Resolve relative content mapper packages, always resolve from the config that declares the mapper (#65105)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: andrewbranch <3277153+andrewbranch@users.noreply.github.com>

Author: Copilot

tsc/internal/module/resolver.go

@@ -538,6 +538,14 @@ func (r *DefaultResolver) ResolvePackageDirectory(moduleName string, containingF
 	compilerOptions := GetCompilerOptionsWithRedirect(r.compilerOptions, redirectedReference)
 	containingDirectory := containingFile.Directory()
 	state := newResolutionState(moduleName, containingDirectory, false /*isTypeReferenceDirective*/, resolutionMode, compilerOptions, redirectedReference, r, nil)
+	if tspath.IsExternalModuleNameRelative(moduleName) {
+		packageDirectory := containingDirectory.ResolveDirectory(moduleName)
+		if r.fs.DirectoryExists(packageDirectory) {
+			originalPath, resolvedPath := state.getOriginalAndResolvedFileName(tspath.RootedFilePathFromPath(packageDirectory.AsPath()))
+			return state.createResolvedModuleHandlingSymlink(&resolved{path: resolvedPath, originalPath: originalPath})
+		}
+		return nil
+	}
 	state.resolvePackageDirectoryOnly = true
 	if result := state.loadModuleFromNearestNodeModulesDirectory(false /*typesScopeOnly*/); result != nil && result.path != "" {
 		return state.createResolvedModuleHandlingSymlink(result)

tsc/internal/project/configfileregistrybuilder.go

@@ -799,12 +799,18 @@ func (c *configFileRegistryBuilder) IsContentMapperPackageAllowed(packageDirecto
 	if c.sessionOptions.InitialWorkspaceRoots == nil {
 		return true
 	}
+	caseSensitivity := c.fs.CaseSensitivity()
+	if slices.ContainsFunc(c.sessionOptions.InitialWorkspaceRoots, func(root tspath.RootedDirectoryPath) bool {
+		return caseSensitivity.ContainsPath(root, packageDirectory.AsPath())
+	}) {
+		return true
+	}
 	_, nodeModulesPath, ok := tspath.RootedFilePathFromPath(packageDirectory.AsPath()).SplitAtLastComponent("node_modules")
 	if !ok {
 		return false
 	}
 	return slices.ContainsFunc(c.sessionOptions.InitialWorkspaceRoots, func(root tspath.RootedDirectoryPath) bool {
-		return c.fs.CaseSensitivity().ContainsPath(root, nodeModulesPath.AsPath())
+		return caseSensitivity.ContainsPath(root, nodeModulesPath.AsPath())
 	})
 }
 

tsc/internal/project/contentmapper_test.go

@@ -303,6 +303,7 @@ func TestContentMapperPackageMustBeInWorkspace(t *testing.T) {
 		name             string
 		projectDirectory string
 		workspaceRoots   []string
+		mapperPackage    string
 		mapperPath       string
 		mapperTarget     string
 		allowed          bool
@@ -314,6 +315,30 @@ func TestContentMapperPackageMustBeInWorkspace(t *testing.T) {
 			mapperPath:       "/home/trusted/node_modules/mapper/package.json",
 			allowed:          true,
 		},
+		{
+			name:             "directory mapper in workspace",
+			projectDirectory: "/home/trusted",
+			workspaceRoots:   []string{"/home/trusted"},
+			mapperPackage:    "./mapper",
+			mapperPath:       "/home/trusted/mapper/package.json",
+			allowed:          true,
+		},
+		{
+			name:             "workspace directory mapper symlinked outside",
+			projectDirectory: "/home/trusted",
+			workspaceRoots:   []string{"/home/trusted"},
+			mapperPackage:    "./mapper",
+			mapperPath:       "/home/trusted/mapper",
+			mapperTarget:     "/home/outside/mapper",
+			allowed:          true,
+		},
+		{
+			name:             "directory mapper outside workspace",
+			projectDirectory: "/home/untrusted",
+			workspaceRoots:   []string{"/home/trusted"},
+			mapperPackage:    "./mapper",
+			mapperPath:       "/home/untrusted/mapper/package.json",
+		},
 		{
 			name:             "loose file outside workspace",
 			projectDirectory: "/home/untrusted",
@@ -357,10 +382,14 @@ func TestContentMapperPackageMustBeInWorkspace(t *testing.T) {
 			configPath := test.projectDirectory + "/tsconfig.json"
 			mainPath := test.projectDirectory + "/main.ts"
 			boxPath := test.projectDirectory + "/app.box"
+			mapperPackage := test.mapperPackage
+			if mapperPackage == "" {
+				mapperPackage = "mapper"
+			}
 			files := map[string]any{
 				configPath: `{
 					"compilerOptions": { "target": "es2020", "module": "esnext", "moduleResolution": "bundler" },
-					"contentMappers": [ { "package": "mapper", "extensions": [".box"] } ]
+					"contentMappers": [ { "package": "` + mapperPackage + `", "extensions": [".box"] } ]
 				}`,
 				mainPath: "import { version } from \"./app.box\";\nexport { version };\n",
 				boxPath:  "export const version = #{target};\n",
@@ -491,6 +520,65 @@ func TestContentMapperPackageManifestChangeReloadsConfig(t *testing.T) {
 	assert.Assert(t, strings.Contains(boxFile.Text(), "export const version = 7;"), "expected fixed mapper manifest to be reloaded: %q", boxFile.Text())
 }
 
