedDirectories(useProjectAtRoot: boolean) {
-            const root = useProjectAtRoot ? "c:/" : "c:/myfolder/allproject/";
+        function verifyWatchedDirectories(rootedPath: string, useProjectAtRoot: boolean) {
+            const root = useProjectAtRoot ? rootedPath : `${rootedPath}myfolder/allproject/`;
             const configFile: File = {
                 path: root + "project/tsconfig.json",
                 content: "{}"
@@ -7531,12 +7531,22 @@ namespace ts.projectSystem {
             ].concat(useProjectAtRoot ? [] : [root + nodeModulesAtTypes]), /*recursive*/ true);
         }
 
-        it("When project is in rootFolder", () => {
-            verifyWatchedDirectories(/*useProjectAtRoot*/ true);
+        function verifyRootedDirectoryWatch(rootedPath: string) {
+            it("When project is in rootFolder of style c:/", () => {
+                verifyWatchedDirectories(rootedPath, /*useProjectAtRoot*/ true);
+            });
+
+            it("When files at some folder other than root", () => {
+                verifyWatchedDirectories(rootedPath, /*useProjectAtRoot*/ false);
+            });
+        }
+
+        describe("for rootFolder of style c:/", () => {
+            verifyRootedDirectoryWatch("c:/");
         });
 
-        it("When files at some folder other than root", () => {
-            verifyWatchedDirectories(/*useProjectAtRoot*/ false);
+        describe("for rootFolder of style c:/users/username", () => {
+            verifyRootedDirectoryWatch("c:/users/username/");
         });
     });
 
