feat: custom "snapshotEnvironment" option (#5449)

Author: sheremet-va

docs/config/index.md

@@ -2200,3 +2200,31 @@ The `location` property has `column` and `line` values that correspond to the `t
 ::: tip
 This option has no effect if you do not use custom code that relies on this.
 :::
+
+### snapshotEnvironment <Version>1.6.0</Version> {#snapshotEnvironment}
+
+- **Type:** `string`
+
+Path to a custom snapshot environment implementation. This is useful if you are running your tests in an environment that doesn't support Node.js APIs. This option doesn't have any effect on a browser runner.
+
+This object should have the shape of `SnapshotEnvironment` and is used to resolve and read/write snapshot files:
+
+```ts
+export interface SnapshotEnvironment {
+  getVersion: () => string
+  getHeader: () => string
+  resolvePath: (filepath: string) => Promise<string>
+  resolveRawPath: (testPath: string, rawPath: string) => Promise<string>
+  saveSnapshotFile: (filepath: string, snapshot: string) => Promise<void>
+  readSnapshotFile: (filepath: string) => Promise<string | null>
+  removeSnapshotFile: (filepath: string) => Promise<void>
+}
+```
+
+You can extend default `VitestSnapshotEnvironment` from `vitest/snapshot` entry point if you need to overwrite only a part of the API.
+
+::: warning
+This is a low-level option and should be used only for advanced cases where you don't have access to default Node.js APIs.
+
+If you just need to configure snapshots feature, use [`snapshotFormat`](#snapshotformat) or [`resolveSnapshotPath`](#resolvesnapshotpath) options.
+:::

packages/browser/src/client/runner.ts

@@ -3,7 +3,7 @@ import type { ResolvedConfig } from 'vitest'
 import type { VitestExecutor } from 'vitest/execute'
 import { rpc } from './rpc'
 import { getConfig, importId } from './utils'
-import { BrowserSnapshotEnvironment } from './snapshot'
+import { VitestBrowserSnapshotEnvironment } from './snapshot'
 
 interface BrowserRunnerOptions {
   config: ResolvedConfig
@@ -92,7 +92,10 @@ export async function initiateRunner() {
   if (cachedRunner)
     return cachedRunner
   const config = getConfig()
-  const [{ VitestTestRunner, NodeBenchmarkRunner }, { takeCoverageInsideWorker, loadDiffConfig, loadSnapshotSerializers }] = await Promise.all([
+  const [
+    { VitestTestRunner, NodeBenchmarkRunner },
+    { takeCoverageInsideWorker, loadDiffConfig, loadSnapshotSerializers },
+  ] = await Promise.all([
     importId('vitest/runners') as Promise<typeof import('vitest/runners')>,
     importId('vitest/browser') as Promise<typeof import('vitest/browser')>,
   ])
@@ -101,7 +104,7 @@ export async function initiateRunner() {
     takeCoverage: () => takeCoverageInsideWorker(config.coverage, { executeId: importId }),
   })
   if (!config.snapshotOptions.snapshotEnvironment)
-    config.snapshotOptions.snapshotEnvironment = new BrowserSnapshotEnvironment()
+    config.snapshotOptions.snapshotEnvironment = new VitestBrowserSnapshotEnvironment()
   const runner = new BrowserRunner({
     config,
   })

packages/browser/src/client/snapshot.ts

@@ -1,7 +1,7 @@
-import type { SnapshotEnvironment } from 'vitest'
-import { rpc } from './rpc'
+import type { VitestClient } from '@vitest/ws-client'
+import type { SnapshotEnvironment } from 'vitest/snapshot'
 
