wip: improve source map integration w/ vite

package.json

@@ -18,9 +18,10 @@
     "changelog": "conventional-changelog -p angular -i CHANGELOG.md -s -r 2"
   },
   "dependencies": {
+    "@rollup/pluginutils": "^4.1.0",
     "debug": "^4.1.1",
     "hash-sum": "^2.0.0",
-    "@rollup/pluginutils": "^4.1.0"
+    "source-map": "^0.6.1"
   },
   "peerDependencies": {
     "@vue/compiler-sfc": "*"
@@ -38,6 +39,7 @@
     "lint-staged": "^10.1.7",
     "npm-run-all": "^4.1.5",
     "prettier": "^2.0.5",
+    "pug": "^3.0.0",
     "rollup": "^2.7.2",
     "rollup-plugin-postcss": "^3.1.8",
     "ts-jest": "^26.0.0",
@@ -55,7 +57,6 @@
   },
   "prettier": {
     "printWidth": 80,
-    "trailingComma": "es5",
     "semi": false,
     "singleQuote": true
   }

src/handleHotUpdate.ts

@@ -33,7 +33,6 @@ export async function handleHotUpdate(file: string, modules: any[]) {
   const { descriptor } = parse(content, {
     filename: file,
     sourceMap: true,
-    sourceRoot: process.cwd(),
   })
   setDescriptor(file, descriptor)
   setPrevDescriptor(file, prevDescriptor)

src/index.ts

@@ -21,7 +21,6 @@ import { transformStyle } from './style'
 import { createCustomBlockFilter } from './utils/customBlockFilter'
 import { getDescriptor, setDescriptor } from './utils/descriptorCache'
 import { parseVuePartRequest } from './utils/query'
-import { normalizeSourceMap } from './utils/sourceMap'
 import { getResolvedScript } from './script'
 import { handleHotUpdate } from './handleHotUpdate'
 
@@ -131,7 +130,7 @@ export default function PluginVue(userOptions: Partial<Options> = {}): Plugin {
         if (block) {
           return {
             code: block.content,
-            map: normalizeSourceMap(block.map, id),
+            map: block.map as any,
           }
         }
       }
@@ -171,10 +170,10 @@ export default function PluginVue(userOptions: Partial<Options> = {}): Plugin {
         }
         if (query.type === 'template') {
           debug(`transform template (${id})`)
-          return transformTemplateAsModule(code, id, options, query, this)
+          return transformTemplateAsModule(code, options, query, this)
         } else if (query.type === 'style') {
           debug(`transform style (${id})`)
-          return transformStyle(code, id, options, query, isProduction, this)
+          return transformStyle(code, options, query, isProduction, this)
         }
       }
       return null

src/sfcFacade.ts

@@ -14,6 +14,7 @@ import { createRollupError } from './utils/error'
 import { resolveScript } from './script'
 import { transformTemplateInMain } from './template'
 import { isOnlyTemplateChanged } from './handleHotUpdate'
+import { RawSourceMap, SourceMapConsumer, SourceMapGenerator } from 'source-map'
 
 export async function genSfcFacade(
   code: string,
@@ -30,7 +31,6 @@ export async function genSfcFacade(
   const { descriptor, errors } = parse(code, {
     sourceMap: true,
     filename,
-    sourceRoot,
   })
   setDescriptor(filename, descriptor)
 
@@ -68,9 +68,17 @@ export async function genSfcFacade(
     !(descriptor.template && descriptor.template.src)
   const hasTemplateImport = descriptor.template && !useInlineTemplate
 
-  const templateCode = hasTemplateImport
-    ? genTemplateCode(descriptor, scopeId, options, isServer, pluginContext)
-    : ''
+  let templateCode = ''
+  let templateMap
+  if (hasTemplateImport) {
+    ;({ code: templateCode, map: templateMap } = genTemplateCode(
+      descriptor,
+      scopeId,
+      options,
+      isServer,
+      pluginContext
+    ))
+  }
 
   const renderReplace = hasTemplateImport
     ? isServer
@@ -128,9 +136,34 @@ export async function genSfcFacade(
     )
   }
 
