Newrelic 3123/esm test loader

.gitignore

@@ -29,5 +29,8 @@ node_modules
 # VS Code settings
 .vscode
 
+# JetBrains settings
+.idea
+
 # Instanbul code coverage files
 .nyc_output

lib/versioned/runner.js

@@ -7,6 +7,7 @@
 'use strict'
 /* eslint-disable no-console */
 
+const path = require('path')
 const a = require('async')
 const cp = require('child_process')
 
@@ -97,7 +98,13 @@ function installPackages(cb) {
 function runTests(cb) {
   // TODO: Add tap arguments, such as color.
   process.send({ status: 'running' })
-  spawn('node', [testFile], function testHandler(err) {
+  let args = [testFile]
+  if (process.env.PKG_TYPE === 'module') {
+    const loaderPath = path.resolve(process.env.NR_LOADER)
+    args = ['--loader', loaderPath, testFile]
+  }
+
+  spawn('node', args, function testHandler(err) {
     if (err) {
       const error = new Error('Failed to execute test: ' + err.stack)
       error.code = Math.abs(err.code)

lib/versioned/test.js

@@ -80,6 +80,7 @@ function Test(directory, pkgVersions, opts = {}) {
   this.duration = 0
   this.allPkgs = !!allPkgs
   this.strict = !!opts.strict
+  this.type = pkg.type || 'commonjs'
 }
 
 Test.prototype.next = function next() {
@@ -102,7 +103,6 @@ Test.prototype.peek = function peek() {
 
 Test.prototype.run = function run() {
   const task = this.next()
-
   if (!task) {
     return null
   }
@@ -126,10 +126,29 @@ Test.prototype.run = function run() {
   // the one packages you were installing. The runner has a new -a prop that is a boolean
   const pkgList = this.allPkgs ? task.packageVersions : pkgs
 
+  const additionalArgs = {
+    PKG_TYPE: this.type
+  }
+
+  if (this.type === 'module') {
+    // The test loader is defined in the agent, so this uses process.cwd() instead of __directory.
+    const cwd = process.cwd()
+    let loaderPath = path.resolve(`${cwd}/test/lib/`, 'test-loader.mjs')
+    if (process.env.NR_LOADER) {
+      // Allow for override from environment
+      // This assumes that the loader path is defined in relation to the agent root.
+      loaderPath = path.resolve(cwd, process.env.NR_LOADER)
+    }
+    // changing env var for loader so subsequent commonjs
+    // runs that have NR_LOADER do not try to load it
+    additionalArgs.NR_LOADER = loaderPath
+  }
+
   // Spawn another runner instance with list of packages to install
   const child = cp.spawn('node', [TEST_EXECUTOR, task.test].concat(pkgList), {
     cwd: this.directory,
-    stdio: ['ignore', 'pipe', 'pipe', 'ipc']
+    stdio: ['ignore', 'pipe', 'pipe', 'ipc'],
+    env: { ...process.env, ...additionalArgs }
   })
 
   const testRun = new TestRun(child, pkgs.length > 0)

tests/unit/versioned/mock-esm-tests/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "mock-tests",
+  "version": "1.0.0",
+  "type": "module",
+  "private": true,
+  "tests": [{
+    "dependencies": {"redis": ">=1.0.0"},
+    "files": ["redis.mock.tap.js"]
+  }]
+}

tests/unit/versioned/mock-esm-tests/redis.mock.tap.js

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2020 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+console.log('stdout - redis.mock.tap.js')
+console.error('stderr - redis.mock.tap.js')
+/* eslint-disable no-process-exit */
+process.exit(0)

tests/unit/versioned/test.tap.js

@@ -8,6 +8,7 @@
 const path = require('path')
 const tap = require('tap')
 const fs = require('fs')
+const sinon = require('sinon')
 
 const Test = require('../../../lib/versioned/test')
 
@@ -17,16 +18,81 @@ const pkgVersions = {
   redis: { versions: ['1.0.0', '2.0.1', '2.1.0'], latest: '2.1.0' }
 }
 
+const ESM_MOCK_DIR = path.resolve(__dirname, 'mock-esm-tests')
+
 tap.test('Test construction', function (t) {
   let test = null
   t.doesNotThrow(function () {
     test = new Test(MOCK_TEST_DIR, pkgVersions)
   }, 'should not throw when constructed')
 
   t.type(test, Test, 'should construct a Test instance')
+  t.equal(test.type, 'commonjs', 'should default type to commonjs')
   t.end()
 })
 
+tap.test('ESM Tests', (t) => {
+  t.autoend()
+  const cp = require('child_process')
+  const esmVersions = {
+    redis: { versions: ['1.0.0'] }
+  }
+
+  t.before(() => {
+    sinon.spy(cp, 'spawn')
+  })
+
+  t.afterEach(() => {
+    cp.spawn.resetHistory()
+  })
+
+  t.teardown(() => {
+    cp.spawn.restore()
+  })
+
+  t.test('should properly construct test with type of module', (t) => {
+    let test = null
+    t.doesNotThrow(function () {
+      test = new Test(ESM_MOCK_DIR, esmVersions)
+    }, 'should not throw when constructed')
+
+    t.type(test, Test, 'should construct a Test instance')
+    t.equal(test.type, 'module', 'should default type to module')
+    t.end()
+  })
+
+  t.test('should default loader to test-loader.mjs when NR_LOADER is not specified', (t) => {
+    const test = new Test(ESM_MOCK_DIR, esmVersions)
+    const testRun = test.run()
+    const { env } = cp.spawn.args[0][2]
+    t.equal(env.NR_LOADER, `${process.cwd()}/test/lib/test-loader.mjs`, 'should use default loader')
+    // must force the mocked test run to complete so tap can shut down
+    testRun.continue()
+    testRun.once('completed', function () {
+      testRun.continue()
+      t.end()
+    })
+  })
+
+  t.test('should use NR_LOADER when specified', (t) => {
+    const test = new Test(ESM_MOCK_DIR, esmVersions)
+    process.env.NR_LOADER = 'bogus-loader.mjs'
+    const testRun = test.run()
+    const { env } = cp.spawn.args[0][2]
+    t.equal(
+      env.NR_LOADER,
+      `${process.cwd()}/bogus-loader.mjs`,
+      'should use NR_LOADER but resolves path'
+    )
+    // must force the mocked test run to complete so tap can shut down
+    testRun.continue()
+    testRun.once('completed', function () {
+      testRun.continue()
+      t.end()
+    })
+  })
+})
+
 tap.test('Test methods and members', function (t) {
   t.autoend()