chore: add a formatter (#21)

* chore: add a formatter, matching the style this repo already writes

singleQuote=true was chosen by counting this repo's own
imports, not by fleet decree. The fleet is genuinely split and the two repos
that already had a .prettierrc disagreed with each other, so there was no
standard to restore. Quote style does not cross repo boundaries; having a
gate does.

Markdown is ignored for now — prettier rewraps prose, which would bury the
real diff.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* style: format with prettier (12 files)

Mechanical. No behaviour change. This SHA is listed in
.git-blame-ignore-revs so `git blame` skips it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* chore: teach git blame to skip the reformat

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: catomean

.git-blame-ignore-revs

@@ -0,0 +1,2 @@
+# Bulk reformats. `git config blame.ignoreRevsFile .git-blame-ignore-revs`
+6e12c84d059bb4f261a25a27a57c44e58f658bca  # prettier, 12 files

.github/dependabot.yml

@@ -11,7 +11,7 @@
 version: 2
 updates:
   - package-ecosystem: npm
-    directory: "/"
+    directory: '/'
     schedule:
       interval: weekly
     open-pull-requests-limit: 5
@@ -20,7 +20,7 @@ updates:
         update-types: [minor, patch]
 
   - package-ecosystem: github-actions
-    directory: "/"
+    directory: '/'
     schedule:
       interval: weekly
     open-pull-requests-limit: 3

.prettierignore

@@ -0,0 +1,31 @@
+# Build output and vendored trees — formatting these is noise.
+node_modules
+.next
+dist
+build
+out
+coverage
+.turbo
+.vercel
+*.min.js
+*.min.css
+
+# Generated during a build, so it is absent locally and present in CI — which
+# makes a clean local --check no evidence at all. Contentlayer's output also
+# uses import assertions, which prettier's parser rejects outright.
+.contentlayer
+.astro
+.svelte-kit
+storybook-static
+test-results
+playwright-report
+
+# Lockfiles are generated; prettier would rewrite them wholesale.
+package-lock.json
+pnpm-lock.yaml
+yarn.lock
+
+# Markdown is deliberately out of scope for now. Prettier rewraps prose, which
+# is where it is most opinionated and least useful, and it would bury the real
+# diff. Remove this line when you want docs formatted too.
+*.md

.prettierrc

@@ -0,0 +1,9 @@
+{
+  "semi": true,
+  "singleQuote": true,
+  "printWidth": 100,
+  "tabWidth": 2,
+  "trailingComma": "all",
+  "arrowParens": "always",
+  "endOfLine": "lf"
+}

eslint.config.mjs

@@ -2,9 +2,9 @@
 // library code, and a bespoke rule set would be a second opinion to maintain
 // for no benefit. The floor is "lint runs and can fail", not "lint encodes
 // taste".
-import js from '@eslint/js'
-import globals from 'globals'
-import tseslint from 'typescript-eslint'
+import js from '@eslint/js';
+import globals from 'globals';
+import tseslint from 'typescript-eslint';
 
 export default tseslint.config(
   {
@@ -22,4 +22,4 @@ export default tseslint.config(
     files: ['test/**/*.js', 'scripts/**/*.{js,mjs}'],
     languageOptions: { globals: { ...globals.node, ...globals.nodeBuiltin } },
   },
-)
+);

package-lock.json

@@ -44,14 +44,17 @@
     "lint": "eslint .",
     "typecheck": "tsc -p tsconfig.json --noEmit",
     "test": "node --test test/*.test.js",
-    "verify": "npm run lint && npm run typecheck && npm run build && npm test",
-    "prepare": "npm run build"
+    "verify": "npm run format:check && npm run lint && npm run typecheck && npm run build && npm test",
+    "prepare": "npm run build",
+    "format": "prettier --write .",
+    "format:check": "prettier --check ."
   },
   "devDependencies": {
     "@eslint/js": "^9.39.5",
     "@types/node": "^22.10.2",
     "eslint": "^9.39.5",
     "globals": "^15.15.0",
+    "prettier": "3.9.6",
     "typescript": "^5.8.2",
     "typescript-eslint": "^8.67.0"
   }

package.json

@@ -67,11 +67,11 @@ export function whenMentioned(aliases: readonly string[]): RespondPolicy {
   // addressed to it.
   const patterns = aliases
     .filter(Boolean)
-    .map(a => new RegExp(`(^|\\W)${a.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}(\\W|$)`, 'i'));
+    .map((a) => new RegExp(`(^|\\W)${a.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}(\\W|$)`, 'i'));
   return ({ visible, self }) => {
     const last = visible[visible.length - 1];
     if (!last || last.authorId === self.actorId) return false;
-    return patterns.some(re => re.test(last.body));
+    return patterns.some((re) => re.test(last.body));
   };
 }
 
@@ -84,7 +84,7 @@ export function whenMentioned(aliases: readonly string[]): RespondPolicy {
  * clinical thread unusable the moment an assistant joined.
  */
 export function defaultRespondPolicy(ctx: AiTurnContext): boolean {
-  const active = ctx.thread.participants.filter(p => !p.leftAt);
+  const active = ctx.thread.participants.filter((p) => !p.leftAt);
   if (active.length <= 2) return afterEveryMessage(ctx);
   return whenMentioned([ctx.self.role ?? 'assistant', 'ai'])(ctx);
 }
@@ -98,12 +98,9 @@ function trailingSelfMessages(visible: readonly Message[], actorId: string): num
   return n;
 }
 
-function renderTranscript(
-  ctx: AiTurnContext,
-  label: (p: Participant) => string
-): string {
+function renderTranscript(ctx: AiTurnContext, label: (p: Participant) => string): string {
   return ctx.visible
-    .map(m => {
+    .map((m) => {
       const author = findParticipant(ctx.thread, m.authorId);
       const who = author ? label(author) : 'unknown';
       return `${who}: ${m.body}`;
@@ -124,7 +121,7 @@ function renderTranscript(
 export async function runAiTurn(
   thread: Thread,
   allMessages: readonly Message[],
-  config: AiParticipantConfig
+  config: AiParticipantConfig,
 ): Promise<AiTurnResult> {
   const self = findParticipant(thread, config.actorId);
   if (!self) return { status: 'skipped', reason: 'not a participant in this thread' };

src/ai.ts

@@ -22,15 +22,5 @@ export { unreadCount, unreadMessages, unreadThreadCount } from './unread.js';
 
 export { compareMessages, isPending, mergeMessages } from './merge.js';
 
-export {
-  afterEveryMessage,
-  defaultRespondPolicy,
-  runAiTurn,
-  whenMentioned,
-} from './ai.js';
-export type {
-  AiParticipantConfig,
-  AiTurnContext,
-  AiTurnResult,
-  RespondPolicy,
-} from './ai.js';
+export { afterEveryMessage, defaultRespondPolicy, runAiTurn, whenMentioned } from './ai.js';
+export type { AiParticipantConfig, AiTurnContext, AiTurnResult, RespondPolicy } from './ai.js';

src/index.ts

@@ -26,7 +26,7 @@ export function compareMessages(a: Message, b: Message): number {
  */
 export function mergeMessages(
   existing: readonly Message[],
-  incoming: readonly Message[]
+  incoming: readonly Message[],
 ): Message[] {
   const byId = new Map<string, Message>();
   const idByClientId = new Map<string, string>();