feat: add Yarn PnP support

src/compiler/moduleNameResolver.ts

@@ -267,22 +267,22 @@ namespace ts {
 
     /**
      * Returns the path to every node_modules/@types directory from some ancestor directory.
-     * Returns undefined if there are none.
      */
-    function getDefaultTypeRoots(currentDirectory: string, host: { directoryExists?: (directoryName: string) => boolean }): string[] | undefined {
+    function getNodeModulesTypeRoots(currentDirectory: string, host: { directoryExists?: (directoryName: string) => boolean }) {
         if (!host.directoryExists) {
             return [combinePaths(currentDirectory, nodeModulesAtTypes)];
             // And if it doesn't exist, tough.
         }
 
-        let typeRoots: string[] | undefined;
+        const typeRoots: string[] = [];
         forEachAncestorDirectory(normalizePath(currentDirectory), directory => {
             const atTypes = combinePaths(directory, nodeModulesAtTypes);
             if (host.directoryExists!(atTypes)) {
-                (typeRoots || (typeRoots = [])).push(atTypes);
+                typeRoots.push(atTypes);
             }
             return undefined;
         });
+
         return typeRoots;
     }
     const nodeModulesAtTypes = combinePaths("node_modules", "@types");
@@ -292,6 +292,50 @@ namespace ts {
         return comparePaths(path1, path2, !useCaseSensitiveFileNames) === Comparison.EqualTo;
     }
 
+    /**
+     * @internal
+     */
+    export function getPnpTypeRoots(currentDirectory: string) {
+        const pnpapi = getPnpApi(currentDirectory);
+        if (!pnpapi) {
+            return [];
+        }
+
+        // Some TS consumers pass relative paths that aren't normalized
+        currentDirectory = sys.resolvePath(currentDirectory);
+
+        const currentPackage = pnpapi.findPackageLocator(`${currentDirectory}/`);
+        if (!currentPackage) {
+            return [];
+        }
+
+        const {packageDependencies} = pnpapi.getPackageInformation(currentPackage);
+
+        const typeRoots: string[] = [];
+        for (const [name, referencish] of Array.from<any>(packageDependencies.entries())) {
+            // eslint-disable-next-line no-null/no-null
+            if (name.startsWith(typesPackagePrefix) && referencish !== null) {
+                const dependencyLocator = pnpapi.getLocator(name, referencish);
+                const {packageLocation} = pnpapi.getPackageInformation(dependencyLocator);
+
+                typeRoots.push(getDirectoryPath(packageLocation));
+            }
+        }
+
+        return typeRoots;
+    }
+
+    const typesPackagePrefix = "@types/";
+
+    function getDefaultTypeRoots(currentDirectory: string, host: { directoryExists?: (directoryName: string) => boolean }): string[] | undefined {
+        const nmTypes = getNodeModulesTypeRoots(currentDirectory, host);
+        const pnpTypes = getPnpTypeRoots(currentDirectory);
+
+        if (nmTypes.length > 0 || pnpTypes.length > 0) {
+            return [...nmTypes, ...pnpTypes];
+        }
+    }
+
     /**
      * @param {string | undefined} containingFile - file that contains type reference directive, can be undefined if containing file is unknown.
      * This is possible in case if resolution is performed for directives specified via 'types' parameter. In this case initial path for secondary lookups
@@ -425,7 +469,10 @@ namespace ts {
                 }
                 let result: Resolved | undefined;
                 if (!isExternalModuleNameRelative(typeReferenceDirectiveName)) {
-                    const searchResult = loadModuleFromNearestNodeModulesDirectory(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, moduleResolutionState, /*cache*/ undefined, /*redirectedReference*/ undefined);
+                    const searchResult = getPnpApi(initialLocationForSecondaryLookup)
+                        ? tryLoadModuleUsingPnpResolution(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, moduleResolutionState, /*cache*/ undefined, /*redirectedReference*/ undefined)
+                        : loadModuleFromNearestNodeModulesDirectory(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, moduleResolutionState, /*cache*/ undefined, /*redirectedReference*/ undefined);
+
                     result = searchResult && searchResult.value;
                 }
                 else {
@@ -1331,7 +1378,9 @@ namespace ts {
                     if (traceEnabled) {
                         trace(host, Diagnostics.Loading_module_0_from_node_modules_folder_target_file_type_1, moduleName, Extensions[extensions]);
                     }
-                    resolved = loadModuleFromNearestNodeModulesDirectory(extensions, moduleName, containingDirectory, state, cache, redirectedReference);
+                    resolved = getPnpApi(containingDirectory)
+                        ? tryLoadModuleUsingPnpResolution(extensions, moduleName, containingDirectory, state, cache, redirectedReference)
+                        : loadModuleFromNearestNodeModulesDirectory(extensions, moduleName, containingDirectory, state, cache, redirectedReference);
                 }
                 if (!resolved) return undefined;
 