-export class BrowserSnapshotEnvironment implements SnapshotEnvironment {
+export class VitestBrowserSnapshotEnvironment implements SnapshotEnvironment {
   getVersion(): string {
     return '1'
   }
@@ -30,3 +30,8 @@ export class BrowserSnapshotEnvironment implements SnapshotEnvironment {
     return rpc().removeSnapshotFile(filepath)
   }
 }
+
+function rpc(): VitestClient['rpc'] {
+  // @ts-expect-error not typed global
+  return globalThis.__vitest_worker__.rpc
+}

packages/vitest/package.json

@@ -91,6 +91,10 @@
     "./reporters": {
       "types": "./dist/reporters.d.ts",
       "default": "./dist/reporters.js"
+    },
+    "./snapshot": {
+      "types": "./dist/snapshot.d.ts",
+      "default": "./dist/snapshot.js"
     }
   },
   "main": "./dist/index.js",

packages/vitest/rollup.config.js

@@ -41,6 +41,8 @@ const entries = {
   'workers/vmForks': 'src/runtime/workers/vmForks.ts',
 
   'workers/runVmTests': 'src/runtime/runVmTests.ts',
+
+  'snapshot': 'src/snapshot.ts',
 }
 
 const dtsEntries = {
@@ -56,6 +58,7 @@ const dtsEntries = {
   execute: 'src/public/execute.ts',
   reporters: 'src/public/reporters.ts',
   workers: 'src/workers.ts',
+  snapshot: 'src/snapshot.ts',
 }
 
 const external = [

packages/vitest/snapshot.d.ts

@@ -0,0 +1 @@
+export * from './dist/snapshot.js'

packages/vitest/src/index.ts

@@ -17,6 +17,7 @@ export * from './integrations/chai'
 export * from './integrations/vi'
 export * from './integrations/utils'
 export { inject } from './integrations/inject'
+// TODO: remove in 2.0.0, import from vitest/snapshot directly
 export type { SnapshotEnvironment } from '@vitest/snapshot/environment'
 
 export * from './types'

packages/vitest/src/integrations/snapshot/environments/node.ts

@@ -1,16 +1,13 @@
 import { NodeSnapshotEnvironment } from '@vitest/snapshot/environment'
-import type { WorkerRPC } from '../../../types/worker'
-
-export class VitestSnapshotEnvironment extends NodeSnapshotEnvironment {
-  constructor(private rpc: WorkerRPC) {
-    super()
-  }
+import { getWorkerState } from '../../../utils'
 
+export class VitestNodeSnapshotEnvironment extends NodeSnapshotEnvironment {
   getHeader(): string {
     return `// Vitest Snapshot v${this.getVersion()}, https://vitest.dev/guide/snapshot.html`
   }
 
   resolvePath(filepath: string): Promise<string> {
-    return this.rpc.resolveSnapshotPath(filepath)
+    const rpc = getWorkerState().rpc
+    return rpc.resolveSnapshotPath(filepath)
   }
 }

packages/vitest/src/integrations/snapshot/environments/resolveSnapshotEnvironment.ts

@@ -0,0 +1,18 @@
+import type { SnapshotEnvironment } from '@vitest/snapshot/environment'
+import type { VitestExecutor } from '../../../runtime/execute'
+import type { ResolvedConfig } from '../../../types'
+
+export async function resolveSnapshotEnvironment(
+  config: ResolvedConfig,
+  executor: VitestExecutor,
+): Promise<SnapshotEnvironment> {
+  if (!config.snapshotEnvironment) {
+    const { VitestNodeSnapshotEnvironment } = await import('./node')
+    return new VitestNodeSnapshotEnvironment()
+  }
+
+  const mod = await executor.executeId(config.snapshotEnvironment)
+  if (typeof mod.default !== 'object' || !mod.default)
+    throw new Error('Snapshot environment module must have a default export object with a shape of `SnapshotEnvironment`')
+  return mod.default
+}

packages/vitest/src/node/cli/cli-config.ts

@@ -637,4 +637,5 @@ export const cliOptionsConfig: VitestCLIOptions = {
   deps: null,
   name: null,
   includeTaskLocation: null,
+  snapshotEnvironment: null,
 }