Fail the build on a bare catch, and say why each one is empty

.github/scripts/check-empty-catch.mjs

@@ -0,0 +1,81 @@
+// A catch clause whose block holds neither a statement nor a comment swallows the
+// error with nothing on record saying why that is safe (#205). The comment is the
+// reason; a block with statements handles the error and needs none. Only the
+// statement form is checked: the `void p.catch(() => {})` promise form is a separate
+// fire-and-forget idiom, and test helpers may retry through a bare catch.
+// Usage: node .github/scripts/check-empty-catch.mjs   (exit 1 lists every violation)
+import { readdirSync, readFileSync } from 'node:fs'
+import { join } from 'node:path'
+
+const CATCH = /(?<![\w$.])catch\s*(?:\([^)]*\))?\s*\{/g
+
+// The block after `{`, ending at the brace that closes it. Braces inside strings can
+// only end the walk early, and a truncated block still shows its leading statements,
+// so the walk never invents a violation that is not there.
+const blockOf = (source, open) => {
+  let depth = 0
+  for (let at = open; at < source.length; at += 1) {
+    if (source[at] === '{') depth += 1
+    if (source[at] === '}') {
+      depth -= 1
+      if (depth === 0) return source.slice(open + 1, at)
+    }
+  }
+  return source.slice(open + 1)
+}
+
+// What remains of the block once comments are gone; `comment` says whether any was.
+const stripComments = (block) => {
+  let comment = false
+  const code = block.replace(/\/\/[^\n]*|\/\*[\s\S]*?\*\//g, (found) => {
+    comment = true
+    return ''
+  })
+  return { code, comment }
+}
+
+export function scanSource(name, source) {
+  const found = []
+  for (const match of source.matchAll(CATCH)) {
+    const open = match.index + match[0].length - 1
+    const { code, comment } = stripComments(blockOf(source, open))
+    if (code.trim() === '' && !comment) {
+      const line = source.slice(0, match.index).split('\n').length
+      found.push(`${name}:${line}`)
+    }
+  }
+  return found
+}
+
+const under = (dir, names) => {
+  const out = []
+  for (const entry of readdirSync(dir, { withFileTypes: true })) {
+    if (entry.name === 'node_modules' || entry.name === 'dist' || entry.name === 'dev' || entry.name === 'test') continue
+    const path = join(dir, entry.name)
+    if (entry.isDirectory()) out.push(...under(path, names))
+    else if (entry.isFile() && entry.name.endsWith('.js')) out.push(path)
+  }
+  return out
+}
+
+export function collectTargets(root) {
+  const files = [join(root, 'core/index.js'), join(root, 'core/web-search.js'), ...under(join(root, 'core/src'))]
+  for (const plugin of readdirSync(join(root, 'plugins'), { withFileTypes: true })) {
+    if (!plugin.isDirectory()) continue
+    const dir = join(root, 'plugins', plugin.name)
+    for (const name of ['index.js', 'client.js']) files.push(join(dir, name))
+    files.push(...under(join(dir, 'src')))
+  }
+  return files
+}
+
+export function scanTree(root) {
+  return collectTargets(root).flatMap((path) => scanSource(path, readFileSync(path, 'utf8')))
+}
+
+if (process.argv[1] === import.meta.filename) {
+  const root = join(import.meta.dirname, '..', '..')
+  const violations = scanTree(root)
+  for (const where of violations) console.log(`${where}: empty catch: the error is swallowed with no reason on record`)
+  if (violations.length > 0) process.exit(1)
+}

.github/scripts/check-empty-catch.test.mjs

@@ -0,0 +1,27 @@
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import { join } from 'node:path'
+import { scanSource, scanTree } from './check-empty-catch.mjs'
+
+test('scanSource: a catch block with no statement and no comment is a violation', () => {
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch {}\n'), ['a.js:1'])
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch (e) {}\n'), ['a.js:1'])
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch ({ message }) {}\n'), ['a.js:1'])
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch ({}) {}\n'), ['a.js:1'])
+  assert.deepEqual(scanSource('a.js', 'try {\n  x()\n} catch {\n\n}\n'), ['a.js:3'])
+})
+
+test('scanSource: a comment in the block is the reason; statements handle the error', () => {
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch { /* racing unlink */ }\n'), [])
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch (e) { return }\n'), [])
+  assert.deepEqual(scanSource('a.js', 'try { x() } catch {\n  // retries on the next poll\n}\n'), [])
+})
+
+test('scanSource: the promise form, plain blocks and other identifiers are out of scope', () => {
+  assert.deepEqual(scanSource('a.js', 'void save().catch(() => {})\n'), [])
+  assert.deepEqual(scanSource('a.js', 'for (;;) {}\nconst o = { catch: 1 }\n'), [])
+})
+
+test('the shipped sources carry no bare catch', () => {
+  assert.deepEqual(scanTree(join(import.meta.dirname, '..', '..')), [])
+})

