The pull request is the subject, not the input

backend/druks/contrib/review/templates/review_pull_request.md

@@ -1,6 +1,6 @@
 # Pull Request Reviewer
 
-You are reviewing pull request #{{ workflow.input.pr_number }} on `{{ workflow.input.repo }}`,
+You are reviewing pull request #{{ workflow.subject.number }} on `{{ workflow.subject.repo }}`,
 at {{ workflow.input.requested_by }}'s request.
 
 The repo is cloned at `{{ workspace.repo_path }}`, and `gh` is authenticated there as the

backend/druks/contrib/review/workflows.py

@@ -45,20 +45,18 @@ async def dispatch(cls, *, repo: str, pr_number: int, requested_by: str) -> str:
         return await cls.start(
             subject=PullRequest.get(repo, pr_number),
             account_id=account.id if account else None,
-            repo=repo,
-            pr_number=pr_number,
             requested_by=requested_by,
         )
 
-    async def run(self, repo: str, pr_number: int, requested_by: str) -> None:
+    async def run(self, requested_by: str) -> None:
         await Review.review_pull_request()
 
     async def get_workspace_kwargs(self, sandbox: "Sandbox") -> dict[str, Any]:
         # Cloned at the default branch — the reviewer checks the pull request out itself.
         # The token is the reviewer app's: it authenticates the clone and ``gh``, so the
         # review is authored under that identity. Siblings stay uncloned — the reviewer
         # clones the ones it opens, into a directory that must exist for the grant to hold.
-        repo = self.input.repo
+        repo = self.subject.repo
         github_token = await get_reviewer_github_client(load_settings()).token_for_repo(repo)
         await sandbox.write_secret(
             secret=github_token, remote=get_github_token_remote_path(sandbox.ssh_username)
@@ -77,7 +75,7 @@ async def get_workspace_kwargs(self, sandbox: "Sandbox") -> dict[str, Any]:
         }
 
     async def get_prompt_context(self, **context: Any) -> dict[str, Any]:
-        target = ProjectRepo.get_for_repo(self.input.repo, raise_on_missing=True)
+        target = ProjectRepo.get_for_repo(self.subject.repo, raise_on_missing=True)
         return {
             "siblings": target.siblings(),
             **await super().get_prompt_context(**context),

backend/tests/test_review.py

@@ -1,11 +1,16 @@
 from pathlib import Path
+from types import SimpleNamespace
 
 import pytest
 from druks.contrib.review.datastructures import PullRequest
 from druks.contrib.review.workflows import PullRequestReview
+from druks.prompts import render_prompt
 from druks.testing import seed_run
+from druks.workflows import _bind_instance
 from fastapi.testclient import TestClient
 
+pytestmark = pytest.mark.usefixtures("druks_without_remote_config")
+
 
 @pytest.fixture
 def client(tmp_path: Path, druks_db, monkeypatch):
@@ -53,3 +58,43 @@ def test_the_pull_request_board_and_page_mount(client: TestClient, druks_db):
     assert detail["summary"]["pullRequestUrl"] == "https://github.com/acme/app/pull/7"
     assert [entry["kind"] for entry in detail["timeline"]] == [PullRequestReview.kind]
     assert client.get("/api/review/pull_request/acme/app").status_code == 404
+
+
+def test_the_run_carries_the_pull_request_once():
+    # The repo and the number are the subject, so they are not also input: the body
+    # takes what only the request knows.
+    assert list(PullRequestReview._run_input_model.model_fields) == ["requested_by"]
+
+
+def test_a_queued_run_replays_through_its_subject():
+    # A review enqueued before the repo and number came off the input still carries
+    # them in its durable payload. The extra keys are ignored and the subject rides
+    # separately, so the body binds and reads the pull request off the declaration.
+    instance, run_kwargs = _bind_instance(
+        PullRequestReview,
+        PullRequest.get("acme/app", 7).identity,
+        {"repo": "acme/app", "pr_number": 7, "requested_by": "dev@example.com"},
+    )
+
+    assert run_kwargs == {"requested_by": "dev@example.com"}
+    assert (instance.subject.repo, instance.subject.number) == ("acme/app", 7)
+
+
+async def test_the_reviewer_prompt_names_the_pull_request_it_is_about():
+    workflow = SimpleNamespace(
+        subject=PullRequest.get("acme/app", 7),
+        input=SimpleNamespace(requested_by="dev@example.com"),
+    )
+    workspace = SimpleNamespace(
+        repo_path="/home/agent/work/repo", related_root="/home/agent/related"
+    )
+
+    output = await render_prompt(
+        "review/review_pull_request.md",
+        workflow=workflow,
+        workspace=workspace,
+        siblings=[],
+    )
+
+    assert "pull request #7 on `acme/app`" in output
+    assert "at dev@example.com's request" in output