fix(cordis): make config reload transactional

packages/ui/app-boot/tests/hmr-config.spec.ts

@@ -0,0 +1,142 @@
+import { mkdirSync, mkdtempSync, readFileSync, unlinkSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { pathToFileURL } from 'node:url'
+import { Context } from 'cordis'
+import Hmr from '@cordisjs/plugin-hmr'
+import Loader from '@cordisjs/plugin-loader'
+import Timer from '@cordisjs/plugin-timer'
+import { describe, expect, it } from 'vitest'
+
+async function bootHmr(dir: string): Promise<Context> {
+  const ctx = new Context()
+  ctx.baseUrl = pathToFileURL(dir).href + '/'
+  await ctx.plugin(Loader)
+  await ctx.plugin(Timer)
+  await ctx.plugin(Hmr, { root: [], ignored: [], debounce: 0 })
+  return ctx
+}
+
+async function eventually(test: () => boolean, message: string): Promise<void> {
+  const deadline = Date.now() + 10_000
+  while (!test()) {
+    if (Date.now() >= deadline) throw new Error(message)
+    await new Promise(resolve => setTimeout(resolve, 10))
+  }
+}
+
+describe('HMR exact config paths', () => {
+  it('observes add, change, and unlink outside its module roots', { timeout: 20_000 }, async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'dsh-hmr-config-'))
+    const filename = join(dir, 'plugins.yml')
+    const ctx = await bootHmr(dir)
+    const observed: string[] = []
+    try {
+      await ctx.hmr.registerConfig(filename, () => {
+        try {
+          observed.push(readFileSync(filename, 'utf8'))
+        } catch (error) {
+          if ((error as NodeJS.ErrnoException).code !== 'ENOENT') throw error
+          observed.push('missing')
+        }
+      })
+
+      writeFileSync(filename, 'one', { flag: 'wx' })
+      await eventually(() => observed.includes('one'), 'HMR did not observe config creation')
+      writeFileSync(filename, 'two')
+      await eventually(() => observed.includes('two'), 'HMR did not observe config change')
+      unlinkSync(filename)
+      await eventually(() => observed.includes('missing'), 'HMR did not observe config removal')
+    } finally {
+      await ctx.fiber.dispose()
+    }
+  })
+
+  it('observes creation when the config parent did not exist at registration', { timeout: 20_000 }, async () => {
+    const root = mkdtempSync(join(tmpdir(), 'dsh-hmr-config-'))
+    const dir = join(root, 'later')
+    const filename = join(dir, 'plugins.yml')
+    const ctx = await bootHmr(root)
+    const observed: string[] = []
+    try {
+      await ctx.hmr.registerConfig(filename, () => {
+        observed.push(readFileSync(filename, 'utf8'))
+      })
+      mkdirSync(dir)
+      writeFileSync(filename, 'created')
+      await eventually(() => observed.includes('created'), 'HMR did not observe config creation under a new parent')
+    } finally {
+      await ctx.fiber.dispose()
+    }
+  })
+
+  it('serializes refreshes and waits for them during disposal', { timeout: 20_000 }, async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'dsh-hmr-config-'))
+    const filename = join(dir, 'plugins.yml')
+    writeFileSync(filename, 'one')
+    const ctx = await bootHmr(dir)
+    const started = Promise.withResolvers<undefined>()
+    const release = Promise.withResolvers<undefined>()
+    const observed: string[] = []
+    let active = 0
+    let maxActive = 0
+    try {
+      const dispose = await ctx.hmr.registerConfig(filename, async () => {
+        active += 1
+        maxActive = Math.max(maxActive, active)
+        observed.push(readFileSync(filename, 'utf8'))
+        if (observed.length === 1) {
+          started.resolve(undefined)
+          await release.promise
+        }
+        active -= 1
+      })
+      await started.promise
+      writeFileSync(filename, 'two')
+      // Chokidar coalesces atomic writes for 100 ms by default. Wait beyond
+      // that window so this edit is queued before registration disposal.
+      await new Promise(resolve => setTimeout(resolve, 250))
+
+      let disposed = false
+      const disposal = dispose().then(() => { disposed = true })
+      await Promise.resolve()
+      expect(disposed).toBe(false)
+      release.resolve(undefined)
+      await disposal
+      expect(maxActive).toBe(1)
+      expect(observed).toEqual(['one', 'two'])
+    } finally {
+      release.resolve(undefined)
+      await ctx.fiber.dispose()
+    }
+  })
+
+  it('normalizes refresh failures and broadcasts them without escaping the watcher', { timeout: 20_000 }, async () => {
+    const dir = mkdtempSync(join(tmpdir(), 'dsh-hmr-config-'))
+    const filename = join(dir, 'plugins.yml')
+    const ctx = await bootHmr(dir)
+    const failure = Promise.withResolvers<{ filename: string; error: Error }>()
+    let failureCount = 0
+    try {
+      ctx.on('hmr/config-update-failed', () => {
+        throw new Error('observer failed')
+      })
+      ctx.on('hmr/config-update-failed', (failedFilename, error) => {
+        failureCount += 1
+        failure.resolve({ filename: failedFilename, error })
+      })
+      await ctx.hmr.registerConfig(filename, () => { throw 42 })
+      writeFileSync(filename, 'invalid')
+
+      const observed = await failure.promise
+      expect(observed.filename).toBe(filename)
+      expect(observed.error).toBeInstanceOf(Error)
+      expect(observed.error.message).toBe('42')
+
+      writeFileSync(filename, 'invalid again')
+      await eventually(() => failureCount === 2, 'HMR stopped broadcasting after an observer rejected')
+    } finally {
+      await ctx.fiber.dispose()
+    }
+  })
+})