feat!: tests now run as ESM modules

`import.meta` is defined.

`new URL('./package.json', import.meta.url)` works now if the file is in the `--assets` folder (defaults to process.cwd())

mocks/sw/sw.config.mjs

@@ -1,10 +1,13 @@
-const path = require('path')
+import path from 'path'
+import { fileURLToPath } from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
 export default {
   buildSWConfig: {
     inject: [path.join(__dirname, 'sw-globals.js')],
   },
   afterTests: () => {
     console.log('AFTER')
-  }
+  },
 }

mocks/sw/sw.function.config.mjs

@@ -1,4 +1,7 @@
-const path = require('path')
+import path from 'path'
+import { fileURLToPath } from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
 export default function () {
   return {
@@ -7,6 +10,6 @@ export default function () {
     },
     afterTests: () => {
       console.log('AFTER')
-    }
+    },
   }
 }

mocks/sw/sw.promise.config.mjs

@@ -1,10 +1,13 @@
-const path = require('path')
+import path from 'path'
+import { fileURLToPath } from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
 export default Promise.resolve({
   buildSWConfig: {
     inject: [path.join(__dirname, 'sw-globals.js')],
   },
   afterTests: () => {
     console.log('AFTER')
-  }
+  },
 })

mocks/test.mocha.js

@@ -1,6 +1,6 @@
 /* eslint-disable no-undef */
 // eslint-disable-next-line strict
-const { is } = require('uvu/assert')
+const { is, ok } = require('uvu/assert')
 const debug = require('debug')('app')
 const { good, bad } = require('./lib')
 
@@ -26,5 +26,9 @@ describe('Array', () => {
     it('should return "bad"', async () => {
       is(await bad(), 'bad')
     })
+
+    it('should has import.meta', async () => {
+      ok(import.meta.url)
+    })
   })
 })

mocks/tinybench.js

@@ -0,0 +1,37 @@
+import { Bench } from 'tinybench'
+
+const bench = new Bench({ time: 100 })
+
+bench
+  .add('switch 1', () => {
+    let a = 1
+    let b = 2
+    const c = a
+    a = b
+    b = c
+  })
+  .add('switch 2', () => {
+    let a = 1
+    let b = 10
+    a = b + a
+    b = a - b
+    a = b - a
+  })
+
+await bench.run()
+
+console.table(
+  bench.tasks.map(({ name, result }) => ({
+    'Task Name': name,
+    'Average Time (ps)': result?.mean * 1000,
+    'Variance (ps)': result?.variance * 1000,
+  }))
+)
+
+// Output:
+// ┌─────────┬────────────┬────────────────────┬────────────────────┐
+// │ (index) │ Task Name  │ Average Time (ps)  │   Variance (ps)    │
+// ├─────────┼────────────┼────────────────────┼────────────────────┤
+// │    0    │ 'switch 1' │ 1.8458325710527104 │ 1.2113875253341617 │
+// │    1    │ 'switch 2' │ 1.8746935152109603 │ 1.2254725890767446 │
+// └─────────┴────────────┴────────────────────┴────────────────────┘

mocks/tinybench2.js

@@ -0,0 +1,37 @@
+import { Bench } from 'tinybench'
+
+const bench = new Bench({ time: 100 })
+
+bench
+  .add('switch 1', () => {
+    let a = 1
+    let b = 2
+    const c = a
+    a = b
+    b = c
+  })
+  .add('switch 2', () => {
+    let a = 1
+    let b = 10
+    a = b + a
+    b = a - b
+    a = b - a
+  })
+
+await bench.run()
+
+console.table(
+  bench.tasks.map(({ name, result }) => ({
+    'Task Name': name,
+    'Average Time (ps)': result?.mean * 1000,
+    'Variance (ps)': result?.variance * 1000,
+  }))
+)
+
+// Output:
+// ┌─────────┬────────────┬────────────────────┬────────────────────┐
+// │ (index) │ Task Name  │ Average Time (ps)  │   Variance (ps)    │
+// ├─────────┼────────────┼────────────────────┼────────────────────┤
+// │    0    │ 'switch 1' │ 1.8458325710527104 │ 1.2113875253341617 │
+// │    1    │ 'switch 2' │ 1.8746935152109603 │ 1.2254725890767446 │
+// └─────────┴────────────┴────────────────────┴────────────────────┘

package.json

@@ -91,6 +91,7 @@
     "lint-staged": "^13.2.2",
     "mocha": "^10.2.0",
     "simple-git-hooks": "^2.8.1",
+    "tinybench": "^2.4.0",
     "typescript": "^5.0.4",
     "uvu": "^0.5.6",
     "zora": "^5.2.0"

src/runner-mocha.js

@@ -80,7 +80,9 @@ class MochaRunner extends Runner {
     return build(
       this,
       {},
-      `require('${require.resolve('./setup-mocha.js').replace(/\\/g, '/')}')`,
+      `await import('${require
+        .resolve('./setup-mocha.js')
+        .replace(/\\/g, '/')}')`,
       mode
     )
   }

src/runner-tape.js

@@ -39,7 +39,9 @@ class TapeRunner extends Runner {
         plugins: [plugin],
         inject: [path.join(__dirname, 'node-globals-buffer.js')],
       },
-      `require('${require.resolve('./setup-tape.js').replace(/\\/g, '/')}')`,
+      `await import('${require
+        .resolve('./setup-tape.js')
+        .replace(/\\/g, '/')}')`,
       mode
     )
   }

src/runner.js

@@ -212,6 +212,8 @@ export class Runner {
         'Uncaught exception happened within the page. Run with --debug.'
       )
     })
+
+    await this.page.waitForLoadState('domcontentloaded')
     return this.page
   }
 
