fix(wsl): watch the whole worktree so nested external edits reach open editors

The WSL in-distro poll scan was capped at `-maxdepth 2`, so external edits to any file nested deeper never produced an `fs:changed` event. An open editor tab kept its in-memory content until it was closed and reopened — the reported workaround.

Remove the depth cap so the scan matches the recursive watcher behaviour on native platforms.

Fixes #7792

Co-authored-by: Orca <help@stably.ai>

src/main/ipc/filesystem-watcher-wsl.test.ts

@@ -174,6 +174,36 @@ describe('createWslWatcher', () => {
     ])
   })
 
+  it('emits update events for files nested more than two levels deep', async () => {
+    const scheduleBatchFlush = vi.fn()
+    const { child, promise } = startWatcher(makeDeps(scheduleBatchFlush))
+
+    child.stdout.write(
+      snapshotFrame([
+        ['d', '1.0', '/home/me/repo/docs'],
+        ['d', '1.0', '/home/me/repo/docs/api'],
+        ['f', '1.0', '/home/me/repo/docs/api/reference.md']
+      ])
+    )
+    const root = await promise
+    child.stdout.write(
+      snapshotFrame([
+        ['d', '1.0', '/home/me/repo/docs'],
+        ['d', '1.0', '/home/me/repo/docs/api'],
+        ['f', '2.0', '/home/me/repo/docs/api/reference.md'],
+        ['f', '1.0', '/home/me/repo/src/main/deep/new.md']
+      ])
+    )
+
+    expect(root.batch.events).toEqual([
+      {
+        type: 'update',
+        path: '\\\\wsl.localhost\\Ubuntu\\home\\me\\repo\\docs\\api\\reference.md'
+      },
+      { type: 'create', path: '\\\\wsl.localhost\\Ubuntu\\home\\me\\repo\\src\\main\\deep\\new.md' }
+    ])
+  })
+
   it('turns watcher exit into an overflow refresh without retaining UNC paths', async () => {
     const scheduleBatchFlush = vi.fn()
     const deps = makeDeps(scheduleBatchFlush)

src/main/ipc/filesystem-watcher-wsl.ts

@@ -13,6 +13,7 @@ import { queueWatcherEvents } from './filesystem-watcher-event-batch'
 import { parseWslUncPath } from '../../shared/wsl-paths'
 import { createWslWatcherProcessExit, createWslWatcherStartup } from './wsl-watcher-process-exit'
 import { reserveWatcherChild, WatcherChildCapacityError } from './parcel-watcher-child-registry'
+import { buildSnapshotScript } from './wsl-snapshot-poll-script'
 
 export type WatcherSubscription = {
   unsubscribe(): Promise<void>
@@ -40,7 +41,6 @@ export type WslWatcherDeps = {
   watchedRoots: Map<string, WatchedRoot>
 }
 
-const POLL_INTERVAL_SECONDS = 2
 const STARTUP_TIMEOUT_MS = 10_000
 const [SNAPSHOT_START, SNAPSHOT_END] = ['\x1e', '\x1f']
 const MAX_STREAM_BUFFER_CHARS = 10 * 1024 * 1024
@@ -57,37 +57,6 @@ function toWslUncPath(linuxPath: string, distro: string): string {
   return `\\\\wsl.localhost\\${distro}${linuxPath.replace(/\//g, '\\')}`
 }
 
-function quoteSafeFindName(name: string): string {
-  if (!/^[A-Za-z0-9_.-]+$/.test(name)) {
-    throw new Error(`Unsupported WSL watcher ignore name: ${name}`)
-  }
-  return `'${name}'`
-}
-
-function buildPruneExpression(ignoreDirs: readonly string[]): string {
-  if (ignoreDirs.length === 0) {
-    return ''
-  }
-  const names = ignoreDirs.map((name) => `-name ${quoteSafeFindName(name)}`).join(' -o ')
-  return `\\( -type d \\( ${names} \\) -prune \\) -o`
-}
-
-function buildSnapshotScript(ignoreDirs: readonly string[]): string {
-  const prune = buildPruneExpression(ignoreDirs)
-  return [
-    'set -efu',
-    'root=$1',
-    'while :; do',
-    "  printf '\\036'",
-    '  if [ -d "$root" ]; then',
-    `    find "$root" -mindepth 1 -maxdepth 2 ${prune} -printf '%y\\t%T@\\t%p\\0' 2>/dev/null || true`,
-    '  fi',
-    "  printf '\\037'",
-    `  sleep ${POLL_INTERVAL_SECONDS} || exit 0`,
-    'done'
-  ].join('\n')
-}
-
 function parseSnapshotFrame(frame: string, distro: string): WslSnapshot {
   const snapshot: WslSnapshot = new Map()
   for (const rawEntry of frame.split('\0')) {

