feat: use IPC for granular test reporting (#43)

Resolves #26

README.md

@@ -55,6 +55,18 @@ module.exports = {
     'FOO_BAR': 'baz',
   },
 
+  // optional, whether or not to filter console output
+  // if unspecified, defaults to false
+  // if true, filters all output to stdout and stderr, except for the download
+  // of the VS Code executable, to only show the output of console.log(),
+  // console.error(), console.warn(), and console.info() calls made by tests.
+  //
+  // NOTE: This will not display output if you require() or import the console
+  // API in your tests, as only the global console object is overridden. It also
+  // will not work if you are using lower-level APIs such as
+  // process.stdout.write().
+  filterOutput: true,
+
   // optional, additional arguments to pass to VS Code
   launchArgs: [
     '--new-window',

e2e/__tests__/__snapshots__/passing-tests.ts.snap

@@ -5,13 +5,13 @@ Object {
   "numFailedTestSuites": 0,
   "numFailedTests": 0,
   "numPassedTestSuites": 1,
-  "numPassedTests": 2,
+  "numPassedTests": 3,
   "numPendingTestSuites": 0,
   "numPendingTests": 0,
   "numRuntimeErrorTestSuites": 0,
   "numTodoTests": 0,
   "numTotalTestSuites": 1,
-  "numTotalTests": 2,
+  "numTotalTests": 3,
   "openHandles": Array [],
   "snapshot": Object {
     "added": 0,
@@ -54,6 +54,16 @@ Object {
           "status": "passed",
           "title": "should test async",
         },
+        Object {
+          "ancestorTitles": Array [
+            "Describe",
+          ],
+          "failureMessages": Array [],
+          "fullName": "Describe should test with console.log",
+          "location": null,
+          "status": "passed",
+          "title": "should test with console.log",
+        },
       ],
       "endTime": undefined,
       "failureMessage": "",

e2e/__tests__/passing-tests.ts

@@ -15,6 +15,7 @@ describe('Passing tests', () => {
       console.error('stdout', stdout)
     }
     expect(json).toMatchSnapshot()
+    expect(stdout).toContain('This message was logged from the test file')
     expect(exitCode).toBe(0)
   }, 30000)
 })

e2e/jest-runner-vscode.config.js

@@ -1,7 +1,8 @@
-/** @type {import('../src/types').JestVSCodeRunnerOptions} */
+/** @type {import('../src/types').RunnerOptions} */
 const config = {
   version: '1.56.2',
   launchArgs: ['--disable-extensions'],
+  filterOutput: true,
 }
 
 module.exports = config

e2e/passing-tests/__tests__/test.js

@@ -6,4 +6,9 @@ describe('Describe', () => {
   it('should test async', async () => {
     expect(true).toBe(true)
   })
+
+  it('should test with console.log', () => {
+    console.log('This message was logged from the test file')
+    expect(true).toBe(true)
+  })
 })

src/child-process-runner.ts

@@ -1,10 +1,10 @@
-import type { RemoteTestOptions, RemoteTestResults } from './types'
+import type { RemoteTestOptions } from './types'
 import * as jest from '@jest/core'
 import type { buildArgv as buildArgvType } from 'jest-cli/build/cli/index'
 import vscode from 'vscode'
 import path from 'path'
 import process from 'process'
-import { IPC } from 'node-ipc'
+import IPCClient from './ipc-client'
 
 // eslint-disable-next-line @typescript-eslint/no-var-requires
 const buildArgv: typeof buildArgvType = require(path.resolve(
@@ -17,29 +17,15 @@ const vscodeModulePath = require.resolve('./jest-vscode-module')
 const moduleNameMapper = JSON.stringify({ '^vscode$': vscodeModulePath })
 
 export async function run(): Promise<void> {
-  const { IPC_CHANNEL, PARENT_JEST_OPTIONS } = process.env
-
-  if (!IPC_CHANNEL) {
-    throw new Error('IPC_CHANNEL is not defined')
-  }
-
-  const ipc = new IPC()
-
-  ipc.config.silent = true
-  ipc.config.id = `jest-runner-vscode-client-${process.pid}`
-
-  await new Promise<void>(resolve =>
-    ipc.connectTo(IPC_CHANNEL, () => {
-      ipc.of[IPC_CHANNEL].on('connect', resolve)
-    })
-  )
+  const ipc = new IPCClient('child')
 
   const disconnected = new Promise<void>(resolve =>
-    ipc.of[IPC_CHANNEL].on('disconnect', resolve)
+    ipc.on('disconnect', resolve)
   )
 
