feat: preview mobile review diffs (#123)

tests/test_gitea_work_search.py

@@ -159,6 +159,13 @@ async def test_pull_review_detail_combines_pr_files_status_and_reviews(monkeypat
 
     monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
 
+    async def fake_fetch_text(path, max_bytes):
+        assert path == "repos/stackchain/api/pulls/7.diff"
+        assert max_bytes == gitea_proxy.REVIEW_DIFF_MAX_BYTES
+        return "", False
+
+    monkeypatch.setattr(gitea_proxy, "fetch_text", fake_fetch_text)
+
     detail = await gitea_proxy.pull_review_detail("stackchain/api", 7)
 
     assert requested_paths == [
@@ -173,3 +180,55 @@ async def test_pull_review_detail_combines_pr_files_status_and_reviews(monkeypat
     assert detail["reviews"][0]["state"] == "APPROVED"
     assert len(detail["files"]) == 1
     assert len(detail["reviews"]) == 1
+
+
+@pytest.mark.anyio
+async def test_pull_review_detail_attaches_bounded_per_file_diff_previews(monkeypatch):
+    async def fake_fetch(path):
+        if path.endswith("/pulls/7"):
+            return {
+                "title": "Review API",
+                "head": {"sha": "abc123"},
+                "user": {"login": "alex"},
+            }
+        if path.endswith("/files"):
+            return [
+                {"filename": "src/api.py", "status": "modified"},
+                {"filename": "assets/logo.png", "status": "modified"},
+            ]
+        if path.endswith("/reviews"):
+            return []
+        return {"state": "success"}
+
+    diff = """diff --git a/src/api.py b/src/api.py
+index 123..456 100644
+--- a/src/api.py
++++ b/src/api.py
+@@ -1,2 +1,3 @@
+ context
+-old <value>
++new <value>
+diff --git a/assets/logo.png b/assets/logo.png
+Binary files a/assets/logo.png and b/assets/logo.png differ
+"""
+
+    async def fake_fetch_text(path, max_bytes):
+        assert path == "repos/stackchain/api/pulls/7.diff"
+        return diff, True
+
+    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
+    monkeypatch.setattr(gitea_proxy, "fetch_text", fake_fetch_text)
+
+    detail = await gitea_proxy.pull_review_detail("stackchain/api", 7)
+
+    source, binary = detail["files"]
+    assert source["diff_lines"] == [
+        "@@ -1,2 +1,3 @@",
+        " context",
+        "-old <value>",
+        "+new <value>",
+    ]
+    assert source["diff_truncated"] is True
+    assert source["diff_available"] is True
+    assert binary["diff_available"] is False
+    assert binary["diff_binary"] is True

tests/test_my_work.py

@@ -172,6 +172,35 @@ controller.load({{ repository: 'stackchain/api', number: 7 }}).then(detail =>
     }
 
 
+def test_review_diff_rows_escape_content_and_toggle_accessibly():
+    script = f"""
+const reviewSheet = require({json.dumps(str(REVIEW_SHEET))});
+const escapeHtml = value => String(value)
+  .replaceAll('&', '&amp;').replaceAll('<', '&lt;').replaceAll('>', '&gt;');
+const html = reviewSheet.renderDiffFile({{
+  filename: 'src/<api>.py', status: 'modified', additions: 1, deletions: 1,
+  diff_available: true, diff_truncated: true,
+  diff_lines: ['@@ -1 +1 @@', '-old <token>', '+new & safe']
+}}, 2, escapeHtml);
+const button = {{ attrs: {{ 'aria-expanded': 'false' }}, getAttribute(k) {{ return this.attrs[k]; }}, setAttribute(k,v) {{ this.attrs[k]=v; }} }};
+const panel = {{ hidden: true }};
+reviewSheet.toggleDiff(button, panel);
+process.stdout.write(JSON.stringify({{ html, expanded: button.attrs['aria-expanded'], hidden: panel.hidden }}));
+"""
+    result = subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )
+    output = json.loads(result.stdout)
+
+    assert 'aria-expanded="false"' in output["html"]
+    assert 'src/&lt;api&gt;.py' in output["html"]
+    assert '-old &lt;token&gt;' in output["html"]
+    assert '+new &amp; safe' in output["html"]
+    assert 'Preview truncated' in output["html"]
+    assert output["expanded"] == "true"
+    assert output["hidden"] is False
+
+
 @pytest.mark.anyio
 async def test_review_requests_open_an_accessible_mobile_detail_sheet():
     html = await dashboard()
@@ -184,6 +213,8 @@ async def test_review_requests_open_an_accessible_mobile_detail_sheet():
     assert '@media (max-width: 600px)' in html
     assert '.review-sheet-panel' in html and 'width:100%' in html
     assert '.review-action' in html and 'min-height:44px' in html
+    assert '.review-file-toggle' in html and 'min-height:44px' in html
+    assert '.review-diff' in html and 'overflow-x:auto' in html
 
 
 @pytest.mark.anyio