Replaces the default module index resolver with '/index' instead of '' when handling internal routing for dts bundles (#39277)

* Adds support for declaring the bundled name of a dts module export

Co-authored-by: Wesley Wigham <[email protected]>

* Adds baselines

* Update the tests

* Try to reduce the scope of the bundledPackageName error

* Use the flag in more baselines

* Get it green

* More tests

* Handle more feedback

* More test cleanup

* Set the moduleResolution for the tsconfigs

Co-authored-by: Wesley Wigham <[email protected]>

Author: Orta Therox

src/compiler/checker.ts

@@ -4299,6 +4299,7 @@ namespace ts {
                         getProjectReferenceRedirect: fileName => host.getProjectReferenceRedirect(fileName),
                         isSourceOfProjectReferenceRedirect: fileName => host.isSourceOfProjectReferenceRedirect(fileName),
                         fileExists: fileName => host.fileExists(fileName),
+                        getCompilerOptions: () => host.getCompilerOptions()
                     } : undefined },
                     encounteredError: false,
                     visitedTypes: undefined,
@@ -5933,7 +5934,8 @@ namespace ts {
                                     const resolverHost = {
                                         getCanonicalFileName,
                                         getCurrentDirectory: () => context.tracker.moduleResolverHost!.getCurrentDirectory(),
-                                        getCommonSourceDirectory: () => context.tracker.moduleResolverHost!.getCommonSourceDirectory()
+                                        getCommonSourceDirectory: () => context.tracker.moduleResolverHost!.getCommonSourceDirectory(),
+                                        getCompilerOptions: () => context.tracker.moduleResolverHost!.getCompilerOptions()
                                     };
                                     const newName = getResolvedExternalModuleName(resolverHost, targetFile);
                                     return factory.createStringLiteral(newName);

src/compiler/commandLineParser.ts

@@ -1002,6 +1002,14 @@ namespace ts {
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Emit_class_fields_with_Define_instead_of_Set,
         },
+        {
+            name: "bundledPackageName",
+            type: "string",
+            affectsEmit: true,
+            category: Diagnostics.Advanced_Options,
+            description: Diagnostics.Provides_a_root_package_name_when_using_outFile_with_declarations,
+        },
+
         {
             name: "keyofStringsOnly",
             type: "boolean",

src/compiler/diagnosticMessages.json

@@ -1184,7 +1184,14 @@
         "category": "Error",
         "code": 1389
     },
-
+    "Provides a root package name when using outFile with declarations.": {
+        "category": "Message",
+        "code": 1390
+    },
+    "The `bundledPackageName` option must be provided when using outFile and node module resolution with declaration emit.": {
+        "category": "Error",
+        "code": 1391
+    },
     "The types of '{0}' are incompatible between these types.": {
         "category": "Error",
         "code": 2200

src/compiler/moduleSpecifiers.ts

@@ -157,7 +157,7 @@ namespace ts.moduleSpecifiers {
     }
 
     function getLocalModuleSpecifier(moduleFileName: string, { getCanonicalFileName, sourceDirectory }: Info, compilerOptions: CompilerOptions, { ending, relativePreference }: Preferences): string {
-        const { baseUrl, paths, rootDirs } = compilerOptions;
+        const { baseUrl, paths, rootDirs, bundledPackageName } = compilerOptions;
 
         const relativePath = rootDirs && tryGetModuleNameFromRootDirs(rootDirs, moduleFileName, sourceDirectory, getCanonicalFileName, ending, compilerOptions) ||
             removeExtensionAndIndexPostFix(ensurePathIsNonModuleName(getRelativePathFromDirectory(sourceDirectory, moduleFileName, getCanonicalFileName)), ending, compilerOptions);
@@ -170,8 +170,9 @@ namespace ts.moduleSpecifiers {
             return relativePath;
         }
 
-        const importRelativeToBaseUrl = removeExtensionAndIndexPostFix(relativeToBaseUrl, ending, compilerOptions);
-        const fromPaths = paths && tryGetModuleNameFromPaths(removeFileExtension(relativeToBaseUrl), importRelativeToBaseUrl, paths);
+        const bundledPkgReference = bundledPackageName ? combinePaths(bundledPackageName, relativeToBaseUrl) : relativeToBaseUrl;
+        const importRelativeToBaseUrl = removeExtensionAndIndexPostFix(bundledPkgReference, ending, compilerOptions);
+        const fromPaths = paths && tryGetModuleNameFromPaths(removeFileExtension(bundledPkgReference), importRelativeToBaseUrl, paths);
         const nonRelative = fromPaths === undefined ? importRelativeToBaseUrl : fromPaths;
 
