fix(esm+tsconfig): allow mapped ts files in esm mode

packages/playwright-test/src/experimentalLoader.ts

@@ -23,7 +23,7 @@ import { transformHook, resolveHook, belongsToNodeModules } from './transform';
 async function resolve(specifier: string, context: { parentURL?: string }, defaultResolve: Function) {
   if (context.parentURL && context.parentURL.startsWith('file://')) {
     const filename = url.fileURLToPath(context.parentURL);
-    const resolved = resolveHook(filename, specifier);
+    const resolved = resolveHook(true, filename, specifier);
     if (resolved !== undefined)
       specifier = url.pathToFileURL(resolved).toString();
   }

packages/playwright-test/src/transform.ts

@@ -93,7 +93,7 @@ const scriptPreprocessor = process.env.PW_TEST_SOURCE_TRANSFORM ?
   require(process.env.PW_TEST_SOURCE_TRANSFORM) : undefined;
 const builtins = new Set(Module.builtinModules);
 
-export function resolveHook(filename: string, specifier: string): string | undefined {
+export function resolveHook(isModule: boolean, filename: string, specifier: string): string | undefined {
   if (builtins.has(specifier))
     return;
   const isTypeScript = filename.endsWith('.ts') || filename.endsWith('.tsx');
@@ -133,11 +133,21 @@ export function resolveHook(filename: string, specifier: string): string | undef
         if (value.includes('*'))
           candidate = candidate.replace('*', matchedPartOfSpecifier);
         candidate = path.resolve(tsconfig.absoluteBaseUrl, candidate.replace(/\//g, path.sep));
-        for (const ext of ['', '.js', '.ts', '.mjs', '.cjs', '.jsx', '.tsx', '.cjs', '.mts', '.cts']) {
-          if (fs.existsSync(candidate + ext)) {
+        if (isModule) {
+          const transformed = js2ts(candidate);
+          if (transformed || fs.existsSync(candidate)) {
             if (keyPrefix.length > longestPrefixLength) {
               longestPrefixLength = keyPrefix.length;
-              pathMatchedByLongestPrefix = candidate;
+              pathMatchedByLongestPrefix = transformed || candidate;
+            }
+          }
+        } else {
+          for (const ext of ['', '.js', '.ts', '.mjs', '.cjs', '.jsx', '.tsx', '.cjs', '.mts', '.cts']) {
+            if (fs.existsSync(candidate + ext)) {
+              if (keyPrefix.length > longestPrefixLength) {
+                longestPrefixLength = keyPrefix.length;
+                pathMatchedByLongestPrefix = candidate;
+              }
             }
           }
         }
@@ -146,13 +156,17 @@ export function resolveHook(filename: string, specifier: string): string | undef
     if (pathMatchedByLongestPrefix)
       return pathMatchedByLongestPrefix;
   }
-  if (specifier.endsWith('.js')) {
-    const resolved = path.resolve(path.dirname(filename), specifier);
-    if (resolved.endsWith('.js')) {
-      const tsResolved = resolved.substring(0, resolved.length - 3) + '.ts';
-      if (!fs.existsSync(resolved) && fs.existsSync(tsResolved))
-        return tsResolved;
-    }
+
+  if (isModule)
+    return js2ts(path.resolve(path.dirname(filename), specifier));
+}
+
+export function js2ts(resolved: string): string | undefined {
+  const match = resolved.match(/(.*)(\.js|\.jsx|\.mjs)$/);
+  if (match) {
+    const tsResolved = match[1] + match[2].replace('j', 't');
+    if (!fs.existsSync(resolved) && fs.existsSync(tsResolved))
+      return tsResolved;
   }
 }
 
@@ -198,7 +212,7 @@ export function installTransform(): () => void {
   const originalResolveFilename = (Module as any)._resolveFilename;
   function resolveFilename(this: any, specifier: string, parent: Module, ...rest: any[]) {
     if (!reverted && parent) {
-      const resolved = resolveHook(parent.filename, specifier);
+      const resolved = resolveHook(false, parent.filename, specifier);
       if (resolved !== undefined)
         specifier = resolved;
     }

tests/playwright-test/esm.spec.ts

@@ -109,7 +109,7 @@ test('should respect path resolver in experimental mode', async ({ runInlineTest
       },
     }`,
     'a.test.ts': `
-      import { foo } from 'util/b.ts';
+      import { foo } from 'util/b.js';
       const { test } = pwt;
       test('check project name', ({}, testInfo) => {
         expect(testInfo.project.name).toBe(foo);