fix: save and restore module graph in blob reporter

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

@@ -1,5 +1,6 @@
 import type { File } from '@vitest/runner'
 import type { SerializedError } from '@vitest/utils'
+import type { DevEnvironment, EnvironmentModuleNode } from 'vite'
 import type { Vitest } from '../core'
 import type { TestProject } from '../project'
 import type { Reporter } from '../types/reporter'
@@ -54,27 +55,40 @@ export class BlobReporter implements Reporter {
         : '.vitest-reports/blob.json'
     }
 
-    const modules = this.ctx.projects.map<MergeReportModuleKeys>(
-      (project) => {
-        return [
-          project.name,
-          [...project.vite.moduleGraph.idToModuleMap.entries()].map<SerializedModuleNode | null>((mod) => {
-            if (!mod[1].file) {
-              return null
-            }
-            return [mod[0], mod[1].file, mod[1].url]
-          }).filter(x => x != null),
-        ]
-      },
-    )
+    const environmentModules: MergeReportEnvironmentModules = {}
+    this.ctx.projects.forEach((project) => {
+      const serializedProject: MergeReportEnvironmentModules[string] = {
+        environments: {},
+        external: [],
+      }
+      Object.entries(project.vite.environments).forEach(([environmentName, environment]) => {
+        serializedProject.environments[environmentName] = serializeEnvironmentModuleGraph(
+          environment,
+        )
+      })
+
+      if (project.browser?.vite.environments.client) {
+        serializedProject.browser = serializeEnvironmentModuleGraph(
+          project.browser.vite.environments.client,
+        )
+      }
+
+      for (const [id, value] of project._resolver.externalizeCache.entries()) {
+        if (typeof value === 'string') {
+          serializedProject.external.push([id, value])
+        }
+      }
+
+      environmentModules[project.name] = serializedProject
+    })
 
     const report = [
       this.ctx.version,
       files,
       errors,
-      modules,
       coverage,
       executionTime,
+      environmentModules,
     ] satisfies MergeReport
 
     const reportFile = resolve(this.ctx.config.root, outputFile)
@@ -112,15 +126,15 @@ export async function readBlobs(
       )
     }
     const content = await readFile(fullPath, 'utf-8')
-    const [version, files, errors, moduleKeys, coverage, executionTime] = parse(
+    const [version, files, errors, coverage, executionTime, environmentModules] = parse(
       content,
     ) as MergeReport
     if (!version) {
       throw new TypeError(
         `vitest.mergeReports() expects all paths in "${blobsDirectory}" to be files generated by the blob reporter, but "${filename}" is not a valid blob file`,
       )
     }
-    return { version, files, errors, moduleKeys, coverage, file: filename, executionTime }
+    return { version, files, errors, coverage, file: filename, executionTime, environmentModules }
   })
   const blobs = await Promise.all(promises)
 
@@ -143,28 +157,38 @@ export async function readBlobs(
     )
   }
 
-  // fake module graph - it is used to check if module is imported, but we don't use values inside
+  // Restore module graph
   const projects = Object.fromEntries(
     projectsArray.map(p => [p.name, p]),
   )
 
+  for (const project of projectsArray) {
+    if (project.isBrowserEnabled()) {
+      await project._initBrowserServer()
+    }
+  }
+
   blobs.forEach((blob) => {
-    blob.moduleKeys.forEach(([projectName, moduleIds]) => {
+    Object.entries(blob.environmentModules).forEach(([projectName, modulesByProject]) => {
       const project = projects[projectName]
       if (!project) {
         return
       }
-      moduleIds.forEach(([moduleId, file, url]) => {
-        const moduleNode = project.vite.moduleGraph.createFileOnlyEntry(file)
-        moduleNode.url = url
-        moduleNode.id = moduleId
-        moduleNode.transformResult = {
-          // print error checks that transformResult is set
-          code: ' ',
-          map: null,
-        }
-        project.vite.moduleGraph.idToModuleMap.set(moduleId, moduleNode)
+
+      modulesByProject.external.forEach(([id, externalized]) => {
+        project._resolver.externalizeCache.set(id, externalized)
       })
+
+      Object.entries(modulesByProject.environments).forEach(([environmentName, moduleGraph]) => {
+        const environment = project.vite.environments[environmentName]
+        deserializeEnvironmentModuleGraph(environment, moduleGraph)
+      })
+
+      const browserModuleGraph = modulesByProject.browser
+      if (browserModuleGraph) {
+        const browserEnvironment = project.browser!.vite.environments.client
+        deserializeEnvironmentModuleGraph(browserEnvironment, browserModuleGraph)
+      }
     })
   })
 
@@ -198,18 +222,107 @@ type MergeReport = [
   vitestVersion: string,
   files: File[],
   errors: unknown[],
-  modules: MergeReportModuleKeys[],
   coverage: unknown,
   executionTime: number,
+  environmentModules: MergeReportEnvironmentModules,
 ]
 
-type SerializedModuleNode = [
-  id: string,
-  file: string,
-  url: string,
-]
+interface MergeReportEnvironmentModules {
+  [projectName: string]: {
+    environments: {
+      [environmentName: string]: SerializedEnvironmentModuleGraph
+    }
+    browser?: SerializedEnvironmentModuleGraph
+    external: [id: string, externalized: string][]
+  }
+}
 
