microsoft · arcanis · Apr 2, 2021
diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
@@ -110,6 +110,10 @@ import {
     versionMajorMinor,
     VersionRange,
 } from "./_namespaces/ts";
+import {
+    getPnpApi,
+    getPnpTypeRoots,
+} from "./pnp";
 
 /** @internal */
 export function trace(host: ModuleResolutionHost, message: DiagnosticMessage, ...args: any[]): void {
@@ -471,7 +475,7 @@ export function getEffectiveTypeRoots(options: CompilerOptions, host: GetEffecti
  * Returns the path to every node_modules/@types directory from some ancestor directory.
  * Returns undefined if there are none.
  */
-function getDefaultTypeRoots(currentDirectory: string): string[] | undefined {
+function getNodeModulesTypeRoots(currentDirectory: string) {
     let typeRoots: string[] | undefined;
     forEachAncestorDirectory(normalizePath(currentDirectory), directory => {
         const atTypes = combinePaths(directory, nodeModulesAtTypes);
@@ -486,6 +490,18 @@ function arePathsEqual(path1: string, path2: string, host: ModuleResolutionHost)
     return comparePaths(path1, path2, !useCaseSensitiveFileNames) === Comparison.EqualTo;
 }
 
+function getDefaultTypeRoots(currentDirectory: string): string[] | undefined {
+    const nmTypes = getNodeModulesTypeRoots(currentDirectory);
+    const pnpTypes = getPnpTypeRoots(currentDirectory);
+
+    if (nmTypes?.length) {
+        return [...nmTypes, ...pnpTypes];
+    }
+    else if (pnpTypes.length) {
+        return pnpTypes;
+    }
+}
+
 function getOriginalAndResolvedFileName(fileName: string, host: ModuleResolutionHost, traceEnabled: boolean) {
     const resolvedFileName = realPath(fileName, host, traceEnabled);
     const pathsAreEqual = arePathsEqual(fileName, resolvedFileName, host);
@@ -770,6 +786,18 @@ export function resolvePackageNameToPackageJson(
 ): PackageJsonInfo | undefined {
     const moduleResolutionState = getTemporaryModuleResolutionState(cache?.getPackageJsonInfoCache(), host, options);
 
+    const pnpapi = getPnpApi(containingDirectory);
+    if (pnpapi) {
+        try {
+            const resolution = pnpapi.resolveToUnqualified(packageName, `${containingDirectory}/`, { considerBuiltins: false });
+            const candidate = normalizeSlashes(resolution).replace(/\/$/, "");
+            return getPackageJsonInfo(candidate, /*onlyRecordFailures*/ false, moduleResolutionState);
+        }
+        catch {
+            return;
+        }
+    }
+
     return forEachAncestorDirectory(containingDirectory, ancestorDirectory => {
         if (getBaseFileName(ancestorDirectory) !== "node_modules") {
             const nodeModulesFolder = combinePaths(ancestorDirectory, "node_modules");
@@ -2938,7 +2966,16 @@ function loadModuleFromNearestNodeModulesDirectoryWorker(extensions: Extensions,
     }
 
     function lookup(extensions: Extensions) {
-        return forEachAncestorDirectory(normalizeSlashes(directory), ancestorDirectory => {
+        const issuer = normalizeSlashes(directory);
+        if (getPnpApi(issuer)) {
+            const resolutionFromCache = tryFindNonRelativeModuleNameInCache(cache, moduleName, mode, issuer, redirectedReference, state);
+            if (resolutionFromCache) {
+                return resolutionFromCache;
+            }
+            return toSearchResult(loadModuleFromImmediateNodeModulesDirectoryPnP(extensions, moduleName, issuer, state, typesScopeOnly, cache, redirectedReference));
+        }
+
+        return forEachAncestorDirectory(issuer, ancestorDirectory => {
             if (getBaseFileName(ancestorDirectory) !== "node_modules") {
                 const resolutionFromCache = tryFindNonRelativeModuleNameInCache(cache, moduleName, mode, ancestorDirectory, redirectedReference, state);
                 if (resolutionFromCache) {
@@ -2977,11 +3014,34 @@ function loadModuleFromImmediateNodeModulesDirectory(extensions: Extensions, mod
     }
 }
 
+function loadModuleFromImmediateNodeModulesDirectoryPnP(extensions: Extensions, moduleName: string, directory: string, state: ModuleResolutionState, typesScopeOnly: boolean, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined): Resolved | undefined {
+    const issuer = normalizeSlashes(directory);
+
+    if (!typesScopeOnly) {
+        const packageResult = tryLoadModuleUsingPnpResolution(extensions, moduleName, issuer, state, cache, redirectedReference);
+        if (packageResult) {
+            return packageResult;
+        }
+    }
+
+    if (extensions & Extensions.Declaration) {
+        return tryLoadModuleUsingPnpResolution(Extensions.Declaration, `@types/${mangleScopedPackageNameWithTrace(moduleName, state)}`, issuer, state, cache, redirectedReference);
+    }
+}
+
 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));
     const { packageName, rest } = parsePackageName(moduleName);
     const packageDirectory = combinePaths(nodeModulesDirectory, packageName);
+    return loadModuleFromSpecificNodeModulesDirectoryImpl(extensions, nodeModulesDirectoryExists, state, cache, redirectedReference, candidate, rest, packageDirectory);
+}
 
