use compiled extension in loaded responseURL

Author: andrew0

src/hooks/hooks.mts

@@ -6,7 +6,7 @@ import type {
   LoadHook,
   ResolveHook,
 } from 'node:module'
-import { resolve as pathResolve } from 'node:path'
+import { extname, resolve as pathResolve } from 'node:path'
 import { fileURLToPath, pathToFileURL } from 'node:url'
 import { format } from 'node:util'
 import { MessagePort } from 'node:worker_threads'
@@ -92,10 +92,20 @@ export const load: LoadHook = async (url, context, nextLoad) => {
     }
     const format = classifyModule(inputFile)
     hookedCJS ||= format === 'commonjs'
+    const responseURL = new URL(url)
+    const sourceExtension = extname(responseURL.pathname)
+    const compiledExtension = extname(fileName)
+    /* c8 ignore start */
+    responseURL.pathname =
+      (sourceExtension
+        ? responseURL.pathname.slice(0, -sourceExtension.length)
+        : responseURL.pathname) + compiledExtension
+    /* c8 ignore stop */
     return {
       source: await readFile(fileName, 'utf8'),
       shortCircuit: true,
       format,
+      responseURL: String(responseURL),
     }
   }
 

test/hooks/hooks.ts

@@ -128,21 +128,29 @@ t.test('load', async t => {
   })
 
   t.test('do a compile, with diagnostics', async t => {
-    const dir = t.testdir({ file: 'contents' })
+    const dir = t.testdir({ 'file-compiled.js': 'contents' })
     const nextLoad = (url: string, context?: LoadHookContext) => ({
       url,
       ...context,
     })
     delete MockDaemonClient.compileRequest
     MockDaemonClient.compileResponse = {
-      fileName: resolve(dir, 'file'),
+      fileName: resolve(dir, 'file-compiled.js'),
       diagnostics: ['diagnostics'],
     }
-    t.strictSame(await hooks.load(import.meta.url, {}, nextLoad), {
-      source: 'contents',
-      shortCircuit: true,
-      format: 'module',
-    })
+    t.strictSame(
+      await hooks.load(
+        String(pathToFileURL(resolve(dir, 'file.ts'))),
+        {},
+        nextLoad
+      ),
+      {
+        source: 'contents',
+        shortCircuit: true,
+        format: 'module',
+        responseURL: String(pathToFileURL(resolve(dir, 'file.js'))),
+      }
+    )
     t.strictSame(stderrWrites, ['diagnostics\n'])
     stderrWrites.length = 0
   })
@@ -212,6 +220,9 @@ t.test('load', async t => {
       format: 'commonjs',
       source: readFileSync(resolve(dir, 'project/foo.js'), 'utf8'),
       shortCircuit: true,
+      responseURL: String(
+        pathToFileURL(resolve(dir, 'project/foo.js'))
+      ),
     })
     const outRes = await hooks.load(
       String(pathToFileURL(resolve(dir, 'outside.js'))),