+func TestRelativeSymlinkedContentMapperPackageManifestChangeReloadsConfig(t *testing.T) {
+	t.Parallel()
+	const packageJsonPath = "/home/mapper/package.json"
+	files := map[string]any{
+		"/home/project/tsconfig.json": `{
+			"compilerOptions": { "target": "es2020", "module": "esnext", "moduleResolution": "bundler" },
+			"contentMappers": [{ "package": "./mapper", "extensions": [".box"] }]
+		}`,
+		"/home/project/mapper": vfstest.Symlink("/home/mapper"),
+		packageJsonPath: `{
+			"name": "mapper",
+			"version": "1.0.0",
+			"typescript": { "contentMapper": { "exec": ["compiler-test-mapper"] } }
+		}`,
+		"/home/project/app.box": "export const version = #{target};\n",
+		"/home/project/main.ts": "import { version } from \"./app.box\";\n",
+	}
+	caps := &lsproto.ResolvedClientCapabilities{}
+	caps.Workspace.DidChangeWatchedFiles.RelativePatternSupport = true
+	ctx := lsproto.WithClientCapabilities(context.Background(), caps)
+	init, utils := projecttestutil.GetSessionInitOptions(files, &project.SessionOptions{
+		CurrentDirectory:   "/home/project",
+		DefaultLibraryPath: bundled.LibPath(),
+		TypingsLocation:    projecttestutil.TestTypingsLocation,
+		PositionEncoding:   lsproto.PositionEncodingKindUTF8,
+		RunExternalCode:    true,
+		WatchEnabled:       true,
+	}, nil)
+	init.BackgroundCtx = ctx
+	init.Spawner = contentmappertest.NewSpawner()
+	session := project.NewSession(init)
+	defer session.Close()
+
+	mainURI := lsproto.DocumentUri("file:///home/project/main.ts")
+	session.DidOpenFile(ctx, mainURI, 1, files["/home/project/main.ts"].(string), lsproto.LanguageKindTypeScript)
+	_, err := session.GetLanguageService(ctx, mainURI)
+	assert.NilError(t, err)
+	configuredProject := session.Snapshot().GetDefaultProject(mainURI)
+	assert.Assert(t, configuredProject != nil)
+	mappers := configuredProject.CommandLine.ContentMappers()
+	assert.Equal(t, len(mappers), 1)
+	assert.Equal(t, mappers[0].PackageDirectory, tspath.RootedDirectoryPath("/home/mapper"))
+	session.WaitForBackgroundTasks()
+	assert.Assert(t, utils.WatchesFile(packageJsonPath), "expected the mapper package manifest to be watched")
+
+	fixedManifest := contentmappertest.PackageJSON(contentmappertest.TransformingMapper)
+	assert.NilError(t, utils.FS().WriteFile(packageJsonPath, fixedManifest))
+	session.DidChangeWatchedFiles(ctx, []*lsproto.FileEvent{{
+		Uri:  lsproto.DocumentUri("file://" + packageJsonPath),
+		Type: lsproto.FileChangeTypeChanged,
+	}})
+
+	languageService, err := session.GetLanguageService(ctx, mainURI)
+	assert.NilError(t, err)
+	boxFile := languageService.GetProgram().GetSourceFile("/home/project/app.box")
+	assert.Assert(t, boxFile != nil, "expected app.box in the rebuilt program")
+	assert.Assert(t, strings.Contains(boxFile.Text(), "export const version = 7;"), "expected fixed mapper manifest to be reloaded: %q", boxFile.Text())
+}
+
 func TestContentMapperSupplementalFileClonedOnEdit(t *testing.T) {
 	t.Parallel()
 	files := map[string]any{

tsc/internal/tsoptions/contentmappers.go

@@ -15,8 +15,8 @@ import (
 	"github.com/microsoft/TypeScript/tsc/internal/vfs"
 )
 
