fix: load source map from sourceMappingURL comment (#1327)

..and feed it into the `transform` hook.

packages/vite/package.json

@@ -59,6 +59,7 @@
     "@rollup/plugin-typescript": "^8.0.0",
     "@rollup/pluginutils": "^4.1.0",
     "@types/clean-css": "^4.2.3",
+    "@types/convert-source-map": "^1.5.1",
     "@types/debug": "^4.1.5",
     "@types/es-module-lexer": "^0.3.0",
     "@types/estree": "^0.0.45",
@@ -77,6 +78,7 @@
     "clean-css": "^4.2.3",
     "connect": "^3.7.0",
     "connect-history-api-fallback": "^1.6.0",
+    "convert-source-map": "^1.7.0",
     "cors": "^2.8.5",
     "debug": "^4.3.1",
     "dotenv": "^8.2.0",

packages/vite/src/node/server/transformRequest.ts

@@ -1,5 +1,7 @@
 import { promises as fs } from 'fs'
+import path from 'path'
 import getEtag from 'etag'
+import * as convertSourceMap from 'convert-source-map'
 import { SourceDescription, SourceMap } from 'rollup'
 import { ViteDevServer } from '..'
 import chalk from 'chalk'
@@ -58,6 +60,12 @@ export async function transformRequest(
         throw e
       }
     }
+    if (code) {
+      map = (
+        convertSourceMap.fromSource(code) ||
+        convertSourceMap.fromMapFileSource(code, path.dirname(file))
+      )?.toObject()
+    }
   } else {
     isDebug && debugLoad(`${timeFrom(loadStart)} [plugin] ${prettyUrl}`)
     if (typeof loadResult === 'object') {
@@ -80,7 +88,7 @@ export async function transformRequest(
 
   // transform
   const transformStart = Date.now()
-  const transformResult = await pluginContainer.transform(code, id)
+  const transformResult = await pluginContainer.transform(code, id, map)
   if (
     transformResult == null ||
     (typeof transformResult === 'object' && transformResult.code == null)