feat: make assigned pull sheets read-first (#217)

tests/test_my_work.py

@@ -2023,6 +2023,63 @@ process.stdout.write(JSON.stringify({{
     assert output["next"] == "frontend/app.js"
 
 
+def test_pull_sheet_lazy_review_is_single_flight_cached_by_head_and_retryable():
+    script = f"""
+const createPullSheet = require({json.dumps(str(PULL_SHEET))});
+const calls = [];
+let rejectFirst;
+const fetchJson = url => {{
+  calls.push(url);
+  if (calls.length === 1) return new Promise((_resolve, reject) => {{ rejectFirst = reject; }});
+  return Promise.resolve({{head_sha:'abc123', files:[]}});
+}};
+const sheet = createPullSheet({{fetchJson, storage:null}});
+const item = {{repository:'stackchain/api', number:7}};
+const first = sheet.loadReview(item, 'abc123');
+const concurrent = sheet.loadReview(item, 'abc123');
+rejectFirst(new Error('diff unavailable'));
+Promise.allSettled([first, concurrent]).then(async failed => {{
+  const retried = await sheet.loadReview(item, 'abc123');
+  const cached = await sheet.loadReview(item, 'abc123');
+  process.stdout.write(JSON.stringify({{
+    same:first === concurrent,
+    failed:failed.map(result => result.status),
+    retried,
+    cached,
+    calls,
+  }}));
+}});
+"""
+    result = subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True)
+    output = json.loads(result.stdout)
+
+    assert output["same"] is True
+    assert output["failed"] == ["rejected", "rejected"]
+    assert output["retried"]["head_sha"] == "abc123"
+    assert output["cached"] == output["retried"]
+    assert output["calls"] == [
+        "api/v1/repos/stackchain/api/pulls/7/review-data",
+        "api/v1/repos/stackchain/api/pulls/7/review-data",
+    ]
+
+
+@pytest.mark.anyio
+async def test_mobile_pull_sheet_puts_reading_before_collapsed_review_controls():
+    html = await dashboard()
+
+    body = html.index('id="pull-sheet-body"')
+    conversation = html.index('<h2>Full conversation</h2>', body)
+    composer = html.index('id="pull-comment-title"', conversation)
+    review = html.index('id="pull-review"', composer)
+    files = html.index('id="pull-files"', review)
+
+    assert '<summary><h2>Review &amp; merge</h2></summary>' in html
+    assert '<details class="pull-review" id="pull-review">' in html
+    assert 'id="pull-review-retry"' in html
+    assert 'id="pull-review-status"' in html
+    assert body < conversation < composer < review < files
+
+
 def test_pull_sheet_renders_mobile_diff_fallbacks_and_review_controls():
     script = f"""
 const createPullSheet = require({json.dumps(str(PULL_SHEET))});

tests/test_pull_api.py

@@ -54,7 +54,77 @@ async def test_assigned_pull_detail_rejects_unassigned_pull(monkeypatch):
 
 
 @pytest.mark.anyio
-async def test_gitea_assigned_pull_detail_includes_bounded_diff_previews():
+async def test_gitea_assigned_pull_detail_loads_reading_without_review_resources():
+    requests = []
+
+    async def handler(request):
+        requests.append((request.method, request.url.path))
+        if request.url.path.endswith("/pulls/7"):
+            return httpx.Response(200, json={
+                "number": 7,
+                "title": "Read this first",
+                "body": "The discussion should not wait for the diff.",
+                "state": "open",
+                "mergeable": True,
+                "head": {"sha": "abc123"},
+                "user": {"login": "alex"},
+            })
+        if request.url.path.endswith("/issues/7/comments"):
+            return httpx.Response(200, json=[{
+                "id": 9, "body": "Question", "user": {"login": "sam"},
+                "created_at": "2026-08-07T18:00:00Z",
+            }], headers={"X-Total-Count": "1"})
+        raise AssertionError(f"review resource requested during read load: {request.url.path}")
+
+    gitea_proxy.start_client(transport=httpx.MockTransport(handler))
+    try:
+        detail = await gitea_proxy.pull_completion_detail("stackchain/api", 7)
+    finally:
+        await gitea_proxy.stop_client()
+
+    assert requests == [
+        ("GET", "/api/v1/repos/stackchain/api/pulls/7"),
+        ("GET", "/api/v1/repos/stackchain/api/issues/7/comments"),
+    ]
+    assert detail["head_sha"] == "abc123"
+    assert detail["conversation"]["comments"][0]["body"] == "Question"
+    assert "files" not in detail
+    assert "ci_state" not in detail
+
+
+@pytest.mark.anyio
+async def test_assigned_pull_review_endpoint_loads_review_payload_on_demand(monkeypatch):
+    calls = []
+
+    async def assigned(repository, number):
+        calls.append(("assigned", repository, number))
+        return True
+
+    async def review(repository, number):
+        calls.append(("review", repository, number))
+        return {
+            "repository": repository, "number": number, "head_sha": "abc123",
+            "state": "open", "draft": False, "mergeable": True, "merged": False,
+            "ci_state": "success", "files": [{"filename": "src/api.py"}],
+        }
+
+    monkeypatch.setattr(main.gitea_proxy, "is_assigned_pull", assigned)
+    monkeypatch.setattr(main.gitea_proxy, "pull_completion_review", review, raising=False)
+    transport = httpx.ASGITransport(app=main.app)
+    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
+        response = await client.get("/api/v1/repos/stackchain/api/pulls/7/review-data")
+
+    assert response.status_code == 200
+    assert response.headers["cache-control"] == "no-store"
+    assert response.json()["files"] == [{"filename": "src/api.py"}]
+    assert calls == [
+        ("assigned", "stackchain/api", 7),
+        ("review", "stackchain/api", 7),
+    ]
+
+
+@pytest.mark.anyio
+async def test_gitea_assigned_pull_review_includes_bounded_diff_previews():
     async def handler(request):
         path = request.url.path
         if path.endswith("/pulls/7"):
@@ -86,7 +156,7 @@ async def test_gitea_assigned_pull_detail_includes_bounded_diff_previews():
 
     gitea_proxy.start_client(transport=httpx.MockTransport(handler))
     try:
-        detail = await gitea_proxy.pull_completion_detail("stackchain/api", 7)
+        detail = await gitea_proxy.pull_completion_review("stackchain/api", 7)
     finally:
         await gitea_proxy.stop_client()
 
@@ -94,9 +164,7 @@ async def test_gitea_assigned_pull_detail_includes_bounded_diff_previews():
     assert "+new" in detail["files"][0]["diff_lines"]
     assert detail["files"][1]["diff_binary"] is True
     assert detail["files"][1]["diff_available"] is False
-    assert detail["conversation"] == {
-        "comments": [], "page": 1, "older_page": None, "total": 0
-    }
+    assert "conversation" not in detail
 
 
 @pytest.mark.anyio