-type MergeReportModuleKeys = [
-  projectName: string,
-  modules: SerializedModuleNode[],
+type SerializedEnvironmentModuleNode = [
+  id: number,
+  file: number,
+  url: number,
+  importedIds: number[],
 ]
+
+interface SerializedEnvironmentModuleGraph {
+  idTable: string[]
+  modules: SerializedEnvironmentModuleNode[]
+}
+
+function serializeEnvironmentModuleGraph(
+  environment: DevEnvironment,
+): SerializedEnvironmentModuleGraph {
+  const idTable: string[] = []
+  const idMap = new Map<string, number>()
+
+  const getIdIndex = (id: string) => {
+    const existing = idMap.get(id)
+    if (existing != null) {
+      return existing
+    }
+    const next = idTable.length
+    idMap.set(id, next)
+    idTable.push(id)
+    return next
+  }
+
+  const modules: SerializedEnvironmentModuleNode[] = []
+  for (const [id, mod] of environment.moduleGraph.idToModuleMap.entries()) {
+    if (!mod.file) {
+      continue
+    }
+
+    const importedIds: number[] = []
+    for (const importedNode of mod.importedModules) {
+      if (importedNode.id) {
+        importedIds.push(getIdIndex(importedNode.id))
+      }
+    }
+
+    modules.push([
+      getIdIndex(id),
+      getIdIndex(mod.file),
+      getIdIndex(mod.url),
+      importedIds,
+    ])
+  }
+
+  return {
+    idTable,
+    modules,
+  }
+}
+
+function deserializeEnvironmentModuleGraph(
+  environment: DevEnvironment,
+  serialized: SerializedEnvironmentModuleGraph,
+): void {
+  const nodesById = new Map<string, EnvironmentModuleNode>()
+
+  serialized.modules.forEach(([id, file, url]) => {
+    const moduleId = serialized.idTable[id]
+    const filePath = serialized.idTable[file]
+    const urlPath = serialized.idTable[url]
+    const moduleNode = environment.moduleGraph.createFileOnlyEntry(filePath)
+    moduleNode.url = urlPath
+    moduleNode.id = moduleId
+    moduleNode.transformResult = {
+      // print error checks that transformResult is set
+      code: ' ',
+      map: null,
+    }
+    environment.moduleGraph.idToModuleMap.set(moduleId, moduleNode)
+    nodesById.set(moduleId, moduleNode)
+  })
+
+  serialized.modules.forEach(([id, _file, _url, importedIds]) => {
+    const moduleId = serialized.idTable[id]
+    const moduleNode = nodesById.get(moduleId)!
+    importedIds.forEach((importedIdIndex) => {
+      const importedId = serialized.idTable[importedIdIndex]
+      const importedNode = nodesById.get(importedId)!
+      moduleNode.importedModules.add(importedNode)
+      importedNode.importers.add(moduleNode)
+    })
+  })
+}

packages/vitest/src/node/resolver.ts

@@ -12,7 +12,7 @@ import { isWindows } from '../utils/env'
 export class VitestResolver {
   public readonly options: ExternalizeOptions
   private externalizeConcurrentCache = new Map<string, Promise<string | false | undefined>>()
-  private externalizeCache = new Map<string, string | false | undefined>()
+  public externalizeCache: Map<string, string | false | undefined> = new Map()
 
   constructor(cacheDir: string, config: ResolvedConfig) {
     // sorting to make cache consistent

test/cli/fixtures/reporters/merge-reports-module-graph/basic.test.ts

@@ -0,0 +1,8 @@
+import { test, expect } from 'vitest'
+import { formatHello } from './sub/format'
+import { hello } from './util'
+
+test('passes', () => {
+  expect(hello()).toBe('Hello, graph!')
+  expect(formatHello()).toBe('Hello, graph!')
+})

test/cli/fixtures/reporters/merge-reports-module-graph/second.test.ts

@@ -0,0 +1,11 @@
+import { test, expect } from 'vitest'
+import { hello } from './util'
+import * as obug from "obug"
+
+test('also passes', () => {
+  expect(hello()).toBe('Hello, graph!')
+})
+
+test('external', () => {
+  expect(obug).toBeTypeOf('object')
+})

test/cli/fixtures/reporters/merge-reports-module-graph/sub/format.ts

@@ -0,0 +1,5 @@
+import { getSubject } from './subject'
+
+export function formatHello() {
+  return `Hello, ${getSubject()}!`
+}

test/cli/fixtures/reporters/merge-reports-module-graph/sub/subject.ts

@@ -0,0 +1,3 @@
+export function getSubject() {
+  return 'graph'
+}

test/cli/fixtures/reporters/merge-reports-module-graph/util.ts

@@ -0,0 +1,5 @@
+import { getSubject } from './sub/subject'
+
+export function hello() {
+  return `Hello, ${getSubject()}!`
+}

test/cli/fixtures/reporters/merge-reports-module-graph/vitest.config.js

@@ -0,0 +1,3 @@
+import { defineConfig } from "vitest/config"
+
+export default defineConfig({})