-  let response: RemoteTestResults
   try {
+    const { PARENT_JEST_OPTIONS } = process.env
+
     if (!PARENT_JEST_OPTIONS) {
       throw new Error('PARENT_JEST_OPTIONS is not defined')
     }
@@ -51,30 +37,20 @@ export async function run(): Promise<void> {
       '--runner=jest-runner',
       `--env=${vscodeTestEnvPath}`,
       `--moduleNameMapper=${moduleNameMapper}`,
+      `--reporters=${require.resolve('./child-reporter')}`,
       ...(options.globalConfig.updateSnapshot === 'all' ? ['-u'] : []),
       '--runTestsByPath',
       ...options.testPaths,
     ])
 
-    const { results } =
-      (await jest.runCLI(jestOptions, [options.globalConfig.rootDir])) ?? {}
-
-    response = {
-      is: 'ok',
-      results,
-    }
+    await jest.runCLI(jestOptions, [options.globalConfig.rootDir])
   } catch (error: any) {
     const errorObj = JSON.parse(
       JSON.stringify(error, Object.getOwnPropertyNames(error))
     )
-    response = {
-      is: 'error',
-      error: errorObj,
-    }
+    ipc.emit('error', errorObj)
   }
 
-  ipc.of[IPC_CHANNEL].emit('test-results', response)
-  ipc.disconnect(IPC_CHANNEL)
-  await disconnected
+  await Promise.race([disconnected, ipc.disconnect()])
   await vscode.commands.executeCommand('workbench.action.closeWindow')
 }

src/child-reporter.ts

@@ -0,0 +1,88 @@
+import type {
+  AggregatedResult,
+  TestCaseResult,
+  TestResult,
+} from '@jest/test-result'
+import type {
+  ReporterOnStartOptions,
+  Test,
+  Reporter,
+  Context,
+} from '@jest/reporters'
+import IPCClient from './ipc-client'
+import wrapIO from './wrap-io'
+
+export default class ChildReporter implements Reporter {
+  #ipc: IPCClient
+  #onConnected: Promise<void>
+
+  constructor() {
+    this.#ipc = new IPCClient('reporter')
+    this.#onConnected = this.#ipc.connect()
+
+    wrapIO(this.#ipc)
+  }
+
+  getLastError() {
+    return undefined
+  }
+
+  onTestResult(
+    test: Test,
+    testResult: TestResult,
+    aggregatedResult: AggregatedResult
+  ): void {
+    this.#ipc.emit('testResult', {
+      test,
+      testResult,
+      aggregatedResult,
+    })
+  }
+
+  onTestFileResult(
+    test: Test,
+    testResult: TestResult,
+    aggregatedResult: AggregatedResult
+  ): void {
+    this.#ipc.emit('testFileResult', {
+      test,
+      testResult,
+      aggregatedResult,
+    })
+  }
+
+  onTestCaseResult(test: Test, testCaseResult: TestCaseResult): void {
+    this.#ipc.emit('testCaseResult', {
+      test,
+      testCaseResult,
+    })
+  }
+
+  onRunStart(
+    aggregatedResult: AggregatedResult,
+    options: ReporterOnStartOptions
+  ): void {
+    this.#ipc.emit('runStart', {
+      aggregatedResult,
+      options,
+    })
+  }
+
+  onTestStart(test: Test): void {
+    this.#ipc.emit('testStart', { test })
+  }
+
+  onTestFileStart(test: Test): void {
+    this.#ipc.emit('testFileStart', { test })
+  }
+
+  async onRunComplete(
+    contexts: Set<Context>,
+    results: AggregatedResult
+  ): Promise<void> {
+    this.#ipc.emit('runComplete', { contexts, results })
+
+    await this.#onConnected
+    await this.#ipc.disconnect()
+  }
+}

