Fix package.json auto imports for pnpm without project references

src/compiler/moduleNameResolver.ts

@@ -43,11 +43,12 @@ namespace ts {
         packageId: PackageId | undefined;
         /**
          * When the resolved is not created from cache, the value is
-         *  - string if original Path if it is symbolic link to the resolved path
-         *  - undefined if path is not a symbolic link
+         *  - string if it is symbolic link to the resolved `path`
+         *  - undefined if `path` is not a symbolic link
          * When the resolved is created using value from cache of ResolvedModuleWithFailedLookupLocations, the value is:
-         *  - string if original Path if it is symbolic link to the resolved path
-         *  - true if path is not a symbolic link - this indicates that the originalPath calculation is already done and needs to be skipped
+         *  - string if it is symbolic link to the resolved `path`
+         *  - true if `path` is not a symbolic link - this indicates that the `originalPath` calculation is already done and needs to be skipped
+         * Note: This is a file name with preserved original casing, not a normalized `Path`.
          */
         originalPath?: string | true;
     }
@@ -339,7 +340,13 @@ namespace ts {
         if (resolved) {
             const { fileName, packageId } = resolved;
             const resolvedFileName = options.preserveSymlinks ? fileName : realPath(fileName, host, traceEnabled);
-            resolvedTypeReferenceDirective = { primary, resolvedFileName, packageId, isExternalLibraryImport: pathContainsNodeModules(fileName) };
+            resolvedTypeReferenceDirective = {
+                primary,
+                resolvedFileName,
+                originalPath: fileName === resolvedFileName ? undefined : fileName,
+                packageId,
+                isExternalLibraryImport: pathContainsNodeModules(fileName),
+            };
         }
         result = { resolvedTypeReferenceDirective, failedLookupLocations };
         perFolderCache?.set(typeReferenceDirectiveName, result);

src/compiler/types.ts

@@ -6407,7 +6407,10 @@ namespace ts {
      * If changing this, remember to change `moduleResolutionIsEqualTo`.
      */
     export interface ResolvedModuleFull extends ResolvedModule {
-        /* @internal */
+        /**
+         * @internal
+         * This is a file name with preserved original casing, not a normalized `Path`.
+         */
         readonly originalPath?: string;
         /**
          * Extension of resolvedFileName. This must match what's at the end of resolvedFileName.
@@ -6458,6 +6461,12 @@ namespace ts {
         primary: boolean;
         // The location of the .d.ts file we located, or undefined if resolution failed
         resolvedFileName: string | undefined;
+        /**
+         * @internal
+         * The location of the symlink to the .d.ts file we found, if `resolvedFileName` was the realpath.
+         * This is a file name with preserved original casing, not a normalized `Path`.
+         */
+        originalPath?: string;
         packageId?: PackageId;
         /** True if `resolvedFileName` comes from `node_modules`. */
         isExternalLibraryImport?: boolean;

src/compiler/utilities.ts

@@ -205,7 +205,9 @@ namespace ts {
     }
 
     export function typeDirectiveIsEqualTo(oldResolution: ResolvedTypeReferenceDirective, newResolution: ResolvedTypeReferenceDirective): boolean {
-        return oldResolution.resolvedFileName === newResolution.resolvedFileName && oldResolution.primary === newResolution.primary;
+        return oldResolution.resolvedFileName === newResolution.resolvedFileName
+            && oldResolution.primary === newResolution.primary
+            && oldResolution.originalPath === newResolution.originalPath;
     }
 
     export function hasChangesInResolutions<T>(
@@ -6145,6 +6147,8 @@ namespace ts {
         getSymlinkedFiles(): ReadonlyESMap<Path, string> | undefined;
         setSymlinkedDirectory(symlink: string, real: SymlinkedDirectory | false): void;
         setSymlinkedFile(symlinkPath: Path, real: string): void;
+        /*@internal*/
+        setSymlinkedDirectoryFromSymlinkedFile(symlink: string, real: string): void;
     }
 
