test: add ContextBuilder prompt unit coverage

tests/unit/test_context_builder.py

@@ -0,0 +1,124 @@
+from __future__ import annotations
+
+import unittest
+
+from contribarena.config.schema import (
+    DiscoveryConfig,
+    GovernanceConfig,
+    OwnedRepositoryPolicy,
+    RepoCandidate,
+    RepoSearchFilters,
+    RunConfig,
+    RunSection,
+    WorkspaceConfig,
+)
+from contribarena.engine.context import ContextBuilder
+
+
+def _candidate(
+    owner: str = "qWaitCrypto",
+    repo: str = "ContribArena",
+    notes: str | None = "owned calibration target",
+) -> RepoCandidate:
+    return RepoCandidate(
+        owner=owner,
+        repo=repo,
+        url=f"https://github.com/{owner}/{repo}",
+        branch="main",
+        notes=notes,
+    )
+
+
+def _config(
+    *,
+    mode: str = "shadow",
+    candidates: list[RepoCandidate] | None = None,
+    query: str = "agent framework",
+    filters: RepoSearchFilters | None = None,
+) -> RunConfig:
+    candidates = list(candidates or [])
+    governance = GovernanceConfig()
+    if mode == "owned_live" and candidates:
+        governance.owned_repositories = [
+            OwnedRepositoryPolicy(owner=candidates[0].owner, repo=candidates[0].repo)
+        ]
+    return RunConfig(
+        run=RunSection(mode=mode),
+        discovery=DiscoveryConfig(
+            candidates=candidates,
+            query=query,
+            filters=filters or RepoSearchFilters(),
+        ),
+        workspace=WorkspaceConfig(),
+        governance=governance,
+    )
+
+
+class ContextBuilderTest(unittest.TestCase):
+    def test_owned_live_prompt_includes_owned_live_boundary_and_candidate_notes(self) -> None:
+        prompt = ContextBuilder().build_system_prompt(
+            _config(mode="owned_live", candidates=[_candidate()])
+        )
+
+        self.assertIn("The run is owned-live mode", prompt)
+        self.assertIn("live GitHub writes are executed only by the harness", prompt)
+        self.assertIn(
+            "- qWaitCrypto/ContribArena: https://github.com/qWaitCrypto/ContribArena (owned calibration target)",
+            prompt,
+        )
+        self.assertIn("Discovery query: agent framework", prompt)
+
+    def test_external_live_prompt_includes_fork_only_boundary(self) -> None:
+        prompt = ContextBuilder().build_system_prompt(
+            _config(mode="external_live", candidates=[_candidate()])
+        )
+
+        self.assertIn("The run is external-live mode", prompt)
+        self.assertIn("External PR submission is fork-only.", prompt)
+        self.assertIn("governance gates", prompt)
+
+    def test_shadow_prompt_includes_no_pull_request_boundary(self) -> None:
+        prompt = ContextBuilder().build_system_prompt(
+            _config(mode="shadow", candidates=[_candidate()])
+        )
+
+        self.assertIn("The run is shadow mode", prompt)
+        self.assertIn("do not open pull requests or write comments", prompt)
+
+    def test_candidate_without_notes_uses_no_notes_placeholder(self) -> None:
+        prompt = ContextBuilder().build_system_prompt(
+            _config(candidates=[_candidate(owner="octo", repo="demo", notes=None)])
+        )
+
+        self.assertIn("- octo/demo: https://github.com/octo/demo (no notes)", prompt)
+
+    def test_empty_candidate_list_uses_repo_search_fallback_and_serializes_filters(self) -> None:
+        prompt = ContextBuilder().build_system_prompt(
+            _config(
+                candidates=[],
+                query="",
+                filters=RepoSearchFilters(language="Python", stars_min=0),
+            )
+        )
+
+        self.assertIn("Discovery query: n/a", prompt)
+        self.assertIn("Discovery filters: {'language': 'Python', 'stars_min': 0}", prompt)
+        self.assertIn(
+            "- no fixed candidates; use repo_search with configured query/filters",
+            prompt,
+        )
+
+    def test_prompt_includes_runtime_and_guidance_contracts(self) -> None:
+        prompt = ContextBuilder().build_system_prompt(
+            _config(candidates=[_candidate()])
+        )
+
+        self.assertIn("Call aci_runtime_get_context(scope='run') early", prompt)
+        self.assertIn("Move phases only through aci_goal_update", prompt)
+        self.assertIn("If guidance is available, read the returned path", prompt)
+        self.assertIn("Before editing, check repository-local guidance", prompt)
+        self.assertIn("Choose a low-risk task and return a structured completion result.", prompt)
+
+
+if __name__ == "__main__":
+    unittest.main()