feat: load pull review feedback on demand (Closes #1342)

tests/e2e/test_mobile_pull_reviewer_feedback_release.py

@@ -90,3 +90,83 @@ def test_mobile_received_review_feedback_opens_matching_change(viewport):
     assert metrics["focused"] is True
     assert "Reviewed head old-head" in metrics["reviewedHead"]
     assert metrics["updatedReviewVisible"] is True
+
+
+@pytest.mark.parametrize("viewport", [(320, 568), (390, 844)])
+def test_mobile_pull_review_retries_inline_feedback_without_losing_core_review(viewport):
+    playwright = pytest.importorskip("playwright.sync_api")
+    html = (ROOT / "frontend" / "index.html").read_text()
+    detail = {
+        "state": "open", "draft": False, "mergeable": True, "merged": False,
+        "ci_state": "success", "head_sha": "abc1234",
+        "reviewers": [{
+            "login": "sam", "review_id": 8, "status": "changes_requested",
+            "head_sha": "abc1234", "blocking": True,
+            "summary": "Please handle the empty state.",
+        }],
+        "files": [],
+    }
+
+    with playwright.sync_playwright() as runtime:
+        try:
+            browser = runtime.chromium.launch(headless=True)
+        except Exception as error:
+            pytest.skip(f"Chromium is not installed: {error}")
+        page = browser.new_page(viewport={"width": viewport[0], "height": viewport[1]})
+        page.set_content(html, wait_until="domcontentloaded")
+        page.add_style_tag(path=ROOT / "frontend" / "dashboard.css")
+        page.add_script_tag(path=ROOT / "frontend" / "pull-sheet.js")
+        page.evaluate(
+            """detail => {
+                window.lazyFeedbackDetail = detail;
+                window.lazyFeedbackItem = {repository:'stackchain/api', number:7, key:'stackchain/api#7'};
+                let attempts = 0;
+                const controller = createPullSheet({
+                    storage:null,
+                    fetchJson:() => {
+                        attempts += 1;
+                        if (attempts === 1) return Promise.reject(new Error('feedback unavailable'));
+                        return Promise.resolve({
+                            review_id:8, head_sha:'abc1234', reviewed_head_sha:'abc1234',
+                            comments:[{id:99, path:'src/api.py', body:'Return before parsing.', line:12}],
+                        });
+                    },
+                });
+                createPullSheet.bindFeedbackControls(
+                    document, controller, () => window.lazyFeedbackItem,
+                    () => window.lazyFeedbackDetail, () => 'timmy'
+                );
+                document.querySelector('#pull-sheet').classList.add('open');
+                document.querySelector('#pull-review').open = true;
+                const eligibility = createPullSheet.review(detail, null, document);
+                document.querySelector('#pull-merge-state').textContent = eligibility.reason;
+            }""",
+            detail,
+        )
+
+        page.locator(".pull-review-feedback summary").click()
+        load = page.get_by_role("button", name="Load inline feedback")
+        load.click()
+        retry = page.get_by_role("button", name="Retry feedback")
+        retry.wait_for()
+        retry.click()
+        page.get_by_text("Return before parsing.").wait_for()
+        metrics = page.evaluate(
+            """() => {
+                const details = document.querySelector('.pull-review-feedback');
+                const address = document.querySelector('[data-address-review-feedback]');
+                return {
+                    scrollWidth: document.documentElement.scrollWidth,
+                    clientWidth: document.documentElement.clientWidth,
+                    blocker: document.querySelector('#pull-merge-state').textContent,
+                    feedback: details.textContent,
+                    addressHeight: address.getBoundingClientRect().height,
+                };
+            }"""
+        )
+        browser.close()
+
+    assert metrics["scrollWidth"] <= metrics["clientWidth"]
+    assert "requested changes" in metrics["blocker"]
+    assert "Return before parsing." in metrics["feedback"]
+    assert metrics["addressHeight"] >= 44