chore: add filesCache

packages/vitest/src/node/cache/files.ts

@@ -0,0 +1,23 @@
+import fs, { type Stats } from 'fs'
+
+type FileCacheStats = Pick<Stats, 'size'>
+
+export class FilesCache {
+  public cache = new Map<string, FileCacheStats>()
+
+  public getStats(fsPath: string): FileCacheStats | undefined {
+    return this.cache.get(fsPath)
+  }
+
+  public async updateStats(fsPath: string) {
+    if (!fs.existsSync(fsPath))
+      return
+
+    const stats = await fs.promises.stat(fsPath)
+    this.cache.set(fsPath, { size: stats.size })
+  }
+
+  public removeStats(fsPath: string) {
+    this.cache.delete(fsPath)
+  }
+}

packages/vitest/src/node/core.ts

@@ -136,6 +136,9 @@ export class Vitest {
       process.exit(exitCode)
     }
 
+    // populate once, update cache on watch
+    await Promise.all(files.map(file => this.state.stats.updateStats(file)))
+
     await this.runFiles(files)
 
     if (this.config.coverage.enabled)
@@ -361,6 +364,7 @@ export class Vitest {
       if (this.state.filesMap.has(id)) {
         this.state.filesMap.delete(id)
         this.state.results.removeFromCache(id)
+        this.state.stats.removeStats(id)
         this.changedTests.delete(id)
         this.report('onTestRemoved', id)
       }
@@ -369,6 +373,7 @@ export class Vitest {
       id = slash(id)
       if (await this.isTargetFile(id)) {
         this.changedTests.add(id)
+        await this.state.stats.updateStats(id)
         this.scheduleRerun(id)
       }
     }

packages/vitest/src/node/pool.ts

@@ -114,8 +114,16 @@ export function createPool(ctx: Vitest): WorkerPool {
         const aState = ctx.state.results.getResults(a)
         const bState = ctx.state.results.getResults(b)
 
-        if (!aState || !bState)
-          return !aState && bState ? -1 : !bState && aState ? 1 : 0
+        if (!aState || !bState) {
+          const statsA = ctx.state.stats.getStats(a)
+          const statsB = ctx.state.stats.getStats(b)
+
+          if (!statsA || !statsB)
+            return !aState && bState ? -1 : !bState && aState ? 1 : 0
+
+          // run larger files first
+          return statsB.size - statsA.size
+        }
 
         // run failed first
         if (aState.failed && !bState.failed)

packages/vitest/src/node/state.ts

@@ -1,4 +1,5 @@
 import type { ErrorWithDiff, File, Task, TaskResultPack, UserConsoleLog } from '../types'
+import { FilesCache } from './cache/files'
 import { ResultsCache } from './cache/results'
 
 export class StateManager {
@@ -7,6 +8,7 @@ export class StateManager {
   taskFileMap = new WeakMap<Task, File>()
   errorsSet = new Set<unknown>()
   results = new ResultsCache()
+  stats = new FilesCache()
 
   catchError(err: unknown, type: string) {
     (err as ErrorWithDiff).type = type