+  // if the template is inlined into the main module (indicated by the presence
+  // of templateMap, we need to concatenate the two source maps.
+  let resolvedMap = map
+  if (map && templateMap) {
+    const generator = SourceMapGenerator.fromSourceMap(
+      new SourceMapConsumer(map)
+    )
+    const offset = scriptCode.match(/\r?\n/g)?.length || 1
+    const templateMapConsumer = new SourceMapConsumer(templateMap)
+    templateMapConsumer.eachMapping((m) => {
+      generator.addMapping({
+        source: m.source,
+        original: { line: m.originalLine, column: m.originalColumn },
+        generated: {
+          line: m.generatedLine + offset,
+          column: m.generatedColumn,
+        },
+      })
+    })
+    resolvedMap = (generator as any).toJSON()
+    // if this is a template only update, we will be reusing a cached version
+    // of the main module compile result, which has outdated sourcesContent.
+    resolvedMap.sourcesContent = templateMap.sourcesContent
+  }
+
   return {
     code: output.join('\n'),
-    map: map || {
+    map: resolvedMap || {
       mappings: '',
     },
   }
@@ -146,6 +179,9 @@ function genTemplateCode(
   const renderFnName = isServer ? 'ssrRender' : 'render'
   const template = descriptor.template!
 
+  // If the template is not using pre-processor AND is not using external src,
+  // compile and inline it directly in the main module. When served in vite this
+  // saves an extra request per SFC which can improve load performance.
   if (!template.lang && !template.src) {
     return transformTemplateInMain(
       template.content,
@@ -160,9 +196,12 @@ function genTemplateCode(
     const srcQuery = template.src ? `&src` : ``
     const attrsQuery = attrsToQuery(template.attrs, 'js', true)
     const query = `?vue&type=template${idQuery}${srcQuery}${attrsQuery}`
-    return `import { ${renderFnName} as _sfc_${renderFnName} } from ${JSON.stringify(
-      src + query
-    )}`
+    return {
+      code: `import { ${renderFnName} as _sfc_${renderFnName} } from ${JSON.stringify(
+        src + query
+      )}`,
+      map: undefined,
+    }
   }
 }
 
@@ -173,7 +212,10 @@ async function genScriptCode(
   isServer: boolean,
   options: Options,
   pluginContext: TransformPluginContext
-) {
+): Promise<{
+  code: string
+  map: RawSourceMap
+}> {
   let scriptCode = `const _sfc_main = {}`
   let map
   const script = resolveScript(
@@ -185,7 +227,8 @@ async function genScriptCode(
     pluginContext
   )
   if (script) {
-    // js or ts can be directly placed in the main module
+    // If the script is js/ts and has no external src, it can be directly placed
+    // in the main module.
     if (
       (!script.lang ||
         (script.lang === 'ts' && (pluginContext as any).server)) &&

src/style.ts

@@ -6,11 +6,9 @@ import { TransformPluginContext } from 'rollup'
 import { Options } from '.'
 import { getDescriptor } from './utils/descriptorCache'
 import { StyleBlockQuery } from './utils/query'
-import { normalizeSourceMap } from './utils/sourceMap'
 
 export async function transformStyle(
   code: string,
-  request: string,
   options: Options,
   query: StyleBlockQuery,
   isProduction: boolean,
@@ -85,7 +83,7 @@ export async function transformStyle(
   } else {
     return {
       code: result.code,
-      map: normalizeSourceMap(result.map!, request),
+      map: result.map as any,
     }
   }
 }

src/template.ts

@@ -9,11 +9,9 @@ import { getResolvedScript } from './script'
 import { getDescriptor } from './utils/descriptorCache'
 import { createRollupError } from './utils/error'
 import { TemplateBlockQuery } from './utils/query'
-import { normalizeSourceMap } from './utils/sourceMap'
 
 export function transformTemplateAsModule(
   code: string,
-  request: string,
   options: Options,
   query: TemplateBlockQuery,
   pluginContext: TransformPluginContext
@@ -37,7 +35,7 @@ export function transformTemplateAsModule(
 
   return {
     code: returnCode,
-    map: normalizeSourceMap(result.map!, request),
+    map: result.map as any,
   }
 }
 
@@ -52,11 +50,13 @@ export function transformTemplateInMain(
   pluginContext: PluginContext
 ) {
   const result = compileTemplate(code, descriptor, id, options, pluginContext)
-  // TODO figure out how to merge the source map with the script map
-  return result.code.replace(
-    /\nexport (function|const) (render|ssrRender)/,
-    '\n$1 _sfc_$2'
-  )
+  return {
+    ...result,
+    code: result.code.replace(
+      /\nexport (function|const) (render|ssrRender)/,
+      '\n$1 _sfc_$2'
+    ),
+  }
 }
 
 export function compileTemplate(
@@ -67,8 +67,9 @@ export function compileTemplate(
   pluginContext: PluginContext
 ) {
   const filename = descriptor.filename
+  const compileOptions = getTemplateCompilerOptions(options, descriptor, id)
   const result = compile({
-    ...getTemplateCompilerOptions(options, descriptor, id),
+    ...compileOptions,
     id,
     source: code,
     filename,