+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, /*nodeModulesDirectoryExists*/ true, state, cache, redirectedReference, candidate, rest, packageDirectory);
+}
+
+function loadModuleFromSpecificNodeModulesDirectoryImpl(extensions: Extensions, nodeModulesDirectoryExists: boolean, state: ModuleResolutionState, cache: ModuleResolutionCache | undefined, redirectedReference: ResolvedProjectReference | undefined, candidate: string, rest: string, packageDirectory: string): Resolved | undefined {
     let rootPackageInfo: PackageJsonInfo | undefined;
     // First look for a nested package.json, as in `node_modules/foo/bar/package.json`.
     let packageInfo = getPackageJsonInfo(candidate, !nodeModulesDirectoryExists, state);
@@ -3306,3 +3366,22 @@ function useCaseSensitiveFileNames(state: ModuleResolutionState) {
         typeof state.host.useCaseSensitiveFileNames === "boolean" ? state.host.useCaseSensitiveFileNames :
         state.host.useCaseSensitiveFileNames();
 }
+
+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 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);
+    return packageResolution
+        ? loadModuleFromPnpResolution(extensions, packageResolution, rest, state, cache, redirectedReference)
+        : undefined;
+}
diff --git a/src/compiler/moduleSpecifiers.ts b/src/compiler/moduleSpecifiers.ts
@@ -84,6 +84,7 @@ import {
     NodeFlags,
     NodeModulePathParts,
     normalizePath,
+    PackagePathParts,
     Path,
     pathContainsNodeModules,
     pathIsBareSpecifier,
@@ -110,6 +111,9 @@ import {
     TypeChecker,
     UserPreferences,
 } from "./_namespaces/ts";
+import {
+    getPnpApi,
+} from "./pnp";
 
 // Used by importFixes, getEditsForFileRename, and declaration emit to synthesize import module specifiers.
 
@@ -641,7 +645,17 @@ function getAllModulePathsWorker(importingFileName: Path, importedFileName: stri
         host,
         /*preferSymlinks*/ true,
         (path, isRedirect) => {
-            const isInNodeModules = pathContainsNodeModules(path);
+            let isInNodeModules = pathContainsNodeModules(path);
+
+            const pnpapi = getPnpApi(path);
+            if (!isInNodeModules && pnpapi) {
+                const fromLocator = pnpapi.findPackageLocator(importingFileName);
+                const toLocator = pnpapi.findPackageLocator(path);
+                if (fromLocator && toLocator && fromLocator !== toLocator) {
+                    isInNodeModules = true;
+                }
+            }
+
             allFileNames.set(path, { path: getCanonicalFileName(path), isRedirect, isInNodeModules });
             importedFileFromNodeModules = importedFileFromNodeModules || isInNodeModules;
             // don't return value, so we collect everything
@@ -907,7 +921,51 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
     if (!host.fileExists || !host.readFile) {
         return undefined;
     }
-    const parts: NodeModulePathParts = getNodeModulePathParts(path)!;
+    let parts: NodeModulePathParts | PackagePathParts | undefined = getNodeModulePathParts(path);
+
+    let pnpPackageName: string | undefined;
+
+    const pnpApi = getPnpApi(path);
+    if (pnpApi) {
+        const fromLocator = pnpApi.findPackageLocator(importingSourceFile.fileName);
+        const toLocator = pnpApi.findPackageLocator(path);
+
+        // Don't use the package name when the imported file is inside
+        // the source directory (prefer a relative path instead)
+        if (fromLocator === toLocator) {
+            return undefined;
+        }
+
+        if (fromLocator && toLocator) {
+            const fromInfo = pnpApi.getPackageInformation(fromLocator);
+            if (toLocator.reference === fromInfo.packageDependencies.get(toLocator.name)) {
+                pnpPackageName = toLocator.name;
+            }
+            else {
+                // Aliased dependencies
+                for (const [name, reference] of fromInfo.packageDependencies) {
+                    if (Array.isArray(reference)) {
+                        if (reference[0] === toLocator.name && reference[1] === toLocator.reference) {
+                            pnpPackageName = name;
+                            break;
+                        }
+                    }
+                }
+            }
+
+            if (!parts) {
+                const toInfo = pnpApi.getPackageInformation(toLocator);
+                parts = {
+                    topLevelNodeModulesIndex: undefined,
+                    topLevelPackageNameIndex: undefined,
+                    // The last character from packageLocation is the trailing "/", we want to point to it
+                    packageRootIndex: toInfo.packageLocation.length - 1,
+                    fileNameIndex: path.lastIndexOf(`/`),
+                };
+            }
+        }
+    }
+
     if (!parts) {
         return undefined;
     }
@@ -952,19 +1010,26 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
         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 pnpPackageName !== "undefined"
+        ? pnpPackageName + 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);
@@ -979,8 +1044,8 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
                 // The package name that we found in node_modules could be different from the package
                 // name in the package.json content via url/filepath dependency specifiers. We need to
                 // use the actual directory name, so don't look at `packageJsonContent.name` here.
-                const nodeModulesDirectoryName = packageRootPath.substring(parts.topLevelPackageNameIndex + 1);
-                const packageName = getPackageNameFromTypesPackageName(nodeModulesDirectoryName);
+                const nodeModulesDirectoryName = packageRootPath.substring(parts!.topLevelPackageNameIndex! + 1);
+                const packageName = getPackageNameFromTypesPackageName(pnpPackageName ? pnpPackageName : nodeModulesDirectoryName);
                 const conditions = getConditions(options, importMode === ModuleKind.ESNext);
                 const fromExports = packageJsonContent.exports
                     ? tryGetModuleNameFromExports(options, path, packageRootPath, packageName, packageJsonContent.exports, conditions)
@@ -1046,7 +1111,7 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
         }
         else {
             // No package.json exists; an index.js will still resolve as the package name
-            const fileName = getCanonicalFileName(moduleFileToTry.substring(parts.packageRootIndex + 1));
+            const fileName = getCanonicalFileName(moduleFileToTry.substring(parts!.packageRootIndex + 1));
             if (fileName === "index.d.ts" || fileName === "index.js" || fileName === "index.ts" || fileName === "index.tsx") {
                 return { moduleFileToTry, packageRootPath };
             }

