test: stabilize watch hmr baseline reads

Author: sonofmagic

packages/weapp-tailwindcss/test/watch-hmr-class-baseline.unit.test.ts

@@ -76,4 +76,42 @@ describe('watch-hmr class baseline', () => {
     expect(outputs.globalStyle).toContain('.ready')
     expect(session.ensureRunning).toHaveBeenCalled()
   })
+
+  it('accepts an existing empty global style output as a class mutation baseline', async () => {
+    tempDir = await mkdtemp(path.join(os.tmpdir(), 'weapp-tw-class-empty-style-'))
+    const outputWxml = path.join(tempDir, 'index.wxml')
+    const outputJs = path.join(tempDir, 'index.js')
+    const outputStyle = path.join(tempDir, 'app.wxss')
+
+    await Promise.all([
+      writeFile(outputWxml, '<view class="ready"></view>', 'utf8'),
+      writeFile(outputJs, 'export default {}', 'utf8'),
+      writeFile(outputStyle, '', 'utf8'),
+    ])
+
+    const session: WatchSession = {
+      child: {} as WatchSession['child'],
+      ensureRunning: vi.fn(),
+      lastCompileSuccessAt: vi.fn(() => 0),
+      logs: vi.fn(() => ''),
+      stop: vi.fn(async () => {}),
+    }
+    const watchCase = {
+      label: 'demo/weapp-vite-tailwindcss-v4',
+      outputWxml,
+      outputJs,
+    } as WatchCase
+
+    const outputs = await waitForClassMutationBaselineOutputs(
+      watchCase,
+      createOptions(),
+      session,
+      'script',
+      [outputStyle],
+    )
+
+    expect(outputs.wxml).toContain('ready')
+    expect(outputs.js).toContain('export default')
+    expect(outputs.globalStyle).toBe('')
+  })
 })

tools/weapp-tailwindcss-scripts/src/watch-hmr-regression/mutations/class.ts

@@ -32,9 +32,9 @@ import {
   collectPluginProcessMetrics,
   createClassMutationScenario,
   expandOutputFileEntries,
-  hasResolvedOutputFiles,
   readJoinedOutputFiles,
   resolvePreferredRound,
+  waitForClassOutputBaseline,
   waitForCompileSettled,
   waitForMarkerState,
   waitForOutputFilesUpdated,
@@ -73,49 +73,7 @@ export async function waitForClassMutationBaselineOutputs(
   mutationKind: 'template' | 'script' | 'content',
   globalStyleOutputs: string[],
 ): Promise<RoundOutputs> {
-  let resolvedOutputs: RoundOutputs | undefined
-  let lastReason = 'outputs are not ready'
-  const waitStartedAt = Date.now()
-
-  await waitFor(
-    async () => {
-      const [wxml, js, globalStyle, hasGlobalStyleOutputs] = await Promise.all([
-        readFileIfExists(watchCase.outputWxml),
-        readFileIfExists(watchCase.outputJs),
-        readJoinedOutputFiles(globalStyleOutputs),
-        hasResolvedOutputFiles(globalStyleOutputs),
-      ])
-
-      if (wxml && js && hasGlobalStyleOutputs) {
-        resolvedOutputs = {
-          wxml,
-          js,
-          globalStyle,
-        }
-        return true
-      }
-
-      lastReason = [
-        wxml ? undefined : 'wxml',
-        js ? undefined : 'js',
-        hasGlobalStyleOutputs ? undefined : 'global style',
-      ].filter(Boolean).join(', ')
-      return false
-    },
-    {
-      timeoutMs: options.timeoutMs,
-      pollMs: options.pollMs,
-      message: `[${watchCase.label}] baseline outputs are missing for ${mutationKind}: ${lastReason}`,
-      onTick: session.ensureRunning,
-    },
-    waitStartedAt,
-  )
-
-  if (!resolvedOutputs) {
-    throw new Error(`[${watchCase.label}] baseline outputs failed to resolve for ${mutationKind}`)
-  }
-
-  return resolvedOutputs
+  return waitForClassOutputBaseline(watchCase, options, session, mutationKind, globalStyleOutputs)
 }
 
 function collectBgHexTruncationNeedles(classTokens: string[]) {

tools/weapp-tailwindcss-scripts/src/watch-hmr-regression/mutations/class/added-class.ts

@@ -20,6 +20,7 @@ import {
   collectPluginProcessMetrics,
   createClassMutationScenario,
   readJoinedOutputFiles,
+  waitForClassOutputBaseline,
   waitForCompileSettled,
   waitForMarkerState,
   waitForOutputsUpdated,
@@ -152,15 +153,17 @@ export async function runAddedClassMutation(
     verifyClassLiteralIn,
   } = options
 
