feat: add config option logHeapUsage

docs/config/index.md

@@ -448,3 +448,10 @@ export default {
   },
 }
 ```
+
+### logHeapUsage
+
+- **Type**: `boolean`
+- **Default**: `false`
+
+Show heap usage after each test. Usefull for debugging memory leaks.

packages/vitest/src/node/reporters/base.ts

@@ -16,6 +16,8 @@ const HELP_QUITE = `${c.dim('press ')}${c.bold('q')}${c.dim(' to quit')}`
 const WAIT_FOR_CHANGE_PASS = `\n${c.bold(c.inverse(c.green(' PASS ')))}${c.green(' Waiting for file changes...')}`
 const WAIT_FOR_CHANGE_FAIL = `\n${c.bold(c.inverse(c.red(' FAIL ')))}${c.red(' Tests failed. Watching for file changes...')}`
 
+const DURATION_LONG = 300
+
 export abstract class BaseReporter implements Reporter {
   start = 0
   end = 0
@@ -86,8 +88,12 @@ export abstract class BaseReporter implements Reporter {
         if (skipped.length)
           state += ` ${c.dim('|')} ${c.yellow(`${skipped.length} skipped`)}`
         let suffix = c.dim(' (') + state + c.dim(')')
-        if (task.result.duration)
-          suffix += c.yellow(` ${Math.round(task.result.duration)}${c.dim('ms')}`)
+        if (task.result.duration) {
+          const color = task.result.duration > DURATION_LONG ? c.yellow : c.gray
+          suffix += color(` ${Math.round(task.result.duration)}${c.dim('ms')}`)
+        }
+        if (this.ctx.config.logHeapUsage && task.result.heap != null)
+          suffix += c.magenta(` ${Math.floor(task.result.heap / 1024 / 1024)} MB heap used`)
 
         this.ctx.log(` ${getStateSymbol(task)} ${task.name} ${suffix}`)
 

packages/vitest/src/node/reporters/default.ts

@@ -22,6 +22,7 @@ export class DefaultReporter extends BaseReporter {
   onCollected() {
     if (this.isTTY) {
       this.rendererOptions.outputStream = this.ctx.outputStream
+      this.rendererOptions.showHeap = this.ctx.config.logHeapUsage
       const files = this.ctx.state.getFiles(this.watchFilters)
       if (!this.renderer)
         this.renderer = createListRenderer(files, this.rendererOptions).start()

packages/vitest/src/node/reporters/renderers/listRenderer.ts

@@ -10,6 +10,7 @@ import { getCols, getHookStateSymbol, getStateSymbol } from './utils'
 export interface ListRendererOptions {
   renderSucceed?: boolean
   outputStream: NodeJS.WritableStream
+  showHeap: boolean
 }
 
 const DURATION_LONG = 300
@@ -53,6 +54,9 @@ export function renderTree(tasks: Task[], options: ListRendererOptions, level =
         suffix += c.yellow(` ${Math.round(task.result.duration)}${c.dim('ms')}`)
     }
 
+    if (options.showHeap && task.result?.heap != null)
+      suffix += c.magenta(` ${Math.floor(task.result.heap / 1024 / 1024)} MB heap used`)
+
     let name = task.name
     if (level === 0)
       name = formatFilepath(name)

packages/vitest/src/node/reporters/verbose.ts

@@ -17,7 +17,10 @@ export class VerboseReporter extends DefaultReporter {
     for (const pack of packs) {
       const task = this.ctx.state.idMap.get(pack[0])
       if (task && task.type === 'test' && task.result?.state && task.result?.state !== 'run') {
-        this.ctx.log(` ${getStateSymbol(task)} ${getFullName(task)}`)
+        let title = ` ${getStateSymbol(task)} ${getFullName(task)}`
+        if (this.ctx.config.logHeapUsage && task.result.heap != null)
+          title += c.magenta(` ${Math.floor(task.result.heap / 1024 / 1024)} MB heap used`)
+        this.ctx.log(title)
         if (task.result.state === 'fail')
           this.ctx.log(c.red(`   ${F_RIGHT} ${(task.result.error as any)?.message}`))
       }

packages/vitest/src/runtime/run.ts

@@ -51,9 +51,9 @@ export async function callSuiteHook<T extends keyof SuiteHooks>(
   return callbacks
 }
 
-const packs = new Map<string, TaskResult|undefined>()
+const packs = new Map<string, TaskResult | undefined>()
 let updateTimer: any
-let previousUpdate: Promise<void>|undefined
+let previousUpdate: Promise<void> | undefined
 
 function updateTask(task: Task) {
   packs.set(task.id, task.result)
@@ -151,6 +151,9 @@ export async function runTest(test: Test) {
 
   test.result.duration = now() - start
 
+  if (workerState.config.logHeapUsage)
+    test.result.heap = process.memoryUsage().heapUsed
+
   workerState.current = undefined
 
   updateTask(test)
@@ -212,6 +215,11 @@ export async function runSuite(suite: Suite) {
   }
   suite.result.duration = now() - start
 
+  const workerState = getWorkerState()
+
+  if (workerState.config.logHeapUsage)
+    suite.result.heap = process.memoryUsage().heapUsed
+
   if (suite.mode === 'run') {
     if (!hasTests(suite)) {
       suite.result.state = 'fail'

packages/vitest/src/types/config.ts

@@ -297,6 +297,11 @@ export interface InlineConfig {
    * Resolve custom snapshot path
    */
   resolveSnapshotPath?: (path: string, extension: string) => string
+
+  /**
+   * Show heap usage after each test. Usefull for debugging memory leaks.
+   */
+  logHeapUsage?: boolean
 }
 
 export interface UserConfig extends InlineConfig {

packages/vitest/src/types/tasks.ts

@@ -20,6 +20,7 @@ export interface TaskResult {
   state: TaskState
   duration?: number
   startTime?: number
+  heap?: number
   error?: ErrorWithDiff
   htmlError?: string
   hooks?: Partial<Record<keyof SuiteHooks, TaskState>>