diff --git a/src/compiler/pnp.ts b/src/compiler/pnp.ts
@@ -0,0 +1,80 @@
+import {
+    getDirectoryPath,
+    resolvePath,
+} from "./path";
+
+export function getPnpApi(path: string) {
+    if (typeof process.versions.pnp === "undefined") {
+        return;
+    }
+
+    const { findPnpApi } = require("module");
+    if (findPnpApi) {
+        return findPnpApi(`${path}/`);
+    }
+}
+
+export function getPnpApiPath(path: string): string | undefined {
+    // eslint-disable-next-line no-null/no-null
+    return getPnpApi(path)?.resolveRequest("pnpapi", /*issuer*/ null);
+}
+
+export function getPnpTypeRoots(currentDirectory: string) {
+    const pnpApi = getPnpApi(currentDirectory);
+    if (!pnpApi) {
+        return [];
+    }
+
+    // Some TS consumers pass relative paths that aren't normalized
+    currentDirectory = resolvePath(currentDirectory);
+
+    const currentPackage = pnpApi.findPackageLocator(`${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(`@types/`) && referencish !== null) {
+            const dependencyLocator = pnpApi.getLocator(name, referencish);
+            const { packageLocation } = pnpApi.getPackageInformation(dependencyLocator);
+
+            typeRoots.push(getDirectoryPath(packageLocation));
+        }
+    }
+
+    return typeRoots;
+}
+
+export function isImportablePathPnp(fromPath: string, toPath: string): boolean {
+    const pnpApi = getPnpApi(fromPath);
+
+    const fromLocator = pnpApi.findPackageLocator(fromPath);
+    const toLocator = pnpApi.findPackageLocator(toPath);
+
+    // eslint-disable-next-line no-null/no-null
+    if (toLocator === null) {
+        return false;
+    }
+
+    const fromInfo = pnpApi.getPackageInformation(fromLocator);
+    const toReference = fromInfo.packageDependencies.get(toLocator.name);
+
+    if (toReference) {
+        return toReference === toLocator.reference;
+    }
+
+    // Aliased dependencies
+    for (const reference of fromInfo.packageDependencies.values()) {
+        if (Array.isArray(reference)) {
+            if (reference[0] === toLocator.name && reference[1] === toLocator.reference) {
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
@@ -1728,6 +1728,10 @@ export let sys: System = (() => {
         }
 
         function isFileSystemCaseSensitive(): boolean {
+            // The PnP runtime is always case-sensitive
+            if (typeof process.versions.pnp !== `undefined`) {
+                return true;
+            }
             // win32\win64 are case insensitive platforms
             if (platform === "win32" || platform === "win64") {
                 return false;

diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
@@ -10230,6 +10230,15 @@ export interface NodeModulePathParts {
     readonly packageRootIndex: number;
     readonly fileNameIndex: number;
 }
+
+/** @internal */
+export interface PackagePathParts {
+    readonly topLevelNodeModulesIndex: undefined;
+    readonly topLevelPackageNameIndex: undefined;
+    readonly packageRootIndex: number;
+    readonly fileNameIndex: number;
+}
+
 /** @internal */
 export function getNodeModulePathParts(fullPath: string): NodeModulePathParts | undefined {
     // If fullPath can't be valid module file within node_modules, returns undefined.