-// resolveContentMapperManifest locates packageName in node_modules (walking up from the directory of
-// containingFile via node module resolution) and reads its package.json to produce the mapper's manifest
+// resolveContentMapperManifest locates packageName as a directory path relative to containingFile or in
+// node_modules (walking up via node module resolution) and reads its package.json to produce the mapper's manifest
 // and package directory. It never executes the package. On failure it returns a diagnostic describing why
 // the mapper could not be resolved; on success the diagnostic is nil.
 type contentMapperResolutionHost struct {

tsc/internal/tsoptions/contentmappers_test.go

@@ -270,3 +270,77 @@ func TestResolveContentMapperManifest(t *testing.T) {
 	_, _, diagnostic = resolveContentMapperManifest(NewDefaultParseConfigHost(fs), "/home/project/tsconfig.json", "bad-output-extension")
 	assert.Equal(t, diagnostic.Code(), diagnostics.The_typescript_contentMapper_outputExtensions_of_the_content_mapper_package_0_contains_an_invalid_mapping_from_1_to_2_Extensions_must_be_non_empty_and_begin_with_a.Code())
 }
+
+func TestResolveContentMapperManifestPaths(t *testing.T) {
+	t.Parallel()
+
+	for _, test := range []struct {
+		packageName      string
+		packageDirectory tspath.RootedDirectoryPath
+	}{
+		{".", "/home/project"},
+		{"..", "/home"},
+		{"./mapper", "/home/project/mapper"},
+		{"../mapper", "/home/mapper"},
+		{`.\mapper`, "/home/project/mapper"},
+		{`..\mapper`, "/home/mapper"},
+		{"/home/mapper", "/home/mapper"},
+		{`C:\mapper`, "C:/mapper"},
+	} {
+		t.Run(test.packageName, func(t *testing.T) {
+			t.Parallel()
+			files := map[string]string{
+				"/home/node_modules/unrelated/package.json": `{
+					"name": "unrelated",
+					"typescript": { "contentMapper": { "exec": ["run"] } }
+				}`,
+				"/home/package.json": `{"name": "unrelated"}`,
+			}
+			files[test.packageDirectory.ResolveFile("package.json").AsString()] = `{
+				"name": "mapper",
+				"typescript": { "contentMapper": { "exec": ["run"] } }
+			}`
+			containingFile := tspath.RootedFilePath("/home/project/tsconfig.json")
+			if test.packageName == `C:\mapper` {
+				files = map[string]string{
+					"C:/mapper/package.json": files["C:/mapper/package.json"],
+				}
+				containingFile = "C:/project/tsconfig.json"
+			}
+			fs := vfstest.FromMap(files, tspath.CaseSensitive)
+			for _, allowed := range []bool{false, true} {
+				host := &contentMapperTestParseConfigHost{ParseConfigHost: NewDefaultParseConfigHost(fs), allowed: allowed}
+				manifest, packageDirectory, diagnostic := resolveContentMapperManifest(host, containingFile, test.packageName)
+				assert.Equal(t, host.packageDirectory, test.packageDirectory)
+				if allowed {
+					assert.Assert(t, diagnostic == nil)
+					assert.Equal(t, packageDirectory, test.packageDirectory)
+					assert.Equal(t, manifest.Name, "mapper")
+					assert.DeepEqual(t, manifest.Exec, []string{"run"})
+				} else {
+					assert.Assert(t, diagnostic != nil)
+					assert.Equal(t, diagnostic.Code(), diagnostics.The_content_mapper_package_0_is_outside_the_open_workspace_and_will_not_be_loaded.Code())
+				}
+			}
+		})
+	}
+}
+
+func TestResolveContentMapperManifestMissingPaths(t *testing.T) {
+	t.Parallel()
+
+	for _, packageName := range []string{"./does-not-exist", "../does-not-exist", "/does-not-exist", `C:\does-not-exist`, "../no-manifest", "../file"} {
+		t.Run(packageName, func(t *testing.T) {
+			t.Parallel()
+			fs := vfstest.FromMap(map[string]string{
+				"/home/package.json":                        `{"name": "unrelated"}`,
+				"/home/node_modules/unrelated/package.json": `{"name": "unrelated"}`,
+				"/home/no-manifest/index.js":                "",
+				"/home/file":                                "",
+			}, tspath.CaseSensitive)
+			_, _, diagnostic := resolveContentMapperManifest(NewDefaultParseConfigHost(fs), "/home/project/tsconfig.json", packageName)
+			assert.Assert(t, diagnostic != nil)
+			assert.Equal(t, diagnostic.Code(), diagnostics.The_content_mapper_package_0_could_not_be_resolved.Code())
+		})
+	}
+}

