feat: cancel pending pull review requests (Closes #1340)

src/gitea_proxy.py

@@ -2028,6 +2028,53 @@ async def request_assigned_pull_review(
     }
 
 
+async def cancel_assigned_pull_review(
+    repository: str, number: int, reviewer: str, expected_head_sha: str
+) -> dict:
+    login, pull = await _current_login_and_target(
+        f"repos/{repository}/pulls/{number}"
+    )
+    head = pull.get("head") if isinstance(pull.get("head"), dict) else {}
+    requested = [
+        item["login"] for item in (pull.get("requested_reviewers") or [])
+        if isinstance(item, dict) and isinstance(item.get("login"), str)
+    ]
+    if (
+        pull.get("state") != "open"
+        or pull.get("merged") is True
+        or not _login_in_users(login, pull.get("assignees"))
+        or head.get("sha") != expected_head_sha
+        or reviewer not in requested
+    ):
+        raise IssueNotAvailableError("Pending review request changed")
+    response = await _get_client().request(
+        "DELETE",
+        f"/api/v1/repos/{repository}/pulls/{number}/requested_reviewers",
+        headers=_auth(),
+        json={"reviewers": [reviewer]},
+    )
+    response.raise_for_status()
+    confirmed_response = await _get_client().get(
+        f"/api/v1/repos/{repository}/pulls/{number}", headers=_auth()
+    )
+    confirmed_response.raise_for_status()
+    confirmed = confirmed_response.json()
+    remaining = [
+        item["login"] for item in (confirmed.get("requested_reviewers") or [])
+        if isinstance(item, dict) and isinstance(item.get("login"), str)
+    ] if isinstance(confirmed, dict) else []
+    confirmed_head = confirmed.get("head") if isinstance(confirmed, dict) and isinstance(confirmed.get("head"), dict) else {}
+    if reviewer in remaining or confirmed_head.get("sha") != expected_head_sha:
+        raise ValueError("Gitea did not confirm reviewer cancellation")
+    return {
+        "repository": repository,
+        "number": number,
+        "head_sha": expected_head_sha,
+        "requested_reviewers": remaining,
+        "reviewer": reviewer,
+    }
+
+
 async def _change_assigned_pull_owners(
     repository: str, number: int, recipient: str | None
 ) -> dict:

src/main.py

@@ -6773,6 +6773,34 @@ async def request_assigned_pull_review(
     return JSONResponse(result)
 
 
+@app.delete("/api/v1/repos/{owner}/{repo}/pulls/{number}/request-review")
+async def cancel_assigned_pull_review(
+    request: PullReviewRequest,
+    owner: str,
+    repo: str,
+    number: int = PathParam(gt=0),
+) -> JSONResponse:
+    try:
+        result = await asyncio.wait_for(
+            gitea_proxy.cancel_assigned_pull_review(
+                f"{owner}/{repo}", number, request.reviewer, request.expected_head_sha
+            ),
+            timeout=ISSUE_ACTION_TIMEOUT_SECONDS,
+        )
+    except gitea_proxy.IssueNotAvailableError:
+        return JSONResponse(
+            {"error": "The pull request or reviewer changed. Reload before cancelling the request."},
+            status_code=409,
+        )
+    except Exception:
+        return JSONResponse(
+            {"error": "The cancellation could not be confirmed. Refresh review data before retrying."},
+            status_code=503,
+            headers={"Retry-After": "1"},
+        )
+    return JSONResponse(result)
+
+
 @app.patch("/api/v1/repos/{owner}/{repo}/pulls/{number}/release")
 async def release_assigned_pull(
     owner: str, repo: str, number: int = PathParam(gt=0)