perf: optimize hot paths

sxzz · sxzz · commit 7925dec0f7e3 · 2026-01-04T04:23:11.000+08:00
relate #687
diff --git a/src/config/options.ts b/src/config/options.ts
@@ -318,10 +318,7 @@ function filterEnv(
 ) {
   const env: Record<string, string> = {}
   for (const [key, value] of Object.entries(envDict)) {
-    if (
-      envPrefixes.some((prefix) => key.startsWith(prefix)) &&
-      value !== undefined
-    ) {
+    if (value != null && envPrefixes.some((prefix) => key.startsWith(prefix))) {
       env[key] = value
     }
   }
diff --git a/src/features/external.ts b/src/features/external.ts
@@ -97,7 +97,10 @@ Imported by ${underline(importer)}`,
       }
     }
 
-    if (deps && deps.some((dep) => id === dep || id.startsWith(`${dep}/`))) {
+    if (
+      deps &&
+      (deps.includes(id) || deps.some((dep) => id.startsWith(`${dep}/`)))
+    ) {
       return true
     }
 
diff --git a/src/features/node-protocol.ts b/src/features/node-protocol.ts
@@ -1,52 +1,42 @@
 import { builtinModules } from 'node:module'
 import type { Plugin } from 'rolldown'
 
-const modulesWithoutProtocol = builtinModules.filter(
-  (mod) => !mod.startsWith('node:'),
-)
-
 /**
  * The `node:` protocol was added in Node.js v14.18.0.
  * @see https://nodejs.org/api/esm.html#node-imports
  */
 export function NodeProtocolPlugin(nodeProtocolOption: 'strip' | true): Plugin {
-  if (nodeProtocolOption === 'strip') {
-    const regex = new RegExp(`^node:(${modulesWithoutProtocol.join('|')})$`)
-
-    return {
-      name: 'tsdown:node-protocol:strip',
-      resolveId: {
-        order: 'pre',
-        filter: { id: regex },
-        handler(id) {
-          return {
-            id: id.slice(5), // strip the `node:` prefix
-            external: true,
-            moduleSideEffects: false,
-          }
-        },
-      },
-    }
-  }
-
-  // create regex from builtin modules
-  // filter without `node:` prefix
-  const builtinModulesRegex = new RegExp(
-    `^(${modulesWithoutProtocol.join('|')})$`,
+  const modulesWithoutProtocol = builtinModules.filter(
+    (mod) => !mod.startsWith('node:'),
   )
 
   return {
-    name: 'tsdown:node-protocol:add',
+    name: `tsdown:node-protocol`,
     resolveId: {
       order: 'pre',
-      filter: { id: builtinModulesRegex },
-      handler(id) {
-        return {
-          id: `node:${id}`,
-          external: true,
-          moduleSideEffects: false,
-        }
+      filter: {
+        id:
+          nodeProtocolOption === 'strip'
+            ? new RegExp(`^node:(${modulesWithoutProtocol.join('|')})$`)
+            : new RegExp(`^(${modulesWithoutProtocol.join('|')})$`),
       },
+      handler:
+        nodeProtocolOption === 'strip'
+          ? (id) => {
+              return {
+                // strip the `node:` prefix
+                id: id.slice(5),
+                external: true,
+                moduleSideEffects: false,
+              }
+            }
+          : (id) => {
+              return {
+                id: `node:${id}`,
+                external: true,
+                moduleSideEffects: false,
+              }
+            },
     },
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -318,10 +318,7 @@ function filterEnv(`
`318`	`318`	`) {`
`319`	`319`	`const env: Record<string, string> = {}`
`320`	`320`	`for (const [key, value] of Object.entries(envDict)) {`
`321`		`- if (`
`322`		`- envPrefixes.some((prefix) => key.startsWith(prefix)) &&`
`323`		`- value !== undefined`
`324`		`- ) {`
	`321`	`+ if (value != null && envPrefixes.some((prefix) => key.startsWith(prefix))) {`
`325`	`322`	`env[key] = value`
`326`	`323`	`}`
`327`	`324`	`}`
Original file line number	Diff line number	Diff line change
@@ -97,7 +97,10 @@ Imported by ${underline(importer)}`,
`97`	`97`	`}`
`98`	`98`	`}`
`99`	`99`
`100`		- if (deps && deps.some((dep) => id === dep \|\| id.startsWith(`${dep}/`))) {
	`100`	`+ if (`
	`101`	`+ deps &&`
	`102`	+ (deps.includes(id) \|\| deps.some((dep) => id.startsWith(`${dep}/`)))
	`103`	`+ ) {`
`101`	`104`	`return true`
`102`	`105`	`}`
`103`	`106`