[heft-sass-plugin] Emit declaration source maps for generated typings

common/changes/@rushstack/heft-localization-typings-plugin/feature-typings-generator-declaration-maps_2026-07-28-20-47-38.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Add opt-in declaration source map generation so editors can resolve go-to-definition from generated typings to the original source file.",
+      "type": "minor",
+      "packageName": "@rushstack/heft-localization-typings-plugin"
+    }
+  ],
+  "packageName": "@rushstack/heft-localization-typings-plugin",
+  "email": "mdelgaudio_microsoft@users.noreply.github.com"
+}

common/changes/@rushstack/heft-sass-plugin/feature-heft-sass-plugin-declaration-maps_2026-07-29-20-30-00.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/heft-sass-plugin",
+      "comment": "Add an opt-in \"generateDeclarationMaps\" option that emits a \".d.ts.map\" beside each generated typings file, so that \"go to definition\" on a CSS module class resolves to the rule in the stylesheet instead of the generated typings.",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@rushstack/heft-sass-plugin"
+}

common/changes/@rushstack/localization-utilities/feature-typings-generator-declaration-maps_2026-07-28-20-47-38.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Add opt-in declaration source map generation so editors can resolve go-to-definition from generated typings to the original source file.",
+      "type": "minor",
+      "packageName": "@rushstack/localization-utilities"
+    }
+  ],
+  "packageName": "@rushstack/localization-utilities",
+  "email": "mdelgaudio_microsoft@users.noreply.github.com"
+}

common/changes/@rushstack/typings-generator/feature-declaration-map-decoding_2026-07-29-20-30-00.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/typings-generator",
+      "comment": "Support multiple sources in \"serializeDeclarationMap\", and add \"decodeMappings\" and \"originalPositionFor\" so that generators which compile their input can translate positions back to the original file.",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@rushstack/typings-generator"
+}

common/changes/@rushstack/typings-generator/feature-typings-generator-declaration-maps_2026-07-28-20-47-38.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Add opt-in declaration source map generation so editors can resolve go-to-definition from generated typings to the original source file.",
+      "type": "minor",
+      "packageName": "@rushstack/typings-generator"
+    }
+  ],
+  "packageName": "@rushstack/typings-generator",
+  "email": "mdelgaudio_microsoft@users.noreply.github.com"
+}

common/config/subspaces/default/repo-state.json

@@ -1,5 +1,5 @@
 // DO NOT MODIFY THIS FILE MANUALLY BUT DO COMMIT IT. It is generated and used by Rush.
 {
-  "pnpmShrinkwrapHash": "288ee1cccceca305122bc3d4b1eb550efbcb2a0b",
+  "pnpmShrinkwrapHash": "121b6455d44723fc7bdb38b7d038aae935a28bd1",
   "preferredVersionsHash": "029c99bd6e65c5e1f25e2848340509811ff9753c"
 }

