From 1596f425233ce18d36bd415dd6fa6b7a2869f8bd Mon Sep 17 00:00:00 2001
From: patak-dev <matias.capeletto@gmail.com>
Date: Sun, 26 Jun 2022 12:38:44 +0200
Subject: [PATCH] perf: avoid sourcemap generation during dev for line-stable
 transforms

---
 packages/vite/src/node/plugins/assetImportMetaUrl.ts |  4 ++--
 packages/vite/src/node/plugins/dynamicImportVars.ts  |  4 ++--
 packages/vite/src/node/plugins/importAnalysis.ts     |  4 ++--
 packages/vite/src/node/plugins/importMetaGlob.ts     |  4 ++--
 .../vite/src/node/plugins/workerImportMetaUrl.ts     |  4 ++--
 packages/vite/src/node/utils.ts                      | 12 ++++++++----
 6 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/packages/vite/src/node/plugins/assetImportMetaUrl.ts b/packages/vite/src/node/plugins/assetImportMetaUrl.ts
index af3fa325bfce03..6d7a657706cf9c 100644
--- a/packages/vite/src/node/plugins/assetImportMetaUrl.ts
+++ b/packages/vite/src/node/plugins/assetImportMetaUrl.ts
@@ -3,7 +3,7 @@ import MagicString from 'magic-string'
 import { stripLiteral } from 'strip-literal'
 import type { Plugin } from '../plugin'
 import type { ResolvedConfig } from '../config'
-import { transformResult } from '../utils'
+import { transformStableResult } from '../utils'
 import { fileToUrl } from './asset'
 import { preloadHelperId } from './importAnalysisBuild'
 
@@ -81,7 +81,7 @@ export function assetImportMetaUrlPlugin(config: ResolvedConfig): Plugin {
           )
         }
         if (s) {
-          return transformResult(s, id, config)
+          return transformStableResult(s, id, config)
         }
       }
       return null
diff --git a/packages/vite/src/node/plugins/dynamicImportVars.ts b/packages/vite/src/node/plugins/dynamicImportVars.ts
index 7093ded9253a39..97f605c1758d53 100644
--- a/packages/vite/src/node/plugins/dynamicImportVars.ts
+++ b/packages/vite/src/node/plugins/dynamicImportVars.ts
@@ -11,7 +11,7 @@ import {
   normalizePath,
   parseRequest,
   requestQuerySplitRE,
-  transformResult
+  transformStableResult
 } from '../utils'
 
 export const dynamicImportHelperId = '/@vite/dynamic-import-helper'
@@ -209,7 +209,7 @@ export function dynamicImportVarsPlugin(config: ResolvedConfig): Plugin {
             `import __variableDynamicImportRuntimeHelper from "${dynamicImportHelperId}";`
           )
         }
-        return transformResult(s, importer, config)
+        return transformStableResult(s, importer, config)
       }
     }
   }
diff --git a/packages/vite/src/node/plugins/importAnalysis.ts b/packages/vite/src/node/plugins/importAnalysis.ts
index c7b4d5c8bb3f1b..9a39c792388400 100644
--- a/packages/vite/src/node/plugins/importAnalysis.ts
+++ b/packages/vite/src/node/plugins/importAnalysis.ts
@@ -40,7 +40,7 @@ import {
   removeImportQuery,
   stripBomTag,
   timeFrom,
-  transformResult,
+  transformStableResult,
   unwrapId
 } from '../utils'
 import type { ResolvedConfig } from '../config'
@@ -711,7 +711,7 @@ export function importAnalysisPlugin(config: ResolvedConfig): Plugin {
       }
 
       if (s) {
-        return transformResult(s, importer, config)
+        return transformStableResult(s, importer, config)
       } else {
         return source
       }
diff --git a/packages/vite/src/node/plugins/importMetaGlob.ts b/packages/vite/src/node/plugins/importMetaGlob.ts
index 661093676626e6..ae8bd2963de573 100644
--- a/packages/vite/src/node/plugins/importMetaGlob.ts
+++ b/packages/vite/src/node/plugins/importMetaGlob.ts
@@ -17,7 +17,7 @@ import type { Plugin } from '../plugin'
 import type { ViteDevServer } from '../server'
 import type { ModuleNode } from '../server/moduleGraph'
 import type { ResolvedConfig } from '../config'
-import { normalizePath, slash, transformResult } from '../utils'
+import { normalizePath, slash, transformStableResult } from '../utils'
 
 const { isMatch, scan } = micromatch
 
@@ -75,7 +75,7 @@ export function importGlobPlugin(config: ResolvedConfig): Plugin {
             server!.watcher.add(dirname(file))
           })
         }
-        return transformResult(result.s, id, config)
+        return transformStableResult(result.s, id, config)
       }
     }
   }
diff --git a/packages/vite/src/node/plugins/workerImportMetaUrl.ts b/packages/vite/src/node/plugins/workerImportMetaUrl.ts
index c88046465f0f42..1b05e6d4a137e1 100644
--- a/packages/vite/src/node/plugins/workerImportMetaUrl.ts
+++ b/packages/vite/src/node/plugins/workerImportMetaUrl.ts
@@ -10,7 +10,7 @@ import {
   injectQuery,
   normalizePath,
   parseRequest,
-  transformResult
+  transformStableResult
 } from '../utils'
 import { getDepsOptimizer } from '../optimizer'
 import type { WorkerType } from './worker'
@@ -136,7 +136,7 @@ export function workerImportMetaUrlPlugin(config: ResolvedConfig): Plugin {
         }
 
         if (s) {
-          return transformResult(s, id, config)
+          return transformStableResult(s, id, config)
         }
 
         return null
diff --git a/packages/vite/src/node/utils.ts b/packages/vite/src/node/utils.ts
index c554fa0396f87b..502f2078cefd5c 100644
--- a/packages/vite/src/node/utils.ts
+++ b/packages/vite/src/node/utils.ts
@@ -1028,16 +1028,20 @@ function normalizeSingleAlias({
   return alias
 }
 
-export function transformResult(
+/**
+ * Transforms transpiled code result where line numbers aren't altered,
+ * so we can skip sourcemap generation during dev
+ */
+export function transformStableResult(
   s: MagicString,
   id: string,
   config: ResolvedConfig
 ): TransformResult {
-  const isBuild = config.command === 'build'
-  const needSourceMap = !isBuild || config.build.sourcemap
   return {
     code: s.toString(),
-    map: needSourceMap ? s.generateMap({ hires: true, source: id }) : null
+    map: config.build.sourcemap
+      ? s.generateMap({ hires: true, source: id })
+      : null
   }
 }