core/index.js

@@ -68,7 +68,7 @@ export function provideFlyBot(ctx, flybot) {
     try {
       ctx.set('flybot', flybot)
       return
-    } catch {}
+    } catch { /* the key is refused: fall through to the plain property */ }
   }
   ctx.flybot = flybot
 }

core/src/client/flybot-registry.js

@@ -96,7 +96,7 @@ export function createClientApi({ call: callFn, registry: slots = registry, ever
         const { seq: _seq, ...event } = change
         for (const fn of [...listeners]) fn(event)
       }
-    } catch {}
+    } catch { /* a failed poll leaves the fields as they are; the next one catches up */ }
   }
   return {
     bots: () => callFn('bots'),

core/src/client/index.js

@@ -47,7 +47,7 @@ export function apply(ctx) {
     if (typeof ctx.provide === 'function') ctx.provide('flybot', flybot)
     else if (typeof ctx.reflect?.provide === 'function') ctx.reflect.provide('flybot', flybot)
     else if (typeof ctx.set === 'function') ctx.set('flybot', flybot)
-  } catch {}
+  } catch { /* every provide form refused: __flybot__.api above still serves plugins */ }
   ctx.effect(() => installLocale(ctx.get('locale')), 'ds-bot: interface copy')
   ctx.effect(() => installBrandChrome(), 'ds-bot: brand chrome')
   const roster = createSource(EMPTY_ROSTER)

core/src/host/diagnostics.js

@@ -105,9 +105,9 @@ const dshVersion = () => {
       try {
         const manifest = JSON.parse(readFileSync(join(dir, 'package.json'), 'utf8'))
         if (manifest.name === '@deepseek-ai/dsh-llm') return manifest.version
-      } catch {}
+      } catch { /* no readable manifest at this depth: keep walking up */ }
     }
-  } catch {}
+  } catch { /* the package does not resolve here: no version to report */ }
   return undefined
 }
 

core/src/host/home-lock.js

@@ -50,7 +50,7 @@ export function homeLock(path, { staleMs = 60_000, beatMs = 15_000, host = hostn
       return
     }
     const time = new Date(now())
-    try { utimesSync(path, time, time) } catch {}
+    try { utimesSync(path, time, time) } catch { /* best effort: a stale mtime only lets a live check retake it */ }
   }
   const stop = () => {
     if (timer !== undefined) clearInterval(timer)
@@ -80,7 +80,7 @@ export function homeLock(path, { staleMs = 60_000, beatMs = 15_000, host = hostn
           ? current?.token === holder.token
           : JSON.stringify(current) === JSON.stringify(holder)
       if (unchanged) {
-        try { unlinkSync(path) } catch {}
+        try { unlinkSync(path) } catch { /* another claimer removed it first */ }
       }
     }
     return read() ?? {}
@@ -89,7 +89,7 @@ export function homeLock(path, { staleMs = 60_000, beatMs = 15_000, host = hostn
   function release() {
     stop()
     if (owns()) {
-      try { unlinkSync(path) } catch {}
+      try { unlinkSync(path) } catch { /* already gone, or taken over */ }
     }
   }
 

core/src/host/hooks.js

@@ -816,7 +816,7 @@ export function install(rt) {
         // A message the user addressed to a friend's Bot is that Bot's to answer; its
         // reply comes back into this chat. The local Bot does not answer it itself.
         if (!results.some(result => result.action !== 'deny') || rt.roomOf(id)) return
-        try { (await rt.resolveAgent(id)).cancel({ kind: 'user' }) } catch {}
+        try { (await rt.resolveAgent(id)).cancel({ kind: 'user' }) } catch { /* ended or already gone: nothing to cancel */ }
       })
       .catch(error => warn('flybot: user mention failed: %s', error))
   })

docs/code-standards.md

@@ -24,6 +24,11 @@ When you report status on a change:
 - If review or a test finds one escape path, fix the shared helper and cover sibling markers (`untrusted-message`, `untrusted-file`, trusted headers).
 - Same-class reds tighten LESSONS / this file; do not paper over with a special case.
 
