feat(vite-node): provide import.meta.resolve

packages/vite-node/src/client.ts

@@ -304,6 +304,24 @@ export class ViteNodeRunner {
       filename: __filename,
       dirname: __dirname,
     }
+    if (typeof import.meta.resolve !== 'undefined') {
+      // check if 2nd argument feature is available
+      let ok = false
+      try {
+        // old Node returns Promise
+        const testParent = await import.meta.resolve('.', new URL('./__test_parent__/', import.meta.url))
+        ok = typeof testParent === 'string' && testParent.endsWith('/__test_parent__/')
+      }
+      catch {
+        // old Node throws when invalid path
+      }
+      (meta as any).resolve = (specifier: string, parent?: string | URL) => {
+        if (!ok)
+          throw new Error('[vite-node] "--experimental-import-meta-resolve" is required to enable "import.meta.resolve"')
+        return import.meta.resolve(specifier, parent ?? href)
+      }
+    }
+
     const exports = Object.create(null)
     Object.defineProperty(exports, Symbol.toStringTag, {
       value: 'Module',

test/import-meta-resolve/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "@vitest/test-import-meta-resolve",
+  "type": "module",
+  "private": true,
+  "scripts": {
+    "test": "vitest"
+  },
+  "devDependencies": {
+    "vitest": "workspace:*"
+  }
+}

test/import-meta-resolve/test/basic.test.ts

@@ -0,0 +1,41 @@
+import { expect, test } from 'vitest'
+
+test('basic', () => {
+  // relative path
+  expect(
+    cleanDir(import.meta.resolve('../package.json')),
+  ).toMatchInlineSnapshot(`"__DIR__/test/import-meta-resolve/package.json"`)
+
+  // not throw in latest NodeJS
+  expect(cleanDir(import.meta.resolve('../no-such-file'))).toMatchInlineSnapshot(
+    `"__DIR__/test/import-meta-resolve/no-such-file"`,
+  )
+
+  // with 2nd argument `parent`
+  expect(
+    cleanDir(
+      import.meta.resolve('./package.json', new URL('..', import.meta.url)),
+    ),
+  ).toMatchInlineSnapshot(`"__DIR__/test/import-meta-resolve/package.json"`)
+
+  // node_module
+  expect(cleanDir(import.meta.resolve('vitest'))).toMatchInlineSnapshot(
+    `"__DIR__/packages/vitest/dist/index.js"`,
+  )
+
+  expect(() =>
+    cleanDir(import.meta.resolve('@vitest/not-such-module')),
+  ).toThrow(
+    expect.objectContaining({
+      message: expect.stringContaining(
+        'Cannot find package \'@vitest/not-such-module\' imported from',
+      ),
+    }),
+  )
+})
+
+// make output deterministic
+function cleanDir(out: string) {
+  const dir = new URL('../../..', import.meta.url).toString()
+  return out.replace(dir, '__DIR__/')
+}

test/import-meta-resolve/vitest.config.ts

@@ -0,0 +1,18 @@
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    poolOptions: {
+      threads: {
+        execArgv: ['--experimental-import-meta-resolve'],
+      },
+      forks: {
+        execArgv: ['--experimental-import-meta-resolve'],
+      },
+      vmThreads: {
+        // vmThreads already enables this flag
+        // execArgv: ['--experimental-import-meta-resolve'],
+      },
+    },
+  },
+})

test/vite-node/src/require-vite-node.cjs

@@ -0,0 +1,2 @@
+require('vite-node/client')
+require('vite-node/server')

test/vite-node/test/cjs.test.ts

@@ -0,0 +1,15 @@
+import { execFile } from 'node:child_process'
+import { fileURLToPath } from 'node:url'
+import { promisify } from 'node:util'
+import { it } from 'vitest'
+
+const execFileAsync = promisify(execFile)
+
+it('require vite-node', async () => {
+  // verify `import.meta.resolve` usage doesn't cause syntax error on vite-node cjs build
+  // since rollup replaces it with `undefined`
+  await execFileAsync(
+    'node',
+    [fileURLToPath(new URL('../src/require-vite-node.cjs', import.meta.url))],
+  )
+})