perf(hmr): poll client bundles only

packages/client/hmr/src/index.ts

@@ -1,7 +1,7 @@
 /**
  * HMR plugin, node half: the host end of the dev reload chain. One interval
- * stat-polls every graph row's client bundle and optional source map (polling
- * by design: network mounts deliver no inotify events), reports changes through
+ * stat-polls every graph row's client bundle (polling by design: network mounts
+ * deliver no inotify events), reports changes through
  * `clientModuleHost.rebuilt(id)`, and serves the `/plugins/events` SSE channel
  * broadcasting graph/rebuilt frames to the browser half (src/client/).
  * The web bundle mounts this row unconditionally: without a rebuild
@@ -42,30 +42,22 @@ function sseData(frame: PluginsEventFrame): string {
   return `data: ${JSON.stringify(frame)}\n\n`
 }
 
-type WatchedArtifactStat = Omit<ClientArtifactBaseline, 'path'>
+type WatchedBundleStat = Omit<ClientArtifactBaseline, 'path'>
 
 type WatchedBundle = {
   -readonly [K in keyof ClientArtifactBaseline]: ClientArtifactBaseline[K]
 } & { dirty: boolean }
 
-/** Snapshot the bundle plus its optional development source map. */
-function artifactStat(path: string): WatchedArtifactStat {
+/** Snapshot the executable bundle metadata that drives reloads. */
+function bundleStat(path: string): WatchedBundleStat {
   const bundle = statSync(path)
-  try {
-    const map = statSync(`${path}.map`)
-    return { mtimeMs: bundle.mtimeMs, size: bundle.size, mapMtimeMs: map.mtimeMs, mapSize: map.size }
-  } catch (error) {
-    if ((error as NodeJS.ErrnoException).code !== 'ENOENT') throw error
-    return { mtimeMs: bundle.mtimeMs, size: bundle.size, mapMtimeMs: null, mapSize: null }
-  }
+  return { mtimeMs: bundle.mtimeMs, size: bundle.size }
 }
 
-/** Whether neither served artifact changed since the last successful re-hash. */
-function sameArtifactStat(left: WatchedArtifactStat, right: WatchedArtifactStat): boolean {
+/** Whether the executable bundle is unchanged since the last successful re-hash. */
+function sameBundleStat(left: WatchedBundleStat, right: WatchedBundleStat): boolean {
   return left.mtimeMs === right.mtimeMs
     && left.size === right.size
-    && left.mapMtimeMs === right.mapMtimeMs
-    && left.mapSize === right.mapSize
 }
 
 /**
@@ -80,7 +72,7 @@ export function apply(ctx: Context, config: Config): void {
   // --- bundle watch: one HMR-owned stat poll ------------------------------
   const watched = new Map<string, WatchedBundle>()
 
-  const rehash = (id: string, watch: WatchedBundle, current: WatchedArtifactStat): void => {
+  const rehash = (id: string, watch: WatchedBundle, current: WatchedBundleStat): void => {
     try {
       // rebuilt() replaces the opaque startup rev on its first call; later
       // calls stay silent when the content hash is unchanged.
@@ -95,17 +87,15 @@ export function apply(ctx: Context, config: Config): void {
     }
     watch.mtimeMs = current.mtimeMs
     watch.size = current.size
-    watch.mapMtimeMs = current.mapMtimeMs
-    watch.mapSize = current.mapSize
     watch.dirty = false
   }
 
   const watchRow = (id: string, baseline: ClientArtifactBaseline): void => {
     const watch: WatchedBundle = { ...baseline, dirty: false }
     watched.set(id, watch)
-    let current: WatchedArtifactStat
+    let current: WatchedBundleStat
     try {
-      current = artifactStat(baseline.path)
+      current = bundleStat(baseline.path)
     } catch (error) {
       watch.dirty = true
       if ((error as NodeJS.ErrnoException).code !== 'ENOENT') ctx.logger.warn(error)
@@ -113,20 +103,20 @@ export function apply(ctx: Context, config: Config): void {
     }
     // The module host captured its baseline before reading the bytes in the
     // startup batch. Only a mismatch crosses into the content-hash path.
-    if (!sameArtifactStat(current, watch)) rehash(id, watch, current)
+    if (!sameBundleStat(current, watch)) rehash(id, watch, current)
   }
 
   const pollWatches = (): void => {
     for (const [id, watch] of watched) {
-      let current: WatchedArtifactStat
+      let current: WatchedBundleStat
       try {
-        current = artifactStat(watch.path)
+        current = bundleStat(watch.path)
       } catch (error) {
         watch.dirty = true
         if ((error as NodeJS.ErrnoException).code !== 'ENOENT') ctx.logger.warn(error)
         continue
       }
-      if (!watch.dirty && sameArtifactStat(current, watch)) continue
+      if (!watch.dirty && sameBundleStat(current, watch)) continue
       // Stat-before-hash preserves a detectable older baseline for writes that
       // land during hashing. Repeated stat changes heal a torn read.
       rehash(id, watch, current)