+## Silent catches
+
+- A `catch` that swallows the error says why in a comment inside the block (or handles it); `check-empty-catch` in `.github/scripts/` fails the build on a bare one (#205).
+- The `void p.catch(() => {})` promise form is a separate fire-and-forget idiom and test-helper retries stay out of the gate's scope.
+
 ## Security: fences and remote strings
 
 - Untrusted bodies stay inside fences; closing markers must not reconstitute after a single strip.

patches/ds-bot/0001-core-fixes.patch

@@ -380,6 +380,18 @@ diff --git a/src/host/diagnostics.js b/src/host/diagnostics.js
      row('DSH', facts.dshVersion),
      row('Surface', client.surface),
      row('OS', facts.os),
+@@ -105,9 +105,9 @@ const dshVersion = () => {
+       try {
+         const manifest = JSON.parse(readFileSync(join(dir, 'package.json'), 'utf8'))
+         if (manifest.name === '@deepseek-ai/dsh-llm') return manifest.version
+-      } catch {}
++      } catch { /* no readable manifest at this depth: keep walking up */ }
+     }
+-  } catch {}
++  } catch { /* the package does not resolve here: no version to report */ }
+   return undefined
+ }
+
 @@ -167,7 +167,9 @@ export function install(rt) {
      const error = args.find(arg => arg instanceof Error)
      const line = clean(format(template, ...args.map(arg => (arg instanceof Error ? errorText(arg) : arg))))

patches/ds-bot/0002-flybot-api-host.patch

@@ -51,12 +51,42 @@ diff --git a/index.js b/index.js
 +    try {
 +      ctx.set('flybot', flybot)
 +      return
-+    } catch {}
++    } catch { /* the key is refused: fall through to the plain property */ }
 +  }
 +  ctx.flybot = flybot
  }
 
  export function createRuntime(ctx, config = {}) {
+diff --git a/src/host/home-lock.js b/src/host/home-lock.js
+--- a/src/host/home-lock.js
++++ b/src/host/home-lock.js
+@@ -50,7 +50,7 @@ export function homeLock(path, { staleMs = 60_000, beatMs = 15_000, host = hostn
+       return
+     }
+     const time = new Date(now())
+-    try { utimesSync(path, time, time) } catch {}
++    try { utimesSync(path, time, time) } catch { /* best effort: a stale mtime only lets a live check retake it */ }
+   }
+   const stop = () => {
+     if (timer !== undefined) clearInterval(timer)
+@@ -80,7 +80,7 @@ export function homeLock(path, { staleMs = 60_000, beatMs = 15_000, host = hostn
+           ? current?.token === holder.token
+           : JSON.stringify(current) === JSON.stringify(holder)
+       if (unchanged) {
+-        try { unlinkSync(path) } catch {}
++        try { unlinkSync(path) } catch { /* another claimer removed it first */ }
+       }
+     }
+     return read() ?? {}
+@@ -89,7 +89,7 @@ export function homeLock(path, { staleMs = 60_000, beatMs = 15_000, host = hostn
+   function release() {
+     stop()
+     if (owns()) {
+-      try { unlinkSync(path) } catch {}
++      try { unlinkSync(path) } catch { /* already gone, or taken over */ }
+     }
+   }
+
 diff --git a/src/host/roster.js b/src/host/roster.js
 --- a/src/host/roster.js
 +++ b/src/host/roster.js

patches/ds-bot/0003-flybot-api-client.patch

@@ -490,7 +490,7 @@ diff --git a/src/client/index.js b/src/client/index.js
 +    if (typeof ctx.provide === 'function') ctx.provide('flybot', flybot)
 +    else if (typeof ctx.reflect?.provide === 'function') ctx.reflect.provide('flybot', flybot)
 +    else if (typeof ctx.set === 'function') ctx.set('flybot', flybot)
-+  } catch {}
++  } catch { /* every provide form refused: __flybot__.api above still serves plugins */ }
    ctx.effect(() => installLocale(ctx.get('locale')), 'ds-bot: interface copy')
 +  ctx.effect(() => installBrandChrome(), 'ds-bot: brand chrome')
    const roster = createSource(EMPTY_ROSTER)