@@ -2191,7 +2240,15 @@ namespace ts {
 
     function loadModuleFromSpecificNodeModulesDirectory(extensions: Extensions, moduleName: string, nodeModulesDirectory: string, nodeModulesDirectoryExists: boolean, state: ModuleResolutionState, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined): Resolved | undefined {
         const candidate = normalizePath(combinePaths(nodeModulesDirectory, moduleName));
+        return loadModuleFromSpecificNodeModulesDirectoryImpl(extensions, moduleName, nodeModulesDirectory, nodeModulesDirectoryExists, state, cache, redirectedReference, candidate, /* rest */ undefined, /* packageDirectory */ undefined);
+    }
 
+    function loadModuleFromPnpResolution(extensions: Extensions, packageDirectory: string, rest: string, state: ModuleResolutionState, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined): Resolved | undefined {
+        const candidate = normalizePath(combinePaths(packageDirectory, rest));
+        return loadModuleFromSpecificNodeModulesDirectoryImpl(extensions, /*moduleName*/ undefined, /*nodeModulesDirectory*/ undefined, /*nodeModulesDirectoryExists*/ true, state, cache, redirectedReference, candidate, rest, packageDirectory);
+    }
+
+    function loadModuleFromSpecificNodeModulesDirectoryImpl(extensions: Extensions, moduleName: string | undefined, nodeModulesDirectory: string | undefined, nodeModulesDirectoryExists: boolean, state: ModuleResolutionState, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined, candidate: string, rest: string | undefined, packageDirectory: string | undefined): Resolved | undefined {
         // First look for a nested package.json, as in `node_modules/foo/bar/package.json`.
         let packageInfo = getPackageJsonInfo(candidate, !nodeModulesDirectoryExists, state);
         // But only if we're not respecting export maps (if we are, we might redirect around this location)
@@ -2214,7 +2271,8 @@ namespace ts {
             }
         }
 
-        const { packageName, rest } = parsePackageName(moduleName);
+        let packageName: string;
+        if (rest === undefined) ({ packageName, rest } = parsePackageName(moduleName!));
         const loader: ResolutionKindSpecificLoader = (extensions, candidate, onlyRecordFailures, state) => {
             // package exports are higher priority than file/directory lookups (and, if there's exports present, blocks them)
             if (packageInfo && packageInfo.packageJsonContent.exports && state.features & NodeResolutionFeatures.Exports) {
@@ -2244,7 +2302,7 @@ namespace ts {
         };
 
         if (rest !== "") { // If "rest" is empty, we just did this search above.
-            const packageDirectory = combinePaths(nodeModulesDirectory, packageName);
+            if (packageDirectory === undefined) packageDirectory = combinePaths(nodeModulesDirectory!, packageName!);
 