     export function createSymlinkCache(cwd: string, getCanonicalFileName: GetCanonicalFileName): SymlinkCache {
@@ -6168,16 +6172,31 @@ namespace ts {
                     }
                     (symlinkedDirectories || (symlinkedDirectories = new Map())).set(symlinkPath, real);
                 }
-            }
+            },
+            setSymlinkedDirectoryFromSymlinkedFile(symlink, real) {
+                this.setSymlinkedFile(toPath(symlink, cwd, getCanonicalFileName), real);
+                const [commonResolved, commonOriginal] = guessDirectorySymlink(real, symlink, cwd, getCanonicalFileName) || emptyArray;
+                if (commonResolved && commonOriginal) {
+                    this.setSymlinkedDirectory(commonOriginal, {
+                        real: commonResolved,
+                        realPath: toPath(commonResolved, cwd, getCanonicalFileName),
+                    });
+                }
+            },
         };
     }
 
     export function discoverProbableSymlinks(files: readonly SourceFile[], getCanonicalFileName: GetCanonicalFileName, cwd: string): SymlinkCache {
         const cache = createSymlinkCache(cwd, getCanonicalFileName);
-        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)))));
+        const symlinks = flatMap(files, sf => {
+            const pairs = sf.resolvedModules && arrayFrom(mapDefinedIterator(sf.resolvedModules.values(), res =>
+                res?.originalPath ? [res.resolvedFileName, res.originalPath] as const : undefined));
+            return concatenate(pairs, sf.resolvedTypeReferenceDirectiveNames && arrayFrom(mapDefinedIterator(sf.resolvedTypeReferenceDirectiveNames.values(), res =>
+                res?.originalPath && res.resolvedFileName ? [res.resolvedFileName, res.originalPath] as const : undefined)));
+        });
+
         for (const [resolvedPath, originalPath] of symlinks) {
+            cache.setSymlinkedFile(toPath(originalPath, cwd, getCanonicalFileName), resolvedPath);
             const [commonResolved, commonOriginal] = guessDirectorySymlink(resolvedPath, originalPath, cwd, getCanonicalFileName) || emptyArray;
             if (commonResolved && commonOriginal) {
                 cache.setSymlinkedDirectory(

src/server/project.ts

@@ -1901,16 +1901,20 @@ namespace ts.server {
                     compilerOptions,
                     moduleResolutionHost));
 
+                const program = hostProject.getCurrentProgram()!;
+                const symlinkCache = hostProject.getSymlinkCache();
                 for (const resolution of resolutions) {
                     if (!resolution.resolvedTypeReferenceDirective?.resolvedFileName) continue;
-                    const { resolvedFileName } = resolution.resolvedTypeReferenceDirective;
-                    const fileName = moduleResolutionHost.realpath?.(resolvedFileName) || resolvedFileName;
-                    if (!hostProject.getCurrentProgram()!.getSourceFile(fileName) && !hostProject.getCurrentProgram()!.getSourceFile(resolvedFileName)) {
-                        rootNames = append(rootNames, fileName);
+                    const { resolvedFileName, originalPath } = resolution.resolvedTypeReferenceDirective;
+                    if (!program.getSourceFile(resolvedFileName) && (!originalPath || !program.getSourceFile(originalPath))) {
+                        rootNames = append(rootNames, resolvedFileName);
                         // Avoid creating a large project that would significantly slow down time to editor interactivity
                         if (dependencySelection === PackageJsonAutoImportPreference.Auto && rootNames.length > this.maxDependencies) {
                             return ts.emptyArray;
                         }
+                        if (originalPath) {
+                            symlinkCache.setSymlinkedDirectoryFromSymlinkedFile(originalPath, resolvedFileName);
+                        }
                     }
                 }
             }

tests/cases/fourslash/server/autoImportProvider_pnpm.ts

@@ -0,0 +1,21 @@
+/// <reference path="../fourslash.ts" />
+
+// @Filename: /tsconfig.json
+//// { "compilerOptions": { "module": "commonjs" } }
+
+// @Filename: /package.json
+//// { "dependencies": { "mobx": "*" } }
+
+// @Filename: /node_modules/.pnpm/[email protected]/node_modules/mobx/package.json
+//// { "types": "dist/mobx.d.ts" }
+
+// @Filename: /node_modules/.pnpm/[email protected]/node_modules/mobx/dist/mobx.d.ts
+//// export declare function autorun(): void;
+
+// @Filename: /index.ts
+//// autorun/**/
+
+// @link: /node_modules/.pnpm/[email protected]/node_modules/mobx -> /node_modules/mobx
+
+goTo.marker("");
+verify.importFixAtPosition([`import { autorun } from "mobx";\r\n\r\nautorun`]);