patches/ds-bot/files/src/client/flybot-registry.js

@@ -96,7 +96,7 @@ export function createClientApi({ call: callFn, registry: slots = registry, ever
         const { seq: _seq, ...event } = change
         for (const fn of [...listeners]) fn(event)
       }
-    } catch {}
+    } catch { /* a failed poll leaves the fields as they are; the next one catches up */ }
   }
   return {
     bots: () => callFn('bots'),

patches/ds-bot/files/src/host/hooks.js

@@ -816,7 +816,7 @@ export function install(rt) {
         // A message the user addressed to a friend's Bot is that Bot's to answer; its
         // reply comes back into this chat. The local Bot does not answer it itself.
         if (!results.some(result => result.action !== 'deny') || rt.roomOf(id)) return
-        try { (await rt.resolveAgent(id)).cancel({ kind: 'user' }) } catch {}
+        try { (await rt.resolveAgent(id)).cancel({ kind: 'user' }) } catch { /* ended or already gone: nothing to cancel */ }
       })
       .catch(error => warn('flybot: user mention failed: %s', error))
   })

patches/ds-bot/topics.json

@@ -21,6 +21,7 @@
     "src/host/store.js",
     "src/host/roster.js",
     "src/host/tools.js",
+    "src/host/home-lock.js",
     "test/fake-ctx.js"
   ],
   "0003-flybot-api-client": [

plugins/social/client.js

@@ -897,7 +897,7 @@
           await clip?.writeText?.(handle)
           setCopied(true)
           setTimeout(() => setCopied(false), 1500)
-        } catch {}
+        } catch { /* clipboard denied: skip the Copied feedback */ }
       }
       return h('div', { className: 'fs-me', 'data-flybot': 'my-handle-menu' },
         h('span', { className: 'fs-me-handle', title: 'Your Bot Social handle' }, handle),
@@ -1354,7 +1354,7 @@
         status = { at: Date.now(), value }
         if (changed) for (const fn of [...statusListeners]) { try { fn() } catch (error) { console.error('flybot-social: status listener failed', error) } }
         return value
       }).finally(() => { statusTask = undefined })
       return statusTask
     }
     // Fires when what canInvite answers may have changed (first status, connect/disconnect, Bots added).

plugins/social/index.js

@@ -32,9 +32,9 @@ export function apply(ctx, config = {}) {
     .catch((error) => {
       const reason = startFailureReason(error)
       console.warn('flybot-social: start failed:', reason)
-      try { ctx.logger?.warn?.('flybot-social: start failed: %s', reason) } catch {}
+      try { ctx.logger?.warn?.('flybot-social: start failed: %s', reason) } catch { /* the logger failed while reporting the failure */ }
       // Host diagnostics (Settings → Feedback). Optional on older cores without flybot.warn.
-      try { ctx.flybot?.warn?.('flybot-social: start failed: %s', error) } catch {}
+      try { ctx.flybot?.warn?.('flybot-social: start failed: %s', error) } catch { /* the optional channel itself failed */ }
       if (!stopped) unavailableOff = registerUnavailable(ctx.flybot, reason)
     })
   ctx.effect(() => () => {

plugins/social/src/mcp-client.js

@@ -41,7 +41,7 @@
   const lib = parsed.protocol === 'http:' ? http : https
   const agent = init.agent ?? agentFor(url)
   const method = String(init.method ?? 'GET').toUpperCase()
   const headers = { ...(init.headers ?? {}) }
   const signal = init.signal
   return new Promise((resolve, reject) => {
     const req = lib.request(parsed, { method, headers, agent }, (res) => {
@@ -76,7 +76,7 @@
   const list = [...items]
   if (list.length === 0) return []
   const cap = Math.max(1, Math.min(limit || GRANT_CONCURRENCY, list.length))
   const out = new Array(list.length)
   let next = 0
   async function worker() {
     for (;;) {
@@ -145,7 +145,7 @@
   if (/text\/event-stream/i.test(type) || /^(event|data|id):/m.test(text.trimStart().slice(0, 6))) {
     const data = text.split(/\r?\n/).filter(line => line.startsWith('data:')).map(line => line.slice(5).trim()).filter(Boolean)
     for (const line of data.reverse()) {
-      try { const value = JSON.parse(line); if (value && (value.result !== undefined || value.error !== undefined)) return value } catch {}
+      try { const value = JSON.parse(line); if (value && (value.result !== undefined || value.error !== undefined)) return value } catch { /* not the JSON-RPC answer: try the next data line */ }
     }
     throw new BotSocialError('Bot Social: the event stream had no answer', 'sse')
   }