common/reviews/api/localization-utilities.api.md

@@ -5,6 +5,7 @@
 ```ts
 
 import { IExportAsDefaultOptions } from '@rushstack/typings-generator';
+import type { ISourcePosition } from '@rushstack/typings-generator';
 import type { ITerminal } from '@rushstack/terminal';
 import { ITypingsGeneratorBaseOptions } from '@rushstack/typings-generator';
 import { NewlineKind } from '@rushstack/node-core-library';
@@ -31,6 +32,7 @@ export interface ILocalizationFile {
 export interface ILocalizedString {
     // (undocumented)
     comment?: string;
+    sourcePosition?: ISourcePosition;
     // (undocumented)
     value: string;
 }

common/reviews/api/typings-generator.api.md

@@ -6,6 +6,29 @@
 
 import { ITerminal } from '@rushstack/terminal';
 
+// @public
+export function decodeMappings(mappings: string): IDecodedSegment[][];
+
+// @public
+export interface IDeclarationMapping {
+    generatedColumn: number;
+    generatedLine: number;
+    sourceIndex?: number;
+    sourcePosition: ISourcePosition;
+}
+
+// @public
+export interface IDecodedSegment {
+    // (undocumented)
+    generatedColumn: number;
+    // (undocumented)
+    sourceColumn?: number;
+    // (undocumented)
+    sourceIndex?: number;
+    // (undocumented)
+    sourceLine?: number;
+}
+
 // @public (undocumented)
 export interface IExportAsDefaultOptions {
     // @deprecated (undocumented)
@@ -15,6 +38,20 @@ export interface IExportAsDefaultOptions {
     valueDocumentationComment?: string;
 }
 
+// @public
+export interface IGeneratedTypings {
+    declarationMappings?: readonly IDeclarationMapping[];
+    typingsData: string;
+}
+
+// @public
+export interface ISourcePosition {
+    // (undocumented)
+    column: number;
+    // (undocumented)
+    line: number;
+}
+
 // @public (undocumented)
 export interface IStringValuesTypingsGeneratorBaseOptions {
     exportAsDefault?: boolean | IExportAsDefaultOptions;
@@ -36,6 +73,7 @@ export interface IStringValueTyping {
     comment?: string;
     // (undocumented)
     exportName: string;
+    sourcePosition?: ISourcePosition;
 }
 
 // @public (undocumented)
@@ -47,6 +85,7 @@ export interface IStringValueTypings {
 
 // @public (undocumented)
 export interface ITypingsGeneratorBaseOptions {
+    generateDeclarationMaps?: boolean;
     // (undocumented)
     generatedTsFolder: string;
     // (undocumented)
@@ -81,9 +120,19 @@ export interface ITypingsGeneratorOptionsWithoutReadFile<TTypingsResult = string
     parseAndGenerateTypings: (fileContents: TFileContents, filePath: string, relativePath: string) => TTypingsResult | Promise<TTypingsResult>;
 }
 
+// @public
+export function originalPositionFor(decoded: readonly IDecodedSegment[][], line: number, column: number): {
+    sourceIndex: number;
+    line: number;
+    column: number;
+} | undefined;
+
 // @public (undocumented)
 export type ReadFile<TFileContents = string> = (filePath: string, relativePath: string) => Promise<TFileContents> | TFileContents;
 
+// @public
+export function serializeDeclarationMap(mappings: readonly IDeclarationMapping[], generatedFileName: string, sources: string | readonly string[], generatedLineOffset: number): string;
+
 // @public
 export class StringValuesTypingsGenerator<TFileContents = string> extends TypingsGenerator<TFileContents> {
     constructor(options: TFileContents extends string ? IStringValuesTypingsGeneratorOptions<TFileContents> : never);
@@ -92,15 +141,15 @@ export class StringValuesTypingsGenerator<TFileContents = string> extends Typing
 
 // @public
 export class TypingsGenerator<TFileContents = string> {
-    constructor(options: TFileContents extends string ? ITypingsGeneratorOptions<string | undefined, TFileContents> : never);
-    constructor(options: ITypingsGeneratorOptionsWithCustomReadFile<string | undefined, TFileContents>);
+    constructor(options: TFileContents extends string ? ITypingsGeneratorOptions<string | IGeneratedTypings | undefined, TFileContents> : never);
+    constructor(options: ITypingsGeneratorOptionsWithCustomReadFile<string | IGeneratedTypings | undefined, TFileContents>);
     generateTypingsAsync(relativeFilePaths?: string[]): Promise<void>;
     // (undocumented)
     getOutputFilePaths(relativePath: string): string[];
     readonly ignoredFileGlobs: readonly string[];
     readonly inputFileGlob: string;
     // (undocumented)
-    protected readonly _options: ITypingsGeneratorOptionsWithCustomReadFile<string | undefined, TFileContents>;
+    protected readonly _options: ITypingsGeneratorOptionsWithCustomReadFile<string | IGeneratedTypings | undefined, TFileContents>;
     registerDependency(consumer: string, rawDependency: string): void;
     // (undocumented)
     runWatcherAsync(): Promise<void>;

heft-plugins/heft-localization-typings-plugin/src/LocalizationTypingsPlugin.ts

@@ -42,6 +42,15 @@ export interface ILocalizationTypingsPluginOptions {
    * An array of string names to ignore when generating typings.
    */
   stringNamesToIgnore?: string[];
+
+  /**
+   * If true, a `.d.ts.map` file is emitted next to each generated `.d.ts` file. This allows editors
+   * to resolve "go to definition" on a localized string to its declaration in the source
+   * localization file, instead of to the generated typings.
+   *
+   * @defaultValue false
+   */
+  generateDeclarationMaps?: boolean;
 }
 
 const PLUGIN_NAME: 'localization-typings-plugin' = 'localization-typings-plugin';

heft-plugins/heft-localization-typings-plugin/src/schemas/heft-localization-typings-plugin.schema.json

@@ -80,6 +80,11 @@
       "items": {
         "type": "string"
       }
+    },
+
+    "generateDeclarationMaps": {
+      "type": "boolean",
+      "description": "If true, a \".d.ts.map\" file is emitted next to each generated \".d.ts\" file, allowing editors to resolve \"go to definition\" to the source localization file instead of the generated typings."
     }
   }
 }

heft-plugins/heft-sass-plugin/package.json

@@ -47,6 +47,7 @@
   },
   "dependencies": {
     "@rushstack/node-core-library": "workspace:*",
+    "@rushstack/typings-generator": "workspace:*",
     "@types/tapable": "1.0.6",
     "postcss": "~8.5.10",
     "postcss-modules": "~6.0.0",