Make AutoImportProviderProject work with symlinked monorepos

src/compiler/checker.ts

@@ -4234,7 +4234,7 @@ namespace ts {
                         getCommonSourceDirectory: !!(host as Program).getCommonSourceDirectory ? () => (host as Program).getCommonSourceDirectory() : () => "",
                         getSourceFiles: () => host.getSourceFiles(),
                         getCurrentDirectory: () => host.getCurrentDirectory(),
-                        getProbableSymlinks: maybeBind(host, host.getProbableSymlinks),
+                        getSymlinkCache: maybeBind(host, host.getSymlinkCache),
                         useCaseSensitiveFileNames: maybeBind(host, host.useCaseSensitiveFileNames),
                         redirectTargetsMap: host.redirectTargetsMap,
                         getProjectReferenceRedirect: fileName => host.getProjectReferenceRedirect(fileName),

src/compiler/moduleSpecifiers.ts

@@ -185,20 +185,22 @@ namespace ts.moduleSpecifiers {
             const result = forEach(targets, cb);
             if (result) return result;
         }
-        const links = host.getProbableSymlinks
-            ? host.getProbableSymlinks(host.getSourceFiles())
+        const links = host.getSymlinkCache
+            ? host.getSymlinkCache()
             : discoverProbableSymlinks(host.getSourceFiles(), getCanonicalFileName, cwd);
 
+        const symlinkedDirectories = links.getSymlinkedDirectories();
         const compareStrings = (!host.useCaseSensitiveFileNames || host.useCaseSensitiveFileNames()) ? compareStringsCaseSensitive : compareStringsCaseInsensitive;
-        const result = forEachEntry(links, (resolved, path) => {
-            if (startsWithDirectory(importingFileName, resolved, getCanonicalFileName)) {
+        const result = symlinkedDirectories && forEachEntry(symlinkedDirectories, (resolved, path) => {
+            if (resolved === false) return;
+            if (startsWithDirectory(importingFileName, resolved.realPath, getCanonicalFileName)) {
                 return undefined; // Don't want to a package to globally import from itself
             }
 
-            const target = find(targets, t => compareStrings(t.slice(0, resolved.length + 1), resolved + "/") === Comparison.EqualTo);
+            const target = find(targets, t => compareStrings(t.slice(0, resolved.real.length), resolved.real) === Comparison.EqualTo);
             if (target === undefined) return undefined;
 
-            const relative = getRelativePathFromDirectory(resolved, target, getCanonicalFileName);
+            const relative = getRelativePathFromDirectory(resolved.real, target, getCanonicalFileName);
             const option = resolvePath(path, relative);
             if (!host.fileExists || host.fileExists(option)) {
                 const result = cb(option);

src/compiler/program.ts

@@ -702,7 +702,7 @@ namespace ts {
         let processingDefaultLibFiles: SourceFile[] | undefined;
         let processingOtherFiles: SourceFile[] | undefined;
         let files: SourceFile[];
-        let symlinks: ReadonlyESMap<string, string> | undefined;
+        let symlinks: SymlinkCache | undefined;
         let commonSourceDirectory: string;
         let diagnosticsProducingTypeChecker: TypeChecker;
         let noDiagnosticsTypeChecker: TypeChecker;
@@ -811,8 +811,9 @@ namespace ts {
 
         const useSourceOfProjectReferenceRedirect = !!host.useSourceOfProjectReferenceRedirect?.() &&
             !options.disableSourceOfProjectReferenceRedirect;
-        const { onProgramCreateComplete, fileExists } = updateHostForUseSourceOfProjectReferenceRedirect({
+        const { onProgramCreateComplete, fileExists, directoryExists } = updateHostForUseSourceOfProjectReferenceRedirect({
             compilerHost: host,
+            getSymlinkCache,
             useSourceOfProjectReferenceRedirect,
             toPath,
             getResolvedProjectReferences,
@@ -974,7 +975,8 @@ namespace ts {
             isSourceOfProjectReferenceRedirect,
             emitBuildInfo,
             fileExists,
-            getProbableSymlinks,
+            directoryExists,
+            getSymlinkCache,
             useCaseSensitiveFileNames: () => host.useCaseSensitiveFileNames(),
         };
 