tsc/internal/tsoptions/tsconfigparsing.go

@@ -25,13 +25,14 @@ import (
 )
 
 type extendsResult struct {
-	options             *parsedCompilerOptions
-	include             []any
-	exclude             []any
-	files               []any
-	contentMappers      []any
-	compileOnSave       bool
-	extendedSourceFiles collections.Set[tspath.RootedFilePath]
+	options                  *parsedCompilerOptions
+	include                  []any
+	exclude                  []any
+	files                    []any
+	contentMappers           []any
+	contentMappersConfigFile tspath.RootedFilePath
+	compileOnSave            bool
+	extendedSourceFiles      collections.Set[tspath.RootedFilePath]
 }
 
 type configFileSpecs struct {
@@ -85,10 +86,11 @@ func (e *ExtendedConfigCacheEntry) ExtendedFileNames() []tspath.RootedFilePath {
 }
 
 type parsedTsconfig struct {
-	raw                 any
-	options             *parsedCompilerOptions
-	typeAcquisition     *core.TypeAcquisition
-	extendedConfigPaths []tspath.RootedFilePath
+	raw                      any
+	options                  *parsedCompilerOptions
+	typeAcquisition          *core.TypeAcquisition
+	extendedConfigPaths      []tspath.RootedFilePath
+	contentMappersConfigFile tspath.RootedFilePath
 }
 
 type parsedCompilerOptions struct {
@@ -199,10 +201,11 @@ func parseOwnConfigOfJsonSourceFile(
 		))
 	}
 	return &parsedTsconfig{
-		raw:                 json,
-		options:             compilerOptions,
-		typeAcquisition:     typeAcquisition,
-		extendedConfigPaths: extendedConfigPaths,
+		raw:                      json,
+		options:                  compilerOptions,
+		typeAcquisition:          typeAcquisition,
+		extendedConfigPaths:      extendedConfigPaths,
+		contentMappersConfigFile: configFileName,
 	}, errors
 }
 
@@ -901,10 +904,11 @@ func parseOwnConfigOfJson(
 		errors = append(errors, err...)
 	}
 	parsedConfig := &parsedTsconfig{
-		raw:                 json,
-		options:             options,
-		typeAcquisition:     typeAcquisition,
-		extendedConfigPaths: extendedConfigPaths,
+		raw:                      json,
+		options:                  options,
+		typeAcquisition:          typeAcquisition,
+		extendedConfigPaths:      extendedConfigPaths,
+		contentMappersConfigFile: configFileName,
 	}
 	return parsedConfig, errors
 }
@@ -1087,6 +1091,7 @@ func parseConfig(
 			setPropertyValue("files")
 			if extendedRawMap, ok := extendsRaw.(*collections.OrderedMap[string, any]); ok && extendedRawMap.Has("contentMappers") {
 				result.contentMappers, _ = extendedRawMap.GetOrZero("contentMappers").([]any)
+				result.contentMappersConfigFile = extendedConfig.contentMappersConfigFile
 			}
 			if extendedRawMap, ok := extendsRaw.(*collections.OrderedMap[string, any]); ok && extendedRawMap.Has("compileOnSave") {
 				if compileOnSave, ok := extendedRawMap.GetOrZero("compileOnSave").(bool); ok {
@@ -1120,6 +1125,7 @@ func parseConfig(
 		}
 		if result.contentMappers != nil && !ownConfig.raw.(*collections.OrderedMap[string, any]).Has("contentMappers") {
 			ownConfig.raw.(*collections.OrderedMap[string, any]).Set("contentMappers", result.contentMappers)
+			ownConfig.contentMappersConfigFile = result.contentMappersConfigFile
 		}
 		if result.compileOnSave && !ownConfig.raw.(*collections.OrderedMap[string, any]).Has("compileOnSave") {
 			ownConfig.raw.(*collections.OrderedMap[string, any]).Set("compileOnSave", result.compileOnSave)
@@ -1398,9 +1404,12 @@ func parseJsonConfigFileContentWorker(
 	} else if len(contentMappers) > 0 {
 		// Resolve each mapper's package.json now so its name, version, and run command are available to
 		// everything downstream (diagnostics, build-info staleness) without executing anything.
-		containingFile := configFileName
+		containingFile := parsedConfig.contentMappersConfigFile
 		if containingFile == "" {
-			containingFile = basePathForFileNames.ResolveFile("tsconfig.json")
+			containingFile = configFileName
+			if containingFile == "" {
+				containingFile = basePathForFileNames.ResolveFile("tsconfig.json")
+			}
 		}
 		resolvedContentMappers := make([]*contentmapper.Mapper, 0, len(contentMappers))
 		for j, mapper := range contentMappers {