feat: add transform hook

Author: simonhaenisch

index.ts

@@ -4,6 +4,7 @@ import { CompilerOptions, findConfigFile, nodeModuleNameResolver, sys } from 'ty
 export const resolveTypescriptPaths = ({
 	tsConfigPath = findConfigFile('./', sys.fileExists),
 	absolute = true,
+	transform,
 }: Options = {}) => {
 	const { compilerOptions, outDir } = getTsConfig(tsConfigPath);
 
@@ -36,7 +37,13 @@ export const resolveTypescriptPaths = ({
 
 			const jsFileName = join(outDir, resolvedFileName.replace(/\.tsx?$/i, '.js'));
 
-			return absolute ? sys.resolvePath(jsFileName) : jsFileName;
+			let resolved = absolute ? sys.resolvePath(jsFileName) : jsFileName;
+
+			if (transform) {
+				resolved = transform(resolved);
+			}
+
+			return resolved;
 		},
 	};
 };
@@ -70,6 +77,12 @@ export interface Options {
 	 * Whether to resolve to absolute paths or not; defaults to `true`.
 	 */
 	absolute?: boolean;
+
+	/**
+	 * If the plugin successfully resolves a path, this function allows you to
+	 * hook into the process and transform that path before it is returned.
+	 */
+	transform?(path: string): string;
 }
 
 interface TsConfig {

readme.md

@@ -54,6 +54,7 @@ export default {
 
 * **`tsConfigPath`:** Custom path to your `tsconfig.json`. Use this if the plugin can't seem to find the correct one by itself.
 * **`absolute`:** Whether to resolve to absolute paths or not; defaults to `true`.
+* **`transform`:** If the plugin successfully resolves a path, this function allows you to hook into the process and transform that path before it is returned.
 
 ## License
 

test/index.js

@@ -4,7 +4,11 @@ const { strictEqual } = require('assert');
 const { resolve, join } = require('path');
 const { resolveTypescriptPaths } = require('../dist');
 
+const transform = path => path.replace(/\.js$/i, '.cjs.js');
+
 const plugin = resolveTypescriptPaths({ tsConfigPath: resolve(__dirname, 'tsconfig.json') });
+const pluginNonAbs = resolveTypescriptPaths({ tsConfigPath: resolve(__dirname, 'tsconfig.json'), absolute: false });
+const pluginTransform = resolveTypescriptPaths({ tsConfigPath: resolve(__dirname, 'tsconfig.json'), transform });
 
 try {
 	strictEqual(plugin.resolveId('@asdf', ''), null);
@@ -13,6 +17,9 @@ try {
 	strictEqual(plugin.resolveId('@bar/foo', ''), join(__dirname, 'bar', 'foo.js'));
 	strictEqual(plugin.resolveId('@js', ''), join(__dirname, 'js', 'index.js'));
 
+	strictEqual(pluginNonAbs.resolveId('@foobar', ''), join('test', 'foo', 'bar.js'));
+
+	strictEqual(pluginTransform.resolveId('@foobar', ''), join(__dirname, 'foo', 'bar.cjs.js'));
 	console.log('PASSED');
 } catch (error) {
 	throw error;