src/main/ipc/wsl-snapshot-poll-script.test.ts

@@ -0,0 +1,42 @@
+import { describe, expect, it } from 'vitest'
+
+import { buildSnapshotScript } from './wsl-snapshot-poll-script'
+
+function scanLine(script: string): string {
+  const line = script.split('\n').find((entry) => entry.includes('find "$root"'))
+  expect(line).toBeDefined()
+  return line as string
+}
+
+describe('buildSnapshotScript', () => {
+  it('scans the whole worktree so files nested below two levels are seen', () => {
+    const line = scanLine(buildSnapshotScript(['node_modules', '.git']))
+
+    expect(line).toContain('-mindepth 1')
+    expect(line).not.toContain('-maxdepth')
+  })
+
+  it('prunes ignored directories at every depth', () => {
+    const line = scanLine(buildSnapshotScript(['node_modules', '.git']))
+
+    expect(line).toContain("\\( -type d \\( -name 'node_modules' -o -name '.git' \\) -prune \\) -o")
+  })
+
+  it('backs the poll interval off on large trees instead of capping depth', () => {
+    const script = buildSnapshotScript(['node_modules'])
+
+    expect(script).toContain('size=$(wc -c < "$snapshot" 2>/dev/null || echo 0)')
+    expect(script).toContain('interval=10')
+    expect(script).toContain('sleep "$interval" || exit 0')
+  })
+
+  it('fails loudly on distros whose find lacks GNU -printf', () => {
+    expect(buildSnapshotScript([])).toContain('orca-watcher-unsupported-find')
+  })
+
+  it('rejects ignore names that would break out of the find expression', () => {
+    expect(() => buildSnapshotScript(["a' -o -delete '"])).toThrow(
+      'Unsupported WSL watcher ignore name'
+    )
+  })
+})

src/main/ipc/wsl-snapshot-poll-script.ts

@@ -0,0 +1,53 @@
+/**
+ * The `sh` program the WSL watcher pipes into the distro: it polls the worktree
+ * with `find` and streams one framed snapshot per interval.
+ */
+const POLL_INTERVAL_SECONDS = 2
+// Why: a recursive scan of a huge tree costs more per poll than the freshness it
+// buys, so back the in-distro loop off instead of capping depth (which blinds it).
+const SLOW_POLL_INTERVAL_SECONDS = 10
+const LARGE_SNAPSHOT_BYTES = 2_000_000
+
+function quoteSafeFindName(name: string): string {
+  if (!/^[A-Za-z0-9_.-]+$/.test(name)) {
+    throw new Error(`Unsupported WSL watcher ignore name: ${name}`)
+  }
+  return `'${name}'`
+}
+
+function buildPruneExpression(ignoreDirs: readonly string[]): string {
+  if (ignoreDirs.length === 0) {
+    return ''
+  }
+  const names = ignoreDirs.map((name) => `-name ${quoteSafeFindName(name)}`).join(' -o ')
+  return `\\( -type d \\( ${names} \\) -prune \\) -o`
+}
+
+export function buildSnapshotScript(ignoreDirs: readonly string[]): string {
+  const prune = buildPruneExpression(ignoreDirs)
+  return [
+    'set -efu',
+    'root=$1',
+    // Why: BusyBox/Alpine find has no -printf; without this probe every frame is
+    // silently empty and the watcher looks healthy while seeing nothing.
+    "find / -maxdepth 0 -printf '' 2>/dev/null || { printf 'orca-watcher-unsupported-find\\n' >&2; exit 3; }",
+    'snapshot=$(mktemp) || exit 4',
+    `trap 'rm -f "$snapshot"' EXIT`,
+    `trap 'rm -f "$snapshot"; exit 0' INT TERM`,
+    `interval=${POLL_INTERVAL_SECONDS}`,
+    'while :; do',
+    '  : > "$snapshot"',
+    '  if [ -d "$root" ]; then',
+    // The prune expression drops .git/node_modules/etc at every depth, so full
+    // recursion here matches what @parcel/watcher reports on native platforms.
+    `    find "$root" -mindepth 1 ${prune} -printf '%y\\t%T@\\t%p\\0' > "$snapshot" 2>/dev/null || true`,
+    '  fi',
+    "  printf '\\036'",
+    '  cat "$snapshot"',
+    "  printf '\\037'",
+    '  size=$(wc -c < "$snapshot" 2>/dev/null || echo 0)',
+    `  if [ "\${size:-0}" -gt ${LARGE_SNAPSHOT_BYTES} ]; then interval=${SLOW_POLL_INTERVAL_SECONDS}; else interval=${POLL_INTERVAL_SECONDS}; fi`,
+    '  sleep "$interval" || exit 0',
+    'done'
+  ].join('\n')
+}