         if (relativePreference === RelativePreference.NonRelative) {
@@ -278,7 +279,7 @@ namespace ts.moduleSpecifiers {
                 const isInNodeModules = pathContainsNodeModules(path);
                 allFileNames.set(path, { path: getCanonicalFileName(path), isRedirect, isInNodeModules });
                 importedFileFromNodeModules = importedFileFromNodeModules || isInNodeModules;
-                // dont return value, so we collect everything
+                // don't return value, so we collect everything
             }
         );
 

src/compiler/program.ts

@@ -3139,6 +3139,11 @@ namespace ts {
                 }
             }
 
+            // Without a package name, for multiple files being bundled into a .d.ts file you basically get a file which doesn't wrk
+            if (outputFile && getEmitDeclarations(options) && getEmitModuleResolutionKind(options) === ModuleResolutionKind.NodeJs && !options.bundledPackageName) {
+                createDiagnosticForOptionName(Diagnostics.The_bundledPackageName_option_must_be_provided_when_using_outFile_and_node_module_resolution_with_declaration_emit, options.out ? "out" : "outFile");
+            }
+
             if (options.resolveJsonModule) {
                 if (getEmitModuleResolutionKind(options) !== ModuleResolutionKind.NodeJs) {
                     createDiagnosticForOptionName(Diagnostics.Option_resolveJsonModule_cannot_be_specified_without_node_module_resolution_strategy, "resolveJsonModule");

src/compiler/types.ts

@@ -5723,6 +5723,7 @@ namespace ts {
         /** An error if set - this should only go through the -b pipeline and not actually be observed */
         /*@internal*/
         build?: boolean;
+        bundledPackageName?: string;
         charset?: string;
         checkJs?: boolean;
         /* @internal */ configFilePath?: string;
@@ -7843,6 +7844,7 @@ namespace ts {
         readonly redirectTargetsMap: RedirectTargetsMap;
         getProjectReferenceRedirect(fileName: string): string | undefined;
         isSourceOfProjectReferenceRedirect(fileName: string): boolean;
+        getCompilerOptions(): CompilerOptions;
     }
 
     // Note: this used to be deprecated in our public API, but is still used internally

src/compiler/utilities.ts

@@ -4021,6 +4021,7 @@ namespace ts {
         getCanonicalFileName(p: string): string;
         getCommonSourceDirectory(): string;
         getCurrentDirectory(): string;
+        getCompilerOptions(): CompilerOptions;
     }
 
     export function getResolvedExternalModuleName(host: ResolveModuleNameResolutionHost, file: SourceFile, referenceFile?: SourceFile): string {
@@ -4044,7 +4045,16 @@ namespace ts {
         const filePath = getNormalizedAbsolutePath(fileName, host.getCurrentDirectory());
         const relativePath = getRelativePathToDirectoryOrUrl(dir, filePath, dir, getCanonicalFileName, /*isAbsolutePathAnUrl*/ false);
         const extensionless = removeFileExtension(relativePath);
-        return referencePath ? ensurePathIsNonModuleName(extensionless) : extensionless;
+        if (referencePath) {
+            return ensurePathIsNonModuleName(extensionless);
+        }
+        const options = host.getCompilerOptions();
+        const rootPkgName = options.bundledPackageName || "";
+        const newPath = combinePaths(rootPkgName, extensionless);
+        if (rootPkgName && getEmitModuleResolutionKind(options) === ModuleResolutionKind.NodeJs && endsWith(newPath, "/index")) {
+            return newPath.slice(0, newPath.length - "/index".length);
+        }
+        return newPath;
     }
 
     export function getOwnEmitOutputFilePath(fileName: string, host: EmitHost, extension: string) {

src/harness/tsconfig.json

@@ -2,6 +2,7 @@
     "extends": "../tsconfig-base",
     "compilerOptions": {
         "outFile": "../../built/local/harness.js",
+        "moduleResolution": "node",
         "types": [
             "node", "mocha", "chai"
         ],

src/services/utilities.ts

@@ -1773,6 +1773,7 @@ namespace ts {
             redirectTargetsMap: program.redirectTargetsMap,
             getProjectReferenceRedirect: fileName => program.getProjectReferenceRedirect(fileName),
             isSourceOfProjectReferenceRedirect: fileName => program.isSourceOfProjectReferenceRedirect(fileName),
+            getCompilerOptions: () => program.getCompilerOptions()
         };
     }
 

src/testRunner/tsconfig.json

@@ -2,6 +2,7 @@
     "extends": "../tsconfig-noncomposite-base",
     "compilerOptions": {
         "outFile": "../../built/local/run.js",
+        "moduleResolution": "node",
         "composite": false,
         "declaration": false,
         "declarationMap": false,