@@ -1490,7 +1492,7 @@ namespace ts {
                 getResolvedProjectReferenceToRedirect,
                 getProjectReferenceRedirect,
                 isSourceOfProjectReferenceRedirect,
-                getProbableSymlinks,
+                getSymlinkCache,
                 writeFile: writeFileCallback || (
                     (fileName, data, writeByteOrderMark, onError, sourceFiles) => host.writeFile(fileName, data, writeByteOrderMark, onError, sourceFiles)),
                 isEmitBlocked,
@@ -3468,9 +3470,9 @@ namespace ts {
             return comparePaths(file1, file2, currentDirectory, !host.useCaseSensitiveFileNames()) === Comparison.EqualTo;
         }
 
-        function getProbableSymlinks(): ReadonlyESMap<string, string> {
-            if (host.getSymlinks) {
-                return host.getSymlinks();
+        function getSymlinkCache(): SymlinkCache {
+            if (host.getSymlinkCache) {
+                return host.getSymlinkCache();
             }
             return symlinks || (symlinks = discoverProbableSymlinks(
                 files,
@@ -3479,13 +3481,9 @@ namespace ts {
         }
     }
 
-    interface SymlinkedDirectory {
-        real: string;
-        realPath: Path;
-    }
-
     interface HostForUseSourceOfProjectReferenceRedirect {
         compilerHost: CompilerHost;
+        getSymlinkCache: () => SymlinkCache;
         useSourceOfProjectReferenceRedirect: boolean;
         toPath(fileName: string): Path;
         getResolvedProjectReferences(): readonly (ResolvedProjectReference | undefined)[] | undefined;
@@ -3495,9 +3493,6 @@ namespace ts {
 
     function updateHostForUseSourceOfProjectReferenceRedirect(host: HostForUseSourceOfProjectReferenceRedirect) {
         let setOfDeclarationDirectories: Set<Path> | undefined;
-        let symlinkedDirectories: ESMap<Path, SymlinkedDirectory | false> | undefined;
-        let symlinkedFiles: ESMap<Path, string> | undefined;
-
         const originalFileExists = host.compilerHost.fileExists;
         const originalDirectoryExists = host.compilerHost.directoryExists;
         const originalGetDirectories = host.compilerHost.getDirectories;
@@ -3507,11 +3502,12 @@ namespace ts {
 
         host.compilerHost.fileExists = fileExists;
 
+        let directoryExists;
         if (originalDirectoryExists) {
             // This implementation of directoryExists checks if the directory being requested is
             // directory of .d.ts file for the referenced Project.
             // If it is it returns true irrespective of whether that directory exists on host
-            host.compilerHost.directoryExists = path => {
+            directoryExists = host.compilerHost.directoryExists = path => {
                 if (originalDirectoryExists.call(host.compilerHost, path)) {
                     handleDirectoryCouldBeSymlink(path);
                     return true;
@@ -3553,11 +3549,11 @@ namespace ts {
         // This is something we keep for life time of the host
         if (originalRealpath) {
             host.compilerHost.realpath = s =>
-                symlinkedFiles?.get(host.toPath(s)) ||
+                host.getSymlinkCache().getSymlinkedFiles()?.get(host.toPath(s)) ||
                 originalRealpath.call(host.compilerHost, s);
         }
 
-        return { onProgramCreateComplete, fileExists };
+        return { onProgramCreateComplete, fileExists, directoryExists };
 
         function onProgramCreateComplete() {
             host.compilerHost.fileExists = originalFileExists;
@@ -3603,20 +3599,20 @@ namespace ts {
 
             // Because we already watch node_modules, handle symlinks in there
             if (!originalRealpath || !stringContains(directory, nodeModulesPathPart)) return;
-            if (!symlinkedDirectories) symlinkedDirectories = new Map();
+            const symlinkCache = host.getSymlinkCache();
             const directoryPath = ensureTrailingDirectorySeparator(host.toPath(directory));
-            if (symlinkedDirectories.has(directoryPath)) return;
+            if (symlinkCache.getSymlinkedDirectories()?.has(directoryPath)) return;
 
             const real = normalizePath(originalRealpath.call(host.compilerHost, directory));
             let realPath: Path;
             if (real === directory ||
                 (realPath = ensureTrailingDirectorySeparator(host.toPath(real))) === directoryPath) {
                 // not symlinked
-                symlinkedDirectories.set(directoryPath, false);
+                symlinkCache.setSymlinkedDirectory(directoryPath, false);
                 return;
             }
 
-            symlinkedDirectories.set(directoryPath, {
+            symlinkCache.setSymlinkedDirectory(directoryPath, {
                 real: ensureTrailingDirectorySeparator(real),
                 realPath
             });
@@ -3630,10 +3626,12 @@ namespace ts {
             const result = fileOrDirectoryExistsUsingSource(fileOrDirectory);
             if (result !== undefined) return result;
 
