perf(weapp-tailwindcss): 延迟构建标签忽略匹配器

Author: sonofmagic

packages/weapp-tailwindcss/src/js/babel.ts

@@ -16,6 +16,18 @@ import { createTaggedTemplateIgnore } from './taggedTemplateIgnore'
 
 const EXPRESSION_WRAPPER_PREFIX = '(\n'
 const EXPRESSION_WRAPPER_SUFFIX = '\n)'
+const ignoredTaggedTemplateMatcherCache = new WeakMap<IJsHandlerOptions, ReturnType<typeof createNameMatcher>>()
+
+function getIgnoredTaggedTemplateMatcher(options: IJsHandlerOptions) {
+  const cached = ignoredTaggedTemplateMatcherCache.get(options)
+  if (cached) {
+    return cached
+  }
+
+  const created = createNameMatcher(options.ignoreTaggedTemplateExpressionIdentifiers, { exact: true })
+  ignoredTaggedTemplateMatcherCache.set(options, created)
+  return created
+}
 
 export function analyzeSource(
   ast: ParseResult<File>,
@@ -35,11 +47,17 @@ export function analyzeSource(
     },
   )
 
-  const isIgnoredTaggedTemplate = createNameMatcher(options.ignoreTaggedTemplateExpressionIdentifiers, { exact: true })
-  const taggedTemplateIgnore = createTaggedTemplateIgnore({
-    matcher: isIgnoredTaggedTemplate,
-    names: options.ignoreTaggedTemplateExpressionIdentifiers,
-  })
+  let taggedTemplateIgnore: ReturnType<typeof createTaggedTemplateIgnore> | undefined
+
+  function getTaggedTemplateIgnore() {
+    if (!taggedTemplateIgnore) {
+      taggedTemplateIgnore = createTaggedTemplateIgnore({
+        matcher: getIgnoredTaggedTemplateMatcher(options),
+        names: options.ignoreTaggedTemplateExpressionIdentifiers,
+      })
+    }
+    return taggedTemplateIgnore
+  }
 
   // 仅在需要时才构建作用域信息（例如需要遍历调用表达式的实参）。
   const needScope = Boolean(options.ignoreCallExpressionIdentifiers && options.ignoreCallExpressionIdentifiers.length > 0)
@@ -70,7 +88,7 @@ export function analyzeSource(
           }
           if (ppp.isTaggedTemplateExpression()) {
             const tagPath = ppp.get('tag') as NodePath<Node>
-            if (taggedTemplateIgnore.shouldIgnore(tagPath)) {
+            if (getTaggedTemplateIgnore().shouldIgnore(tagPath)) {
               return
             }
           }

packages/weapp-tailwindcss/test/js/babel-branches.test.ts

@@ -5,6 +5,7 @@ import { MappingChars2String } from '@weapp-core/escape'
 import { describe, expect, it, vi } from 'vitest'
 import { parse, traverse } from '@/babel'
 import * as babel from '@/js/babel'
+import * as nameMatcher from '@/utils/nameMatcher'
 
 function prepareEval(code: string) {
   const ast = parse(code, { sourceType: 'module' })
@@ -153,6 +154,32 @@ describe('babel helpers branch coverage', () => {
     expect(analysis.targetPaths).toHaveLength(1)
   })
 
+  it('does not build ignore matchers when tagged templates are absent', () => {
+    const spy = vi.spyOn(nameMatcher, 'createNameMatcher')
+    const ast = parse('const cls = `w-[100px]`', { sourceType: 'module' })
+
+    const analysis = babel.analyzeSource(ast, {
+      ignoreTaggedTemplateExpressionIdentifiers: ['styled'],
+    })
+
+    expect(analysis.targetPaths).toHaveLength(1)
+    expect(spy).not.toHaveBeenCalled()
+  })
+
+  it('reuses ignored tag matchers for the same options object', () => {
+    const spy = vi.spyOn(nameMatcher, 'createNameMatcher')
+    const options = {
+      ignoreTaggedTemplateExpressionIdentifiers: ['styled'],
+    }
+
+    const firstAst = parse('styled`w-[100px]`', { sourceType: 'module' })
+    const secondAst = parse('styled`w-[200px]`', { sourceType: 'module' })
+
+    expect(babel.analyzeSource(firstAst, options).targetPaths).toHaveLength(0)
+    expect(babel.analyzeSource(secondAst, options).targetPaths).toHaveLength(0)
+    expect(spy).toHaveBeenCalledTimes(1)
+  })
+
   it('falls back to an empty original value for unexpected eval nodes', () => {
     const rawSource = 'eval(`__coverage__` )'
     const ast = parse(rawSource, { sourceType: 'module' })