feat: await support in browse js/eval + contributor mode v2 (#104)

* feat: support await in $B js and eval commands

Auto-wrap await expressions in async IIFE context so
$B js "await fetch(...)" works without SyntaxError.

- hasAwait() strips comments before detection
- js: expression wrapping (async()=>(expr))()
- eval: smart wrapping — single-line=expression, multi-line=block
- 6 new unit tests covering async, false-positive, and return semantics

* feat: redesign contributor mode — periodic reflection with 0-10 rating

Replace passive "report when things break" with active reflection:
- Rate gstack experience 0-10 at workflow step boundaries
- Historical calibration example (await bug) anchors the reporting bar
- "What would make this a 10" field focuses on actionable improvements
- Removed category lists in favor of judgment-based assessment

* test: add deterministic contributor mode preamble validation

40 new skill-validation tests (4 checks × 10 skills) verify:
- 0-10 rating scale present
- Calibration example present
- "What would make this a 10" field present
- Periodic reflection (not per-command)

Update existing E2E contributor eval for new report format.

* chore: bump version and changelog (v0.4.2)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: improve contributor mode + qa-quick E2E reliability

Contributor mode:
- Add "do not truncate" directive to template — agent was stopping
  after "My rating" without completing Steps/Raw output/What would
  make this a 10 sections
- Restore assertions for Steps to reproduce and Date footer

QA quick:
- Make test server URL prominent: top of prompt, explicit "already
  running" and "do NOT discover ports" instructions
- Bump session timeout 180s→240s and test timeout 240s→300s
- Set B= at top of prompt (was buried in prose)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: use flexible assertions for contributor mode E2E

Agent writes thorough reports with creative section names
("Repro Steps" vs "Steps to reproduce"). Match intent not formatting:
- /repro|steps to reproduce/ for reproduction steps
- /date.*2026/ for date footer presence

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: add E2E eval failure blame protocol

"Not related to our changes" is an extraordinary claim that requires
extraordinary proof. When evals fail during /ship:

1. Run the same eval on main — prove it fails there too
2. If it passes on main, it IS your change — trace the blame
3. If you can't verify, say "unverified" not "pre-existing"

Added to CLAUDE.md and as a comment in skill-e2e.test.ts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: update CONTRIBUTING.md and BROWSER.md for v0.4.2

CONTRIBUTING.md: update contributor mode description — now describes
periodic 0-10 reflection loop instead of passive friction detection.

BROWSER.md: add js/eval async documentation — await expressions are
auto-wrapped in async context, single-line eval returns values directly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: restore v0.4.2 changelog entries lost during cherry-pick conflict

The base branch detection entries from main were dropped when resolving
the CHANGELOG conflict — should have merged both sets, not replaced.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

browse/SKILL.md

@@ -44,12 +44,15 @@ Per-skill instructions may add additional formatting rules on top of this baseli
 
 ## Contributor Mode
 
-If `_CONTRIB` is `true`: you are in **contributor mode**. When you hit friction with **gstack itself** (not the user's app), file a field report. Think: "hey, I was trying to do X with gstack and it didn't work / was confusing / was annoying. Here's what happened."
+If `_CONTRIB` is `true`: you are in **contributor mode**. You're a gstack user who also helps make it better.
 
-**gstack issues:** browse command fails/wrong output, snapshot missing elements, skill instructions unclear or misleading, binary crash/hang, unhelpful error message, any rough edge or annoyance — even minor stuff.
-**NOT gstack issues:** user's app bugs, network errors to user's URL, auth failures on user's site.
+**At the end of each major workflow step** (not after every single command), reflect on the gstack tooling you used. Rate your experience 0 to 10. If it wasn't a 10, think about why. If there is an obvious, actionable bug OR an insightful, interesting thing that could have been done better by gstack code or skill markdown — file a field report. Maybe our contributor will help make us better!
 
-**To file:** write `~/.gstack/contributor-logs/{slug}.md` with this structure:
+**Calibration — this is the bar:** For example, `$B js "await fetch(...)"` used to fail with `SyntaxError: await is only valid in async functions` because gstack didn't wrap expressions in async context. Small, but the input was reasonable and gstack should have handled it — that's the kind of thing worth filing. Things less consequential than this, ignore.
+
+**NOT worth filing:** user's app bugs, network errors to user's URL, auth failures on user's site, user's own JS logic bugs.
+
+**To file:** write `~/.gstack/contributor-logs/{slug}.md` with **all sections below** (do not truncate — include every section through the Date/Version footer):
 
 ```
 # {Title}
@@ -58,20 +61,23 @@ Hey gstack team — ran into this while using /{skill-name}:
 
 **What I was trying to do:** {what the user/agent was attempting}
 **What happened instead:** {what actually happened}
-**How annoying (1-5):** {1=meh, 3=friction, 5=blocker}
+**My rating:** {0-10} — {one sentence on why it wasn't a 10}
 
 ## Steps to reproduce
 1. {step}
 
 ## Raw output
-(wrap any error messages or unexpected output in a markdown code block)
+```
+{paste the actual error or unexpected output here}
+```
+
+## What would make this a 10
+{one sentence: what gstack should have done differently}
 
 **Date:** {YYYY-MM-DD} | **Version:** {gstack version} | **Skill:** /{skill}
 ```
 