             // Don't use a "types" or "main" from here because we're not loading the root, but a subdirectory -- just here for the packageId and path mappings.
             packageInfo = getPackageJsonInfo(packageDirectory, !nodeModulesDirectoryExists, state);
@@ -2424,4 +2482,64 @@ namespace ts {
     function toSearchResult<T>(value: T | undefined): SearchResult<T> {
         return value !== undefined ? { value } : undefined;
     }
+
+    /**
+     * We only allow PnP to be used as a resolution strategy if TypeScript
+     * itself is executed under a PnP runtime (and we only allow it to access
+     * the current PnP runtime, not any on the disk). This ensures that we
+     * don't execute potentially malicious code that didn't already have a
+     * chance to be executed (if we're running within the runtime, it means
+     * that the runtime has already been executed).
+     * @internal
+     */
+    function getPnpApi(path: string) {
+        const {findPnpApi} = require("module");
+        if (findPnpApi === undefined) {
+            return undefined;
+        }
+        return findPnpApi(`${path}/`);
+    }
+
+    function loadPnpPackageResolution(packageName: string, containingDirectory: string) {
+        try {
+            const resolution = getPnpApi(containingDirectory).resolveToUnqualified(packageName, `${containingDirectory}/`, { considerBuiltins: false });
+            return normalizeSlashes(resolution).replace(/\/$/, "");
+        }
+        catch {
+            // Nothing to do
+        }
+    }
+
+    function loadPnpTypePackageResolution(packageName: string, containingDirectory: string) {
+        return loadPnpPackageResolution(getTypesPackageName(packageName), containingDirectory);
+    }
+
+    /* @internal */
+    function tryLoadModuleUsingPnpResolution(extensions: Extensions, moduleName: string, containingDirectory: string, state: ModuleResolutionState, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined) {
+        const {packageName, rest} = parsePackageName(moduleName);
+
+        const packageResolution = loadPnpPackageResolution(packageName, containingDirectory);
+        const packageFullResolution = packageResolution
+            ? loadModuleFromPnpResolution(extensions, packageResolution, rest, state, cache, redirectedReference)
+            : undefined;
+
+        let resolved;
+        if (packageFullResolution) {
+            resolved = packageFullResolution;
+        }
+        else if (extensions === Extensions.TypeScript || extensions === Extensions.DtsOnly) {
+            const typePackageResolution = loadPnpTypePackageResolution(packageName, containingDirectory);
+            const typePackageFullResolution = typePackageResolution
+                ? loadModuleFromPnpResolution(Extensions.DtsOnly, typePackageResolution, rest, state, cache, redirectedReference)
+                : undefined;
+
+            if (typePackageFullResolution) {
+                resolved = typePackageFullResolution;
+            }
+        }
+
+        if (resolved) {
+            return toSearchResult(resolved);
+        }
+    }
 }

src/compiler/moduleSpecifiers.ts

@@ -670,7 +670,34 @@ namespace ts.moduleSpecifiers {
         if (!host.fileExists || !host.readFile) {
             return undefined;
         }
-        const parts: NodeModulePathParts = getNodeModulePathParts(path)!;
+        let parts: NodeModulePathParts | PackagePathParts | undefined
+            = getNodeModulePathParts(path);
+
+        let packageName: string | undefined;
+        if (!parts && typeof process.versions.pnp !== "undefined") {
+            const {findPnpApi} = require("module");
+            const pnpApi = findPnpApi(path);
+            const locator = pnpApi?.findPackageLocator(path);
+            // eslint-disable-next-line no-null/no-null
+            if (locator !== null && locator !== undefined) {
+                const sourceLocator = pnpApi.findPackageLocator(`${sourceDirectory}/`);
+                // Don't use the package name when the imported file is inside
+                // the source directory (prefer a relative path instead)
+                if (locator === sourceLocator) {
+                    return undefined;
+                }
+                const information = pnpApi.getPackageInformation(locator);
+                packageName = locator.name;
+                parts = {
+                    topLevelNodeModulesIndex: undefined,
+                    topLevelPackageNameIndex: undefined,
+                    // The last character from packageLocation is the trailing "/", we want to point to it
+                    packageRootIndex: information.packageLocation.length - 1,
+                    fileNameIndex: path.lastIndexOf(`/`),
+                };
+            }
+        }
+
         if (!parts) {
             return undefined;
         }
@@ -713,19 +740,26 @@ namespace ts.moduleSpecifiers {
             return undefined;
         }
 
