Update sourcemapPathTransform to also take the path to the sourcemap … (

#3617)

* Update sourcemapPathTransform to also take the path to the sourcemap file as a second argument

* update docs

* make test example make a little more sense

* Fix test and types, polish documentation

* Fix types again

Co-authored-by: Lukas Taegert-Atkinson <lukas.taegert-atkinson@tngtech.com>
Co-authored-by: Lukas Taegert-Atkinson <lukastaegert@users.noreply.github.com>

docs/999-big-list-of-options.md

@@ -670,19 +670,19 @@ The location of the generated bundle. If this is an absolute path, all the `sour
 `sourcemapFile` is not required if `output` is specified, in which case an output filename will be inferred by adding ".map"  to the output filename for the bundle.
 
 #### output.sourcemapPathTransform
-Type: `(sourcePath: string) => string`
+Type: `(relativeSourcePath: string, sourcemapPath: string) => string`
 
-A transformation to apply to each path in a sourcemap. For instance the following will change all paths to be relative to the `src` directory.
+A transformation to apply to each path in a sourcemap. `relativeSourcePath` is a relative path from the generated `.map` file to the corresponding source file while `sourcemapPath` is the fully resolved path of the generated sourcemap file.
 
 ```js
 import path from 'path';
 export default ({
   input: 'src/main',
   output: [{
     file: 'bundle.js',
-    sourcemapPathTransform: relativePath => {
-      // will transform e.g. "src/main.js" -> "main.js"
-      return path.relative('src', relativePath)
+    sourcemapPathTransform: (relativeSourcePath, sourcemapPath) => {
+      // will replace relative paths with absolute paths
+      return path.resolve(path.dirname(sourcemapPath), relativeSourcePath)
     },
     format: 'es',
     sourcemap: true

src/Chunk.ts

@@ -726,7 +726,7 @@ export default class Chunk {
 					const { sourcemapPathTransform } = options;
 
 					if (sourcemapPathTransform) {
-						const newSourcePath = sourcemapPathTransform(sourcePath);
+						const newSourcePath = sourcemapPathTransform(sourcePath, `${file}.map`);
 
 						if (typeof newSourcePath !== 'string') {
 							error(errFailedValidation(`sourcemapPathTransform function must return a string.`));

src/rollup/types.d.ts

@@ -478,6 +478,10 @@ export type InputOption = string | string[] | { [entryAlias: string]: string };
 export type ManualChunksOption = { [chunkAlias: string]: string[] } | GetManualChunk;
 export type ModuleSideEffectsOption = boolean | 'no-external' | string[] | HasModuleSideEffects;
 export type PreserveEntrySignaturesOption = false | 'strict' | 'allow-extension';
+export type SourcemapPathTransformOption = (
+	relativeSourcePath: string,
+	sourcemapPath: string
+) => string;
 
 export interface InputOptions {
 	acorn?: Object;
@@ -569,7 +573,7 @@ export interface OutputOptions {
 	sourcemap?: boolean | 'inline' | 'hidden';
 	sourcemapExcludeSources?: boolean;
 	sourcemapFile?: string;
-	sourcemapPathTransform?: (sourcePath: string) => string;
+	sourcemapPathTransform?: SourcemapPathTransformOption;
 	strict?: boolean;
 	systemNullSetters?: boolean;
 }
@@ -611,7 +615,7 @@ export interface NormalizedOutputOptions {
 	sourcemap: boolean | 'inline' | 'hidden';
 	sourcemapExcludeSources: boolean;
 	sourcemapFile: string | undefined;
-	sourcemapPathTransform: ((sourcePath: string) => string) | undefined;
+	sourcemapPathTransform: SourcemapPathTransformOption | undefined;
 	strict: boolean;
 	systemNullSetters: boolean;
 }

src/utils/options/normalizeOutputOptions.ts

@@ -5,7 +5,8 @@ import {
 	NormalizedInputOptions,
 	NormalizedOutputOptions,
 	OptionsPaths,
-	OutputOptions
+	OutputOptions,
+	SourcemapPathTransformOption
 } from '../../rollup/types';
 import { ensureArray } from '../ensureArray';
 import { errInvalidExportOptionValue, error, warnDeprecation } from '../error';
@@ -57,7 +58,7 @@ export function normalizeOutputOptions(
 		sourcemapExcludeSources: (config.sourcemapExcludeSources as boolean | undefined) || false,
 		sourcemapFile: config.sourcemapFile as string | undefined,
 		sourcemapPathTransform: config.sourcemapPathTransform as
-			| ((sourcePath: string) => string)
+			| SourcemapPathTransformOption
 			| undefined,
 		strict: (config.strict as boolean | undefined) ?? true,
 		systemNullSetters: (config.systemNullSetters as boolean | undefined) || false

test/sourcemaps/samples/transform-full-source-paths/_config.js

@@ -0,0 +1,17 @@
+const path = require('path');
+const assert = require('assert');
+
+module.exports = {
+	description: 'provides the full source map path when transforming source maps',
+	options: {
+		output: {
+			name: 'myModule',
+			file: path.join(__dirname, '_actual/bundle.js'),
+			sourcemapPathTransform: (relativeSourcePath, sourcemapPath) =>
+				path.resolve(path.dirname(sourcemapPath), relativeSourcePath)
+		}
+	},
+	test(code, map) {
+		assert.deepEqual(map.sources, [path.resolve(__dirname, 'main.js')]);
+	}
+};

test/sourcemaps/samples/transform-full-source-paths/main.js

@@ -0,0 +1 @@
+export default 42;