fix(coverage): don't crash when re-run removes earlier run's reports

packages/coverage-istanbul/src/provider.ts

@@ -53,6 +53,10 @@ export class IstanbulCoverageProvider extends BaseCoverageProvider implements Co
   coverageFilesDirectory!: string
   pendingPromises: Promise<void>[] = []
 
+  onRunFinish: (() => void) | null = null
+  runningPromise: Promise<void> | null = null
+  cancelRun = false
+
   initialize(ctx: Vitest) {
     const config: CoverageIstanbulOptions = ctx.config.coverage
 
@@ -145,6 +149,20 @@ export class IstanbulCoverageProvider extends BaseCoverageProvider implements Co
   }
 
   async clean(clean = true) {
+    if (this.runningPromise) {
+      this.cancelRun = true
+      await this.runningPromise
+    }
+
+    this.runningPromise = new Promise<void>((resolve) => {
+      this.onRunFinish = () => {
+        resolve()
+        this.onRunFinish = null
+        this.runningPromise = null
+        this.cancelRun = false
+      }
+    })
+
     if (clean && existsSync(this.options.reportsDirectory))
       await fs.rm(this.options.reportsDirectory, { recursive: true, force: true, maxRetries: 10 })
 
@@ -176,11 +194,17 @@ export class IstanbulCoverageProvider extends BaseCoverageProvider implements Co
           }
 
           await Promise.all(chunk.map(async (filename) => {
+            if (this.cancelRun)
+              return
+
             const contents = await fs.readFile(filename, 'utf-8')
             const coverage = JSON.parse(contents) as CoverageMap
 
             coverageMapByTransformMode.merge(coverage)
           }))
+
+          if (this.cancelRun)
+            return this.onRunFinish?.()
         }
 
         // Source maps can change based on projectName and transform mode.
@@ -247,6 +271,7 @@ export class IstanbulCoverageProvider extends BaseCoverageProvider implements Co
 
     await fs.rm(this.coverageFilesDirectory, { recursive: true })
     this.coverageFiles = new Map()
+    this.onRunFinish?.()
   }
 
   async getCoverageMapForUncoveredFiles(coveredFiles: string[]) {

packages/coverage-v8/src/provider.ts

@@ -68,6 +68,10 @@ export class V8CoverageProvider extends BaseCoverageProvider implements Coverage
   coverageFilesDirectory!: string
   pendingPromises: Promise<void>[] = []
 
+  onRunFinish: (() => void) | null = null
+  runningPromise: Promise<void> | null = null
+  cancelRun = false
+
   initialize(ctx: Vitest) {
     const config: CoverageV8Options = ctx.config.coverage
 
@@ -109,6 +113,20 @@ export class V8CoverageProvider extends BaseCoverageProvider implements Coverage
   }
 
   async clean(clean = true) {
+    if (this.runningPromise) {
+      this.cancelRun = true
+      await this.runningPromise
+    }
+
+    this.runningPromise = new Promise<void>((resolve) => {
+      this.onRunFinish = () => {
+        resolve()
+        this.onRunFinish = null
+        this.runningPromise = null
+        this.cancelRun = false
+      }
+    })
+
     if (clean && existsSync(this.options.reportsDirectory))
       await fs.rm(this.options.reportsDirectory, { recursive: true, force: true, maxRetries: 10 })
 
@@ -166,10 +184,16 @@ export class V8CoverageProvider extends BaseCoverageProvider implements Coverage
           }
 
           await Promise.all(chunk.map(async (filename) => {
+            if (this.cancelRun)
+              return
+
             const contents = await fs.readFile(filename, 'utf-8')
             const coverage = JSON.parse(contents) as RawCoverage
             merged = mergeProcessCovs([merged, coverage])
           }))
+
+          if (this.cancelRun)
+            return this.onRunFinish?.()
         }
 
         const converted = await this.convertCoverage(merged, projectName, transformMode)
@@ -239,6 +263,7 @@ export class V8CoverageProvider extends BaseCoverageProvider implements Coverage
 
     this.coverageFiles = new Map()
     await fs.rm(this.coverageFilesDirectory, { recursive: true })
+    this.onRunFinish?.()
   }
 
   private async getUntestedFiles(testedFiles: string[]): Promise<RawCoverage> {

packages/vitest/src/node/core.ts

@@ -346,7 +346,6 @@ export class Vitest {
 
     try {
       await this.initCoverageProvider()
-      await this.coverageProvider?.clean(this.config.coverage.clean)
       await this.initBrowserProviders()
     }
     finally {
@@ -377,7 +376,7 @@ export class Vitest {
       // populate once, update cache on watch
       await this.cache.stats.populateStats(this.config.root, files)
 
-      await this.runFiles(files)
+      await this.runFiles(files, true)
     }
 
     await this.reportCoverage(true)
@@ -472,7 +471,7 @@ export class Vitest {
       await project.initializeGlobalSetup()
   }
 
-  async runFiles(paths: WorkspaceSpec[]) {
+  async runFiles(paths: WorkspaceSpec[], isFirstRun = false) {
     const filepaths = paths.map(([, file]) => file)
     this.state.collectPaths(filepaths)
 
@@ -492,6 +491,8 @@ export class Vitest {
       this.invalidates.clear()
       this.snapshot.clear()
       this.state.clearErrors()
+      await this.coverageProvider?.clean(isFirstRun ? this.config.coverage.clean : this.config.coverage.cleanOnRerun)
+
       await this.initializeGlobalSetup(paths)
 
       try {
@@ -530,9 +531,6 @@ export class Vitest {
       files = files.filter(file => filteredFiles.some(f => f[1] === file))
     }
 
-    if (this.coverageProvider && this.config.coverage.cleanOnRerun)
-      await this.coverageProvider.clean()
-
     await this.report('onWatcherRerun', files, trigger)
     await this.runFiles(files.flatMap(file => this.getProjectsByTestFile(file)))
 
@@ -632,9 +630,6 @@ export class Vitest {
 
       this.changedTests.clear()
 
-      if (this.coverageProvider && this.config.coverage.cleanOnRerun)
-        await this.coverageProvider.clean()
-
       const triggerIds = new Set(triggerId.map(id => relative(this.config.root, id)))
       const triggerLabel = Array.from(triggerIds).join(', ')
       await this.report('onWatcherRerun', files, triggerLabel)