packages/client/hmr/tests/node-half.client.spec.ts

@@ -31,19 +31,7 @@ interface FakeHostOptions {
 
 function artifactBaseline(path: string): ClientArtifactBaseline {
   const bundle = statSync(path)
-  try {
-    const sourceMap = statSync(`${path}.map`)
-    return {
-      path,
-      mtimeMs: bundle.mtimeMs,
-      size: bundle.size,
-      mapMtimeMs: sourceMap.mtimeMs,
-      mapSize: sourceMap.size,
-    }
-  } catch (error) {
-    if ((error as NodeJS.ErrnoException).code !== 'ENOENT') throw error
-    return { path, mtimeMs: bundle.mtimeMs, size: bundle.size, mapMtimeMs: null, mapSize: null }
-  }
+  return { path, mtimeMs: bundle.mtimeMs, size: bundle.size }
 }
 
 function fakeClientModuleHost(rows: Map<string, string>, options: FakeHostOptions = {}): FakeHost {
@@ -111,7 +99,7 @@ async function mount(clientModuleHost: FakeHost, webServer: WebServer) {
 }
 
 describe('hmr node half', () => {
-  it('watches graph bundles, reports stat changes, and unwatches on dispose', async () => {
+  it('watches graph bundles, ignores map-only changes, and unwatches on dispose', async () => {
     const bundle = join(dir, 'a.js')
     writeFileSync(bundle, 'v1')
     const clientModuleHost = fakeClientModuleHost(new Map([['pkg-a', bundle]]))
@@ -130,13 +118,17 @@ describe('hmr node half', () => {
     clientModuleHost.rebuiltCalls.length = 0
     await new Promise(resolve => setTimeout(resolve, POLL_MS * 2))
     writeFileSync(`${bundle}.map`, '{"version":3}')
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 3))
+    expect(clientModuleHost.rebuiltCalls).toEqual([])
+
+    writeFileSync(bundle, 'v3-even-longer')
     await vi.waitFor(() => { expect(clientModuleHost.rebuiltCalls).toContain('pkg-a') }, { timeout: 3_000 })
 
     await fiber.dispose()
     expect(routes).toHaveLength(0)
     // Watcher gone: further file changes report nothing.
     clientModuleHost.rebuiltCalls.length = 0
-    writeFileSync(bundle, 'v3-even-longer')
+    writeFileSync(bundle, 'v4-after-dispose')
     await new Promise(resolve => setTimeout(resolve, POLL_MS * 4))
     expect(clientModuleHost.rebuiltCalls).toHaveLength(0)
   })

packages/client/modules/src/index.ts

@@ -23,7 +23,7 @@
  */
 
 import { createHash, randomBytes } from 'node:crypto'
-import { readFileSync, statSync, type Stats } from 'node:fs'
+import { readFileSync, statSync } from 'node:fs'
 import type { IncomingMessage, ServerResponse } from 'node:http'
 import { createRequire } from 'node:module'
 import { dirname, join } from 'node:path'
@@ -78,10 +78,6 @@ export interface ClientArtifactBaseline {
   readonly mtimeMs: number
   /** Bundle size in bytes. */
   readonly size: number
-  /** Source-map modification time, or null when no map was observable. */
-  readonly mapMtimeMs: number | null
-  /** Source-map size in bytes, or null when no map was observable. */
-  readonly mapSize: number | null
 }
 
 /** Resolved package metadata for one `dsh.client` package (cached per name, never expires). */
@@ -756,22 +752,13 @@ export class ClientModuleRegistry extends Service {
     return meta
   }
 
-  /** Capture the bundle and optional-map stats before reading their bytes. */
+  /** Capture the bundle stats before reading its bytes. */
   private captureArtifactBaseline(clientPath: string): ClientArtifactBaseline {
     const bundle = statSync(clientPath)
-    let sourceMap: Stats | undefined
-    try {
-      sourceMap = statSync(`${clientPath}.map`)
-    } catch {
-      // Optional map metadata only seeds HMR; the following map read reports
-      // malformed or inaccessible bytes and a later stat change self-heals.
-    }
     return {
       path: clientPath,
       mtimeMs: bundle.mtimeMs,
       size: bundle.size,
-      mapMtimeMs: sourceMap?.mtimeMs ?? null,
-      mapSize: sourceMap?.size ?? null,
     }
   }
 

packages/client/modules/tests/node-half.client.spec.ts

@@ -378,8 +378,6 @@ describe('client bundle activation', () => {
       path: firstPath,
       mtimeMs: firstStat.mtimeMs,
       size: firstStat.size,
-      mapMtimeMs: null,
-      mapSize: null,
     })
     expect(service.artifactBaseline('@fixture/unknown')).toBeUndefined()
   })

packages/extensions/tool-cordis/src/api-catalog.ts

@@ -3434,7 +3434,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'ClientArtifactBaseline',
-    declaration: 'export interface ClientArtifactBaseline {\n    readonly path: string;\n    readonly mtimeMs: number;\n    readonly size: number;\n    readonly mapMtimeMs: number | null;\n    readonly mapSize: number | null;\n}',
+    declaration: 'export interface ClientArtifactBaseline {\n    readonly path: string;\n    readonly mtimeMs: number;\n    readonly size: number;\n}',
   },
   {
     name: 'CodeBindingErrorClass',