@@ -231,7 +233,7 @@ export class Runner {
 
     switch (this.options.mode) {
       case 'main': {
-        await page.addScriptTag({ url: outName })
+        await page.addScriptTag({ url: outName, type: 'module' })
         break
       }
       case 'worker': {

src/utils/index.js

@@ -269,7 +269,7 @@ export async function getPw(browserName) {
  */
 export function addWorker(filePath) {
   return `
-const w = new Worker("${filePath}");
+const w = new Worker("${filePath}", { type: "module" });
 w.onmessage = function(e) {
     if(e.data.pwRunEnded) {
         self.PW_TEST.end(e.data.pwRunFailed)
@@ -340,24 +340,26 @@ export async function build(runner, config = {}, tmpl = '', mode = 'bundle') {
 
   // main script template
   let infileContent = `
-'use strict'
-require('${sourceMapSupport.replace(/\\/g, '/')}').install();
+import { install } from '${sourceMapSupport.replace(/\\/g, '/')}'
+install()
 process.env = ${JSON.stringify(runner.env)}
 
 ${tmpl}
 
-${runner.tests.map((t) => `require('${t.replace(/\\/g, '/')}')`).join('\n')}
+${runner.tests
+  .map((t) => `await import('${t.replace(/\\/g, '/')}')`)
+  .join('\n')}
 `
 
   // before script template
   if (mode === 'before' && runner.options.before) {
     infileContent = `
-'use strict'
-require('${sourceMapSupport.replace(/\\/g, '/')}').install();
+import { install } from '${sourceMapSupport.replace(/\\/g, '/')}'
+install()
 process.env = ${JSON.stringify(runner.env)}
 
-require('${require.resolve('../static/setup.js').replace(/\\/g, '/')}')
-require('${require
+await import('${require.resolve('../static/setup.js').replace(/\\/g, '/')}')
+await import('${require
       .resolve(path.join(runner.options.cwd, runner.options.before))
       .replace(/\\/g, '/')}')
 `
@@ -391,6 +393,8 @@ require('${require
     // sourceRoot: runner.dir,
     bundle: true,
     sourcemap: 'inline',
+    platform: 'browser',
+    format: 'esm',
     plugins: [nodePlugin, watchPlugin],
     outfile: outPath,
     inject: [path.join(__dirname, 'inject-process.js')],

test.js

@@ -1,21 +1,21 @@
 import fs from 'fs'
 import path from 'path'
 import { ok, is } from 'uvu/assert'
-import { execa } from 'execa'
+import { execa, execaSync } from 'execa'
 
 describe('mocha', function () {
   it('basic', async () => {
     const proc = await execa('./cli.js', ['mocks/test.mocha.js'])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
   })
 
   it('coverage', async () => {
     const proc = await execa('./cli.js', ['mocks/test.mocha.js', '--cov'])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
 
     const cov = JSON.parse(
       // eslint-disable-next-line unicorn/prefer-json-parse-buffer
@@ -33,7 +33,7 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
 
     const cov = JSON.parse(
       // eslint-disable-next-line unicorn/prefer-json-parse-buffer
@@ -50,7 +50,7 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
   })
 
   it('coverage with cwd', async () => {
@@ -62,7 +62,7 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
 
     const cov = JSON.parse(
       // eslint-disable-next-line unicorn/prefer-json-parse-buffer
@@ -78,15 +78,15 @@ describe('mocha', function () {
     })
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
     ok(proc.stdout.includes('app test pass'), 'debug output')
   })
 
   it('incognito', async () => {
     const proc = await execa('./cli.js', ['mocks/test.mocha.js', '--incognito'])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
   })
 
   it('mode:worker', async () => {
@@ -97,25 +97,26 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
   })
 
   it('mocha extension', async () => {
     const proc = await execa('./cli.js', ['mocks/test.mocha.js', '--extension'])
     is(proc.exitCode, 0, 'exit code')
-    ok(proc.stdout.includes('5 passing'), 'process stdout')
+    ok(proc.stdout.includes('6 passing'), 'process stdout')
   })
 
-  it('sw', async () => {
-    const proc = await execa('./cli.js', [
+  it('sw', () => {
+    const proc = execaSync('./cli.js', [
       'mocks/sw/sw-test.js',
       '--sw',
       'mocks/sw/sw.js',
       '--config',
-      'mocks/sw/sw.config.js',
+      'mocks/sw/sw.config.cjs',
     ])
 
     is(proc.exitCode, 0, 'exit code')
+    ok(proc.stdout.includes('1 passing'), 'process stdout')
   })
 
   it('supports esm config files', async () => {
@@ -128,6 +129,7 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
+    ok(proc.stdout.includes('1 passing'), 'process stdout')
   })
 
   it('supports esm config files that return promises', async () => {
@@ -140,6 +142,7 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
+    ok(proc.stdout.includes('1 passing'), 'process stdout')
   })
 
   it('supports esm config files that return functions', async () => {
@@ -152,6 +155,7 @@ describe('mocha', function () {
     ])
 
     is(proc.exitCode, 0, 'exit code')
+    ok(proc.stdout.includes('1 passing'), 'process stdout')
   })
 })