-Then run: `mkdir -p ~/.gstack/contributor-logs && open ~/.gstack/contributor-logs/{slug}.md`
-
-Slug: lowercase, hyphens, max 60 chars (e.g. `browse-snapshot-ref-gap`). Skip if file already exists. Max 3 reports per session. File inline and continue — don't stop the workflow. Tell user: "Filed gstack field report: {title}"
+Slug: lowercase, hyphens, max 60 chars (e.g. `browse-js-no-await`). Skip if file already exists. Max 3 reports per session. File inline and continue — don't stop the workflow. Tell user: "Filed gstack field report: {title}"
 
 # browse: QA Testing & Dogfooding
 

browse/src/read-commands.ts

@@ -11,6 +11,12 @@ import type { Page } from 'playwright';
 import * as fs from 'fs';
 import * as path from 'path';
 
+/** Detect await keyword, ignoring comments. Accepted risk: await in string literals triggers wrapping (harmless). */
+function hasAwait(code: string): boolean {
+  const stripped = code.replace(/\/\/.*$/gm, '').replace(/\/\*[\s\S]*?\*\//g, '');
+  return /\bawait\b/.test(stripped);
+}
+
 // Security: Path validation to prevent path traversal attacks
 const SAFE_DIRECTORIES = ['/tmp', process.cwd()];
 
@@ -118,7 +124,8 @@ export async function handleReadCommand(
     case 'js': {
       const expr = args[0];
       if (!expr) throw new Error('Usage: browse js <expression>');
-      const result = await page.evaluate(expr);
+      const wrapped = hasAwait(expr) ? `(async()=>(${expr}))()` : expr;
+      const result = await page.evaluate(wrapped);
       return typeof result === 'object' ? JSON.stringify(result, null, 2) : String(result ?? '');
     }
 
@@ -128,6 +135,13 @@ export async function handleReadCommand(
       validateReadPath(filePath);
       if (!fs.existsSync(filePath)) throw new Error(`File not found: ${filePath}`);
       const code = fs.readFileSync(filePath, 'utf-8');
+      if (hasAwait(code)) {
+        const trimmed = code.trim();
+        const isSingleExpr = trimmed.split('\n').length === 1;
+        const wrapped = isSingleExpr ? `(async()=>(${trimmed}))()` : `(async()=>{\n${code}\n})()`;
+        const result = await page.evaluate(wrapped);
+        return typeof result === 'object' ? JSON.stringify(result, null, 2) : String(result ?? '');
+      }
       const result = await page.evaluate(code);
       return typeof result === 'object' ? JSON.stringify(result, null, 2) : String(result ?? '');
     }

browse/test/commands.test.ts

@@ -144,6 +144,60 @@ describe('Inspection', () => {
     expect(obj.b).toBe(2);
   });
 
+  test('js supports await expressions', async () => {
+    const result = await handleReadCommand('js', ['await Promise.resolve(42)'], bm);
+    expect(result).toBe('42');
+  });
+
+  test('js does not false-positive on await substring', async () => {
+    const result = await handleReadCommand('js', ['(() => { const awaitable = 5; return awaitable })()'], bm);
+    expect(result).toBe('5');
+  });
+
+  test('eval supports await in single-line file', async () => {
+    const tmp = '/tmp/eval-await-test.js';
+    fs.writeFileSync(tmp, 'await Promise.resolve("hello from eval")');
+    try {
+      const result = await handleReadCommand('eval', [tmp], bm);
+      expect(result).toBe('hello from eval');
+    } finally {
+      fs.unlinkSync(tmp);
+    }
+  });
+
+  test('eval does not wrap when await is only in a comment', async () => {
+    const tmp = '/tmp/eval-comment-test.js';
+    fs.writeFileSync(tmp, '// no need to await this\ndocument.title');
+    try {
+      const result = await handleReadCommand('eval', [tmp], bm);
+      expect(result).toBe('Test Page - Basic');
+    } finally {
+      fs.unlinkSync(tmp);
+    }
+  });
+
+  test('eval multi-line with await and explicit return', async () => {
+    const tmp = '/tmp/eval-multiline-await.js';
+    fs.writeFileSync(tmp, 'const data = await Promise.resolve("multi");\nreturn data;');
+    try {
+      const result = await handleReadCommand('eval', [tmp], bm);
+      expect(result).toBe('multi');
+    } finally {
+      fs.unlinkSync(tmp);
+    }
+  });
+
+  test('eval multi-line with await but no return gives empty string', async () => {
+    const tmp = '/tmp/eval-multiline-no-return.js';
+    fs.writeFileSync(tmp, 'const data = await Promise.resolve("lost");\ndata;');
+    try {
+      const result = await handleReadCommand('eval', [tmp], bm);
+      expect(result).toBe('');
+    } finally {
+      fs.unlinkSync(tmp);
+    }
+  });
+
   test('css returns computed property', async () => {
     const result = await handleReadCommand('css', ['h1', 'color'], bm);
     // Navy color