Help on Windows Support about esbuild-node-loader

[userquin]

Seems using relative paths working, with absolute paths there is no way man (I'll try one last time to see if there's any luck):

F:\work\projects\quini\GitHub\antfu\esbuild-node-loader>pnpm run test

> [email protected] test F:\work\projects\quini\GitHub\antfu\esbuild-node-loader
> node --experimental-loader ./loader.mjs test/entry.ts

(node:23624) ExperimentalWarning: --experimental-loader is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
• • • • • •   (6 / 6)

  Total:     6
  Passed:    6
  Skipped:   0
  Duration:  1146.71ms

test/entry.ts changes

@@ -1,12 +1,20 @@
 import assert from 'assert'
 import { test } from 'uvu'
 import execa from 'execa'
+import { relative } from 'path'
+
+const cwd = process.cwd()
+function relativize(path: string) {
+  const url = relative(cwd, path)
+  // console.log(`FROM ${path} => ${url}`)
+  return `./${url}`
+}
 
 test('register', async() => {
   const { stdout } = await execa('node', [
     '--experimental-loader',
-    `${process.cwd()}/loader.mjs`,
-    `${process.cwd()}/test/fixture.ts`,
+    relativize(`${cwd}/loader.mjs`),
+    relativize(`${cwd}/test/fixture.ts`),
   ])
   assert(stdout === 'text')
 })
@@ -14,8 +22,8 @@
 test('register2', async() => {
   const { stdout } = await execa('node', [
     '--experimental-loader',
-    `${process.cwd()}/loader.mjs`,
-    `${process.cwd()}/test/fixture.arrowFunction.ts`,
+    relativize(`${cwd}/loader.mjs`),
+    relativize(`${cwd}/test/fixture.arrowFunction.ts`),
   ])
   assert(stdout === 'hello from ts')
 })
@@ -23,8 +31,8 @@
 test('register3', async() => {
   const { stdout } = await execa('node', [
     '--experimental-loader',
-    `${process.cwd()}/loader.mjs`,
-    `${process.cwd()}/test/fixture.import.ts`,
+    relativize(`${cwd}/loader.mjs`),
+    relativize(`${cwd}/test/fixture.import.ts`),
   ])
   assert(stdout === 'export')
 })
@@ -32,8 +40,8 @@
 test('register cjs', async() => {
   const { stdout } = await execa('node', [
     '--experimental-loader',
-    `${process.cwd()}/loader.mjs`,
-    `${process.cwd()}/test/fixture.cjs.ts`,
+    relativize(`${cwd}/loader.mjs`),
+    relativize(`${cwd}/test/fixture.cjs.ts`),
   ])
   assert(stdout === 'fs imported')
 })
@@ -41,8 +49,8 @@
 test('package type module', async() => {
   const { stdout } = await execa('node', [
     '--experimental-loader',
-    `${process.cwd()}/loader.mjs`,
-    `${process.cwd()}/test/fixture-type-module/index.js`,
+    relativize(`${cwd}/loader.mjs`),
+    relativize(`${cwd}/test/fixture-type-module/index.js`),
   ])
   assert(stdout === 'foo')
 })
@@ -50,8 +58,8 @@
 test('import type module', async() => {
   const { stdout } = await execa('node', [
     '--experimental-loader',
-    `${process.cwd()}/loader.mjs`,
-    `${process.cwd()}/test/import-mjs/index.js`,
+    relativize(`${cwd}/loader.mjs`),
+    relativize(`${cwd}/test/import-mjs/index.js`),
   ])
   assert(stdout === 'foo')
 })

loader.mjs changes

@@ -1,8 +1,16 @@
 import { URL, pathToFileURL, fileURLToPath } from 'url'
 import { transformSync } from 'esbuild'
 import fs from 'fs'
+import { relative } from 'path'
 
-const baseURL = pathToFileURL(`${process.cwd()}/`).href
+const cwd = process.cwd()
+function relativize(path) {
+  const url = relative(cwd, path)
+  //console.log(`FROM ${path} => ${url}`)
+  return `./${url}`
+}
+
+const baseURL = pathToFileURL(relativize(`${cwd}/`)).href
 const isWindows = process.platform === "win32"
 
 const extensionsRegex = /\.ts$/
@@ -46,12 +54,12 @@
   const { url, format } = context
 
   if (extensionsRegex.test(url)) {
-    let filename = fileURLToPath(url)
-    if (isWindows)
-      filename = filename.slice(1)
+    // let filename = fileURLToPath(url)
+    // if (isWindows)
+    //   filename = filename.slice(1)
 
     const { code: js, warnings, map: jsSourceMap } = transformSync(source.toString(), {
-      sourcefile: filename,
+      sourcefile: url,
       sourcemap: 'both',
       loader: 'ts',
       target: 'esnext',

[userquin]

@antfu Working, just modify transformSource from loader.mjs:

Adjust filename assigment:

    let filename = url
    if (!isWindows)
      filename = fileURLToPath(url)

To make the tests working you need to use relativize from previous comment.

transformSource code:

export function transformSource(source, context, defaultTransformSource) {
  const { url, format } = context

  if (extensionsRegex.test(url)) {
    let filename = url
    if (!isWindows)
      filename = fileURLToPath(url)

    const { code: js, warnings, map: jsSourceMap } = transformSync(source.toString(), {
      sourcefile: filename,
      sourcemap: 'both',
      loader: 'ts',
      target: 'esnext',
      format: format === 'module' ? 'esm' : 'cjs',
    })

    if (warnings && warnings.length > 0) {
      for (const warning of warnings) {
        console.log(warning.location)
        console.log(warning.text)
      }
    }

    return {
      source: js,
    }
  }

  // Let Node.js handle all other sources.
  return defaultTransformSource(source, context, defaultTransformSource)
}

[userquin]

Maybe you need to check if script is provided with absolute path and then relativize from cwd: using esno I've never seen provide scripts with absolute paths, always with relative paths, I think if also working previous fix on linux/macosx, just include a warning/hint for windows users to use always relative paths to root directory.

[antfu]

Ideally I think we would like to have absolute path working as well

[userquin]

Found these 2 issues, I have tried with no luck:

• nodejs/node#31710
• vitejs/vite#1487