fix: use relative paths in source map's "sources" field

packages/vite-node/src/server.ts

@@ -119,11 +119,11 @@ export class ViteNodeServer {
     return this.fetchPromiseMap.get(id)!
   }
 
-  async transformRequest(id: string) {
+  async transformRequest(id: string, filepath = id) {
     // reuse transform for concurrent requests
     if (!this.transformPromiseMap.has(id)) {
       this.transformPromiseMap.set(id,
-        this._transformRequest(id)
+        this._transformRequest(id, filepath)
           .finally(() => {
             this.transformPromiseMap.delete(id)
           }),
@@ -177,7 +177,7 @@ export class ViteNodeServer {
     }
     else {
       const start = performance.now()
-      const r = await this._transformRequest(id, transformMode)
+      const r = await this._transformRequest(id, filePath, transformMode)
       duration = performance.now() - start
       result = { code: r?.code, map: r?.map as any }
     }
@@ -191,15 +191,15 @@ export class ViteNodeServer {
     return result
   }
 
-  protected async processTransformResult(id: string, result: TransformResult) {
-    const mod = this.server.moduleGraph.getModuleById(id)
+  protected async processTransformResult(filepath: string, result: TransformResult) {
+    const mod = this.server.moduleGraph.getModuleById(filepath)
     return withInlineSourcemap(result, {
-      filepath: mod?.file || id,
+      filepath: mod?.file || filepath,
       root: this.server.config.root,
     })
   }
 
-  private async _transformRequest(id: string, customTransformMode?: 'web' | 'ssr') {
+  private async _transformRequest(id: string, filepath: string, customTransformMode?: 'web' | 'ssr') {
     debugRequest(id)
 
     let result: TransformResult | null = null
@@ -225,7 +225,7 @@ export class ViteNodeServer {
 
     const sourcemap = this.options.sourcemap ?? 'inline'
     if (sourcemap === 'inline' && result && !id.includes('node_modules'))
-      result = await this.processTransformResult(id, result)
+      result = await this.processTransformResult(filepath, result)
 
     if (this.options.debug?.dumpModules)
       await this.debugger?.dumpFile(id, result)

packages/vite-node/src/source-map.ts

@@ -1,5 +1,5 @@
 import type { TransformResult } from 'vite'
-import { dirname, isAbsolute, join, resolve } from 'pathe'
+import { dirname, isAbsolute, relative, resolve } from 'pathe'
 import type { EncodedSourceMap } from '@jridgewell/trace-mapping'
 import { install } from './source-map-handler'
 
@@ -24,17 +24,19 @@ export function withInlineSourcemap(result: TransformResult, options: {
   if (!map || code.includes(VITE_NODE_SOURCEMAPPING_SOURCE))
     return result
 
-  // sources path from `ViteDevServer` may be not a valid filesystem path (eg. /src/main.js),
-  // so we try to convert them to valid filesystem path
   map.sources = map.sources?.map((source) => {
     if (!source)
       return source
-    // make source absolute again, it might not be relative to the root, but to the "source root"
-    // https://github.com/bmeurer/vite/blob/172c3e36226ec4bdf2c9d5f8fa84310bde3fec54/packages/vite/src/node/server/transformRequest.ts#L281
-    if (!isAbsolute(source))
-      return resolve(dirname(options.filepath), source)
-    if (!source.startsWith(options.root))
-      return join(options.root, source)
+    // sometimes files here are absolute,
+    // but they are considered absolute to the server url, not the file system
+    // this is a bug in Vite
+    // all files should be either absolute to the file system or relative to the source map file
+    if (isAbsolute(source)) {
+      const actualPath = (!source.startsWith(options.root) && source.startsWith('/'))
+        ? resolve(options.root, source.slice(1))
+        : source
+      return relative(dirname(options.filepath), actualPath)
+    }
     return source
   })
 

packages/vitest/src/typecheck/collect.ts

@@ -40,7 +40,7 @@ export interface FileInformation {
 }
 
 export async function collectTests(ctx: WorkspaceProject, filepath: string): Promise<null | FileInformation> {
-  const request = await ctx.vitenode.transformRequest(filepath)
+  const request = await ctx.vitenode.transformRequest(filepath, filepath)
   if (!request)
     return null
   const ast = parseAst(request.code, {

packages/vitest/src/typecheck/typechecker.ts

@@ -1,7 +1,7 @@
 import { rm } from 'node:fs/promises'
 import type { ExecaChildProcess } from 'execa'
 import { execa } from 'execa'
-import { extname, resolve } from 'pathe'
+import { basename, extname, resolve } from 'pathe'
 import { SourceMapConsumer } from 'source-map'
 import { getTasks } from '../utils'
 import { ensurePackageInstalled } from '../node/pkg'
@@ -132,7 +132,7 @@ export class Typechecker {
         const processedPos = mapConsumer?.generatedPositionFor({
           line: originalError.line,
           column: originalError.column,
-          source: path,
+          source: basename(path),
         }) || originalError
         const line = processedPos.line ?? originalError.line
         const column = processedPos.column ?? originalError.column

test/vite-node/test/server.test.ts

@@ -42,6 +42,6 @@ describe('server works correctly', async () => {
     const sourceMap = extractSourceMap(fetchResult.code!)
 
     // expect got sourcemap source in a valid filesystem path
-    expect(sourceMap?.sources[0]).toBe(resolve(__dirname, '../src/foo.js'))
+    expect(sourceMap?.sources[0]).toBe('foo.js')
   })
 })