src/ipc-client.ts

@@ -0,0 +1,117 @@
+import console from 'console'
+import EventEmitter from 'events'
+import { IPC } from 'node-ipc'
+import MessageWriter from './message-writer'
+
+export default class IPCClient {
+  #ipc: InstanceType<typeof IPC>
+  #ipcChannel: string
+  #messageQueue: Array<[string, unknown]> = []
+  #writer: MessageWriter
+  #connected = false
+  #promises: Set<Promise<void>> = new Set()
+  #emitter: EventEmitter = new EventEmitter()
+
+  get on(): EventEmitter['on'] {
+    return this.#emitter.on.bind(this.#emitter)
+  }
+
+  get once(): EventEmitter['once'] {
+    return this.#emitter.once.bind(this.#emitter)
+  }
+
+  get off(): EventEmitter['off'] {
+    return this.#emitter.off.bind(this.#emitter)
+  }
+
+  get removeListener(): EventEmitter['removeListener'] {
+    return this.#emitter.removeListener.bind(this.#emitter)
+  }
+
+  get removeAllListeners(): EventEmitter['removeAllListeners'] {
+    return this.#emitter.removeAllListeners.bind(this.#emitter)
+  }
+
+  constructor(id: string) {
+    const { IPC_CHANNEL, DEBUG_VSCODE_IPC } = process.env
+
+    if (!IPC_CHANNEL) {
+      throw new Error('IPC_CHANNEL is not defined')
+    }
+
+    this.#ipcChannel = IPC_CHANNEL
+
+    this.#ipc = new IPC()
+    this.#ipc.config.silent = !DEBUG_VSCODE_IPC
+    this.#ipc.config.id = `jest-runner-vscode-${id}-${process.pid}`
+    this.#ipc.config.logger = (message: string) => {
+      // keep message no longer than 500 characters
+      const truncatedMessage =
+        message.length > 500 ? `${message.slice(0, 500)}...\u001b[0m` : message
+
+      console.log(truncatedMessage)
+    }
+
+    this.#writer = new MessageWriter(this.#ipc, this.#ipcChannel)
+  }
+
+  async #flush(): Promise<void> {
+    while (this.#messageQueue.length) {
+      const message = this.#messageQueue.shift()
+
+      if (message) {
+        const [type, data] = message
+
+        await this.#writer.write(type, data)
+
+        this.#emitter.emit(type, data)
+      }
+    }
+  }
+
+  async connect(): Promise<void> {
+    return new Promise<void>(resolve => {
+      this.#ipc.connectTo(this.#ipcChannel, async () => {
+        this.#connected = true
+
+        await this.#flush()
+
+        this.#emitter.emit('connect')
+
+        this.#ipc.of[this.#ipcChannel].on('disconnect', () => {
+          this.#connected = false
+          this.#emitter.emit('disconnect')
+        })
+
+        resolve()
+      })
+    })
+  }
+
+  async disconnect(): Promise<void> {
+    if (!this.#connected) {
+      return
+    }
+
+    await Promise.all(this.#promises)
+
+    const disconnected = new Promise<void>(resolve => {
+      this.#emitter.once('disconnect', resolve)
+    })
+
+    this.#ipc.disconnect(this.#ipcChannel)
+
+    return disconnected
+  }
+
+  emit(type: string, data: unknown): void {
+    if (!this.#connected) {
+      this.#messageQueue.push([type, data])
+    } else {
+      const promise = this.#writer.write(type, data)
+
+      this.#promises.add(promise)
+      promise.then(() => this.#promises.delete(promise))
+    }
+  }
+}

src/jest-vscode-env.ts

@@ -1,14 +1,21 @@
 import NodeEnvironment from 'jest-environment-node'
 import vscode from 'vscode'
+import IPCClient from './ipc-client'
+import wrapIO from './wrap-io'
+
+const ipc = new IPCClient('env')
 
 class VSCodeEnvironment extends NodeEnvironment {
   async setup() {
     await super.setup()
     this.global.vscode = vscode
+    await ipc.connect()
+    await wrapIO(ipc, this.global)
   }
 
   async teardown() {
     this.global.vscode = {}
+    await ipc.disconnect()
     await super.teardown()
   }
 }

src/js-message.d.ts

@@ -0,0 +1,6 @@
+declare module 'js-message' {
+  export default class Message {
+    type: string
+    data: unknown
+  }
+}