-  const [baselineWxml, baselineJs, baselineGlobalStyle] = await Promise.all([
-    readFileIfExists(watchCase.outputWxml),
-    readFileIfExists(watchCase.outputJs),
-    readJoinedOutputFiles(globalStyleOutputs),
-  ])
-
-  if (!baselineWxml || !baselineJs || !baselineGlobalStyle) {
-    throw new Error(`[${watchCase.label}] missing baseline outputs for ${mutationKind} added-class mutation`)
-  }
+  const {
+    wxml: baselineWxml,
+    js: baselineJs,
+    globalStyle: baselineGlobalStyle,
+  } = await waitForClassOutputBaseline(
+    watchCase,
+    cliOptions,
+    session,
+    mutationKind,
+    globalStyleOutputs,
+  )
 
   const baseScenario = createClassMutationScenario(
     watchCase,

tools/weapp-tailwindcss-scripts/src/watch-hmr-regression/mutations/class/comment-carrier.ts

@@ -8,11 +8,12 @@ import type {
   WatchSession,
 } from '../../types'
 import { formatPath } from '../../cli'
-import { getMtime, readFileIfExists, writeFilePreserveEol } from '../../text'
+import { getMtime, writeFilePreserveEol } from '../../text'
 import {
   collectPluginProcessMetrics,
   createClassMutationScenario,
   readJoinedOutputFiles,
+  waitForClassOutputBaseline,
   waitForMarkerState,
   waitForOutputsUpdated,
 } from '../shared'
@@ -51,15 +52,17 @@ export async function runCommentCarrierMutation(
     baselineMtime,
   } = options
 
-  const [baselineWxml, baselineJs, baselineGlobalStyle] = await Promise.all([
-    readFileIfExists(watchCase.outputWxml),
-    readFileIfExists(watchCase.outputJs),
-    readJoinedOutputFiles(globalStyleOutputs),
-  ])
-
-  if (!baselineWxml || !baselineJs || !baselineGlobalStyle) {
-    throw new Error(`[${watchCase.label}] missing baseline outputs for script comment-carrier mutation`)
-  }
+  const {
+    wxml: baselineWxml,
+    js: baselineJs,
+    globalStyle: baselineGlobalStyle,
+  } = await waitForClassOutputBaseline(
+    watchCase,
+    cliOptions,
+    session,
+    'script',
+    globalStyleOutputs,
+  )
 
   const mutateCommentCarrier = mutation.mutateCommentCarrier
   if (!mutateCommentCarrier) {

tools/weapp-tailwindcss-scripts/src/watch-hmr-regression/mutations/shared.ts

@@ -247,6 +247,62 @@ export async function waitForOutputsUpdated(
   )
 }
 
+export async function waitForClassOutputBaseline(
+  watchCase: WatchCase,
+  options: CliOptions,
+  session: WatchSession,
+  mutationKind: 'template' | 'script' | 'content',
+  globalStyleOutputs: string[],
+) {
+  let resolvedOutputs: {
+    wxml: string
+    js: string
+    globalStyle: string
+  } | undefined
+  let lastReason = 'outputs are not ready'
+  const waitStartedAt = Date.now()
+
+  await waitFor(
+    async () => {
+      const [wxml, js, globalStyle, hasGlobalStyleOutputs] = await Promise.all([
+        readFileIfExists(watchCase.outputWxml),
+        readFileIfExists(watchCase.outputJs),
+        readJoinedOutputFiles(globalStyleOutputs),
+        hasResolvedOutputFiles(globalStyleOutputs),
+      ])
+
+      if (wxml && js && hasGlobalStyleOutputs) {
+        resolvedOutputs = {
+          wxml,
+          js,
+          globalStyle,
+        }
+        return true
+      }
+
+      lastReason = [
+        wxml ? undefined : 'wxml',
+        js ? undefined : 'js',
+        hasGlobalStyleOutputs ? undefined : 'global style',
+      ].filter(Boolean).join(', ')
+      return false
+    },
+    {
+      timeoutMs: options.timeoutMs,
+      pollMs: options.pollMs,
+      message: `[${watchCase.label}] baseline outputs are missing for ${mutationKind}: ${lastReason}`,
+      onTick: session.ensureRunning,
+    },
+    waitStartedAt,
+  )
+
+  if (!resolvedOutputs) {
+    throw new Error(`[${watchCase.label}] baseline outputs failed to resolve for ${mutationKind}`)
+  }
+
+  return resolvedOutputs
+}
+
 export async function waitForOutputFilesUpdated(
   watchCase: WatchCase,
   files: string[],