-        const globalTypingsCacheLocation = host.getGlobalTypingsCacheLocation && host.getGlobalTypingsCacheLocation();
-        // Get a path that's relative to node_modules or the importing file's path
-        // if node_modules folder is in this folder or any of its parent folders, no need to keep it.
-        const pathToTopLevelNodeModules = getCanonicalFileName(moduleSpecifier.substring(0, parts.topLevelNodeModulesIndex));
-        if (!(startsWith(sourceDirectory, pathToTopLevelNodeModules) || globalTypingsCacheLocation && startsWith(getCanonicalFileName(globalTypingsCacheLocation), pathToTopLevelNodeModules))) {
-            return undefined;
+        // If PnP is enabled the node_modules entries we'll get will always be relevant even if they
+        // are located in a weird path apparently outside of the source directory
+        if (typeof process.versions.pnp === "undefined") {
+            const globalTypingsCacheLocation = host.getGlobalTypingsCacheLocation && host.getGlobalTypingsCacheLocation();
+            // Get a path that's relative to node_modules or the importing file's path
+            // if node_modules folder is in this folder or any of its parent folders, no need to keep it.
+            const pathToTopLevelNodeModules = getCanonicalFileName(moduleSpecifier.substring(0, parts.topLevelNodeModulesIndex));
+            if (!(startsWith(sourceDirectory, pathToTopLevelNodeModules) || globalTypingsCacheLocation && startsWith(getCanonicalFileName(globalTypingsCacheLocation), pathToTopLevelNodeModules))) {
+                return undefined;
+            }
         }
 
         // If the module was found in @types, get the actual Node package name
-        const nodeModulesDirectoryName = moduleSpecifier.substring(parts.topLevelPackageNameIndex + 1);
-        const packageName = getPackageNameFromTypesPackageName(nodeModulesDirectoryName);
+        const nodeModulesDirectoryName = typeof packageName !== "undefined"
+            ? packageName + moduleSpecifier.substring(parts.packageRootIndex)
+            : moduleSpecifier.substring(parts.topLevelPackageNameIndex! + 1);
+
+        const packageNameFromPath = getPackageNameFromTypesPackageName(nodeModulesDirectoryName);
         // For classic resolution, only allow importing from node_modules/@types, not other node_modules
-        return getEmitModuleResolutionKind(options) === ModuleResolutionKind.Classic && packageName === nodeModulesDirectoryName ? undefined : packageName;
+        return getEmitModuleResolutionKind(options) === ModuleResolutionKind.Classic && packageNameFromPath === nodeModulesDirectoryName ? undefined : packageNameFromPath;
 
         function tryDirectoryWithPackageJson(packageRootIndex: number): { moduleFileToTry: string, packageRootPath?: string, blockedByExports?: true, verbatimFromExports?: true } {
             const packageRootPath = path.substring(0, packageRootIndex);
@@ -785,8 +819,8 @@ namespace ts.moduleSpecifiers {
 
             // If the file is /index, it can be imported by its directory name
             // IFF there is not _also_ a file by the same name
-            if (getCanonicalFileName(fullModulePathWithoutExtension.substring(parts.fileNameIndex)) === "/index" && !tryGetAnyFileFromPath(host, fullModulePathWithoutExtension.substring(0, parts.fileNameIndex))) {
-                return fullModulePathWithoutExtension.substring(0, parts.fileNameIndex);
+            if (getCanonicalFileName(fullModulePathWithoutExtension.substring(parts!.fileNameIndex)) === "/index" && !tryGetAnyFileFromPath(host, fullModulePathWithoutExtension.substring(0, parts!.fileNameIndex))) {
+                return fullModulePathWithoutExtension.substring(0, parts!.fileNameIndex);
             }
 
             return fullModulePathWithoutExtension;

src/compiler/sys.ts

@@ -1517,6 +1517,11 @@ namespace ts {
             }
 
             function isFileSystemCaseSensitive(): boolean {
+                // The PnP runtime is always case-sensitive
+                // @ts-ignore
+                if (process.versions.pnp) {
+                    return true;
+                }
                 // win32\win64 are case insensitive platforms
                 if (platform === "win32" || platform === "win64") {
                     return false;

src/compiler/utilities.ts

@@ -7602,6 +7602,14 @@ namespace ts {
         readonly packageRootIndex: number;
         readonly fileNameIndex: number;
     }
+
+    export interface PackagePathParts {
+        readonly topLevelNodeModulesIndex: undefined;
+        readonly topLevelPackageNameIndex: undefined;
+        readonly packageRootIndex: number;
+        readonly fileNameIndex: number;
+    }
+
     export function getNodeModulePathParts(fullPath: string): NodeModulePathParts | undefined {
         // If fullPath can't be valid module file within node_modules, returns undefined.
         // Example of expected pattern: /base/path/node_modules/[@scope/otherpackage/@otherscope/node_modules/]package/[subdirectory/]file.js