+            const symlinkCache = host.getSymlinkCache();
+            const symlinkedDirectories = symlinkCache.getSymlinkedDirectories();
             if (!symlinkedDirectories) return false;
             const fileOrDirectoryPath = host.toPath(fileOrDirectory);
             if (!stringContains(fileOrDirectoryPath, nodeModulesPathPart)) return false;
-            if (isFile && symlinkedFiles && symlinkedFiles.has(fileOrDirectoryPath)) return true;
+            if (isFile && symlinkCache.getSymlinkedFiles()?.has(fileOrDirectoryPath)) return true;
 
             // If it contains node_modules check if its one of the symlinked path we know of
             return firstDefinedIterator(
@@ -3642,10 +3640,9 @@ namespace ts {
                     if (!symlinkedDirectory || !startsWith(fileOrDirectoryPath, directoryPath)) return undefined;
                     const result = fileOrDirectoryExistsUsingSource(fileOrDirectoryPath.replace(directoryPath, symlinkedDirectory.realPath));
                     if (isFile && result) {
-                        if (!symlinkedFiles) symlinkedFiles = new Map();
                         // Store the real path for the file'
                         const absolutePath = getNormalizedAbsolutePath(fileOrDirectory, host.compilerHost.getCurrentDirectory());
-                        symlinkedFiles.set(
+                        symlinkCache.setSymlinkedFile(
                             fileOrDirectoryPath,
                             `${symlinkedDirectory.real}${absolutePath.replace(new RegExp(directoryPath, "i"), "")}`
                         );

src/compiler/types.ts

@@ -3767,7 +3767,6 @@ namespace ts {
         /*@internal*/ isSourceOfProjectReferenceRedirect(fileName: string): boolean;
         /*@internal*/ getProgramBuildInfo?(): ProgramBuildInfo | undefined;
         /*@internal*/ emitBuildInfo(writeFile?: WriteFileCallback, cancellationToken?: CancellationToken): EmitResult;
-        /*@internal*/ getProbableSymlinks(): ReadonlyESMap<string, string>;
         /**
          * This implementation handles file exists to be true if file is source of project reference redirect when program is created using useSourceOfProjectReferenceRedirect
          */
@@ -6240,7 +6239,7 @@ namespace ts {
 
         // TODO: later handle this in better way in builder host instead once the api for tsbuild finalizes and doesn't use compilerHost as base
         /*@internal*/createDirectory?(directory: string): void;
-        /*@internal*/getSymlinks?(): ReadonlyESMap<string, string>;
+        /*@internal*/getSymlinkCache?(): SymlinkCache;
     }
 
     /** true if --out otherwise source file name */
@@ -7754,8 +7753,9 @@ namespace ts {
         useCaseSensitiveFileNames?(): boolean;
         fileExists(path: string): boolean;
         getCurrentDirectory(): string;
+        directoryExists?(path: string): boolean;
         readFile?(path: string): string | undefined;
-        getProbableSymlinks?(files: readonly SourceFile[]): ReadonlyESMap<string, string>;
+        getSymlinkCache?(): SymlinkCache;
         getGlobalTypingsCacheLocation?(): string | undefined;
 
         getSourceFiles(): readonly SourceFile[];