plugins/social/src/social.js

@@ -81,9 +81,9 @@
 const TEXTUAL = new Set(['text/plain', 'text/markdown', 'text/csv', 'text/tab-separated-values', 'application/json'])
 const sizeLabel = n => (n < 1024 ? `${n} B` : n < 1048576 ? `${(n / 1024).toFixed(1)} KB` : `${(n / 1048576).toFixed(1)} MB`)
 // Remote strings that reach model-visible text: one line, no brackets or markup, capped.
 export const cleanText = (value, fallback = '') => String(value ?? '').replace(/[\u0000-\u001f\u007f-\u009f\u2028\u2029]/g, ' ').replace(/[[\]"<>`]/g, '').replace(/\s+/g, ' ').trim().slice(0, 60) || fallback
 // Owner-only draft body: keep punctuation the friend will see; strip controls and cap.
 export const draftText = (value) => String(value ?? '').replace(/[\u0000-\u001f\u007f-\u009f\u2028\u2029]/g, ' ').replace(/\s+/g, ' ').trim().slice(0, 800)
 // Owner cards never show the FLYBOT-FACE-HUMAN wire envelope (#159).
 export function approvalDraftText(value) {
   const raw = draftText(value)
@@ -136,7 +136,7 @@
 }
 const SEEN_KEPT = 1000
 const CREDENTIAL_NAME = /(^id_(rsa|dsa|ecdsa|ed25519)|\.(pem|key|p12|pfx|kdbx|keychain)$|credential|secret|token|password|passwd|^flybot-social.*\.json$|^\.?env$|^\.netrc$|^known_hosts$|^authorized_keys$)/i
 const safeName = name => String(name ?? 'file').replace(/[\u0000-\u001f\u007f/\\:]/g, '_').replace(/^\.+/, '_').slice(0, 120) || 'file'
 // The text Copy puts on the clipboard for a per-Bot invite: what to do with the link, for a
 // person in FlyBot or for their Grok bot.
 export function inviteText({ handle, name, home, url, expiresAt }) {
@@ -294,7 +294,7 @@
 export const writeCredentials = (path, value) => {
   mkdirSync(dirname(path), { recursive: true })
   writeFileSync(path, JSON.stringify(value, null, 2), { mode: 0o600 })
-  try { chmodSync(path, 0o600) } catch {}
+  try { chmodSync(path, 0o600) } catch { /* file systems that ignore the write mode */ }
 }
 
 export function createSocial(service, config = {}, { client: given, api: givenApi, home: givenHome, now = Date.now, setInterval: every = globalThis.setInterval, clearInterval: clear = globalThis.clearInterval, faceApi: givenFace } = {}) {
@@ -389,7 +389,7 @@
     if (CREDENTIAL_NAME.test(basename(file))) return 'it looks like a credential'
     for (const dir of privateDirs()) {
       let real = dir
-      try { real = realpathSync(dir) } catch {}
+      try { real = realpathSync(dir) } catch { /* not a symlink or gone: compare the path as it is */ }
       if (file === real || file.startsWith(real + sep)) return 'it is a private FlyBot file'
     }
     if (!(extname(file).toLowerCase() in MIME)) return `only ${Object.keys(MIME).join(' ')} files`
@@ -575,7 +575,7 @@
       if (result?.unavailable) return
     } catch (error) {
       if (/invalid_avatar|invalid_color|invalid_request/i.test(`${error?.code ?? ''} ${error?.message ?? ''}`)) {
         settings.lookSynced = { ...(settings.lookSynced ?? {}), [bot.id]: fingerprint }
         saveSettings()
         return
       }
@@ -1097,7 +1097,7 @@
         try {
           const message = await client.callTool('send_message', { conversation_id: bot.conversationId, text: msg.text })
           return { exchangeId: message?.message_id ?? msg.exchangeId }
-        } catch {}
+        } catch { /* the old conversation is gone: start a fresh one below */ }
       }
       const started = await client.callTool('start_conversation', { friend: bot.handle, text: msg.text, ...(config.botId ? { bot_id: config.botId } : {}) })
       // Kept, so a file sent right after goes into this conversation.