src/compiler/utilities.ts

@@ -5926,28 +5926,57 @@ namespace ts {
         return true;
     }
 
-    export function discoverProbableSymlinks(files: readonly SourceFile[], getCanonicalFileName: GetCanonicalFileName, cwd: string): ReadonlyESMap<string, string> {
-        const result = new Map<string, string>();
+    export interface SymlinkedDirectory {
+        real: string;
+        realPath: Path;
+    }
+
+    export interface SymlinkCache {
+        getSymlinkedDirectories(): ReadonlyESMap<Path, SymlinkedDirectory | false> | undefined;
+        getSymlinkedFiles(): ReadonlyESMap<Path, string> | undefined;
+        setSymlinkedDirectory(path: Path, directory: SymlinkedDirectory | false): void;
+        setSymlinkedFile(path: Path, real: string): void;
+    }
+
+    export function createSymlinkCache(): SymlinkCache {
+        let symlinkedDirectories: ESMap<Path, SymlinkedDirectory | false> | undefined;
+        let symlinkedFiles: ESMap<Path, string> | undefined;
+        return {
+            getSymlinkedFiles: () => symlinkedFiles,
+            getSymlinkedDirectories: () => symlinkedDirectories,
+            setSymlinkedFile: (path, real) => (symlinkedFiles || (symlinkedFiles = new Map())).set(path, real),
+            setSymlinkedDirectory: (path, directory) => (symlinkedDirectories || (symlinkedDirectories = new Map())).set(path, directory),
+        };
+    }
+
+    export function discoverProbableSymlinks(files: readonly SourceFile[], getCanonicalFileName: GetCanonicalFileName, cwd: string): SymlinkCache {
+        const cache = createSymlinkCache();
         const symlinks = flatten<readonly [string, string]>(mapDefined(files, sf =>
             sf.resolvedModules && compact(arrayFrom(mapIterator(sf.resolvedModules.values(), res =>
                 res && res.originalPath && res.resolvedFileName !== res.originalPath ? [res.resolvedFileName, res.originalPath] as const : undefined)))));
         for (const [resolvedPath, originalPath] of symlinks) {
-            const [commonResolved, commonOriginal] = guessDirectorySymlink(resolvedPath, originalPath, cwd, getCanonicalFileName);
-            result.set(commonOriginal, commonResolved);
+            const [commonResolved, commonOriginal] = guessDirectorySymlink(resolvedPath, originalPath, cwd, getCanonicalFileName) || emptyArray;
+            if (commonResolved && commonOriginal) {
+                cache.setSymlinkedDirectory(
+                    toPath(commonOriginal, cwd, getCanonicalFileName),
+                    { real: commonResolved, realPath: toPath(commonResolved, cwd, getCanonicalFileName) });
+            }
         }
-        return result;
+        return cache;
     }
 
-    function guessDirectorySymlink(a: string, b: string, cwd: string, getCanonicalFileName: GetCanonicalFileName): [string, string] {
+    function guessDirectorySymlink(a: string, b: string, cwd: string, getCanonicalFileName: GetCanonicalFileName): [string, string] | undefined {
         const aParts = getPathComponents(toPath(a, cwd, getCanonicalFileName));
         const bParts = getPathComponents(toPath(b, cwd, getCanonicalFileName));
+        let isDirectory = false;
         while (!isNodeModulesOrScopedPackageDirectory(aParts[aParts.length - 2], getCanonicalFileName) &&
             !isNodeModulesOrScopedPackageDirectory(bParts[bParts.length - 2], getCanonicalFileName) &&
             getCanonicalFileName(aParts[aParts.length - 1]) === getCanonicalFileName(bParts[bParts.length - 1])) {
             aParts.pop();
             bParts.pop();
+            isDirectory = true;
         }
-        return [getPathFromPathComponents(aParts), getPathFromPathComponents(bParts)];
+        return isDirectory ? [getPathFromPathComponents(aParts), getPathFromPathComponents(bParts)] : undefined;
     }
 
     // KLUDGE: Don't assume one 'node_modules' links to another. More likely a single directory inside the node_modules is the symlink.

src/harness/harnessLanguageService.ts

@@ -154,6 +154,19 @@ namespace Harness.LanguageService {
             return fileNames;
         }
 
+        public realpath(path: string): string {
+            try {
+                return this.vfs.realpathSync(path);
+            }
+            catch {
+                return path;
+            }
+        }
+
+        public directoryExists(path: string) {
+            return this.vfs.statSync(path).isDirectory();
+        }
+
         public getScriptInfo(fileName: string): ScriptInfo | undefined {
             return this.scriptInfos.get(vpath.resolve(this.vfs.cwd(), fileName));
         }
@@ -720,18 +733,23 @@ namespace Harness.LanguageService {
                 fileName = Compiler.defaultLibFileName;
             }
 
-            const snapshot = this.host.getScriptSnapshot(fileName);
+            // System FS would follow symlinks, even though snapshots are stored by original file name
+            const snapshot = this.host.getScriptSnapshot(fileName) || this.host.getScriptSnapshot(this.realpath(fileName));
             return snapshot && ts.getSnapshotText(snapshot);
         }
 
+        realpath(path: string) {
+            return this.host.realpath(path);
+        }
+
         writeFile = ts.noop;
 
         resolvePath(path: string): string {
             return path;
         }
 
         fileExists(path: string): boolean {
-            return !!this.host.getScriptSnapshot(path);
+            return this.host.fileExists(path);
         }
 
         directoryExists(): boolean {