Add focused unit tests for core PR-Agent flows

Cover routing, PR processing, reviewer labels, code suggestions,
GitHub Action behavior, webhook helpers, GitLab URL handling,
LiteLLM request shaping, provider configuration errors, and PR
description helpers.

These tests target behavior that is important and likely to change,
while keeping production code untouched.

This work was developed through human-led AI collaboration using
codex-cli v0.128.0 with GPT-5.5, GitHub Copilot CLI 1.0.40 with
GPT-5.5, and Claude Opus 4.7.

Author: PeterDaveHello

tests/unittest/test_git_provider_utils.py

@@ -0,0 +1,140 @@
+from pr_agent.git_providers.utils import handle_configurations_errors
+
+
+class FakeMarkdownProvider:
+    def __init__(self):
+        self.persistent_comments = []
+
+    def is_supported(self, capability):
+        return capability == "gfm_markdown"
+
+    def publish_persistent_comment(self, body, initial_header, update_header, final_update_message):
+        self.persistent_comments.append({
+            "body": body,
+            "initial_header": initial_header,
+            "update_header": update_header,
+            "final_update_message": final_update_message,
+        })
+
+
+class FakePlainProvider:
+    def __init__(self):
+        self.comments = []
+
+    def is_supported(self, capability):
+        return False
+
+    def publish_comment(self, body):
+        self.comments.append(body)
+
+
+class FakeMarkdownCommentProvider(FakePlainProvider):
+    def is_supported(self, capability):
+        return capability == "gfm_markdown"
+
+
+def test_handle_configurations_errors_uses_persistent_comment_when_supported():
+    provider = FakeMarkdownProvider()
+
+    handle_configurations_errors([{
+        "settings": b"[config]\nmodel =",
+        "error": "Invalid value",
+        "category": "local",
+    }], provider)
+
+    assert len(provider.persistent_comments) == 1
+    comment = provider.persistent_comments[0]
+    assert comment["initial_header"] == "❌ **PR-Agent failed to apply 'local' repo settings**"
+    assert comment["update_header"] is False
+    assert comment["final_update_message"] is False
+    assert "PR-Agent failed to apply 'local' repo settings" in comment["body"]
+    assert "Invalid value" in comment["body"]
+    assert "```toml\n[config]\nmodel =\n```" in comment["body"]
+    assert "<details><summary>Configuration content:</summary>" in comment["body"]
+
+
+def test_handle_configurations_errors_keeps_markdown_details_when_persistent_comment_is_missing():
+    provider = FakeMarkdownCommentProvider()
+
+    handle_configurations_errors([{
+        "settings": b"[config]\nmodel =",
+        "error": "Invalid value",
+        "category": "local",
+    }], provider)
+
+    assert len(provider.comments) == 1
+    assert "PR-Agent failed to apply 'local' repo settings" in provider.comments[0]
+    assert "Invalid value" in provider.comments[0]
+    assert "```toml\n[config]\nmodel =\n```" in provider.comments[0]
+    assert "<details><summary>Configuration content:</summary>" in provider.comments[0]
+
+
+def test_handle_configurations_errors_uses_plain_comment_without_markdown_support():
+    provider = FakePlainProvider()
+
+    handle_configurations_errors([{
+        "settings": b"[config]\nmodel =",
+        "error": "Invalid value",
+        "category": "local",
+    }], provider)
+
+    assert len(provider.comments) == 1
+    assert "❌ **PR-Agent failed to apply 'local' repo settings**" in provider.comments[0]
+    assert "Invalid value" in provider.comments[0]
+    assert "```toml\n[config]\nmodel =\n```" in provider.comments[0]
+    assert "<details>" not in provider.comments[0]
+
+
+def test_handle_configurations_errors_returns_without_errors():
+    provider = FakePlainProvider()
+
+    handle_configurations_errors([], provider)
+
+    assert provider.comments == []
+
+
+def test_handle_configurations_errors_publishes_each_error():
+    provider = FakePlainProvider()
+
+    handle_configurations_errors([
+        {
+            "settings": b"[config]\nmodel =",
+            "error": "First error",
+            "category": "local",
+        },
+        {
+            "settings": b"[pr_reviewer]\nnum_max_findings =",
+            "error": "Second error",
+            "category": "global",
+        },
+    ], provider)
+
+    assert len(provider.comments) == 2
+    assert "First error" in provider.comments[0]
+    assert "[config]\nmodel =" in provider.comments[0]
+    assert "Second error" in provider.comments[1]
+    assert "[pr_reviewer]\nnum_max_findings =" in provider.comments[1]
+
+
+def test_handle_configurations_errors_ignores_empty_sentinel_entry():
+    provider = FakePlainProvider()
+
+    handle_configurations_errors([None], provider)
+
+    assert provider.comments == []
+
+
+def test_handle_configurations_errors_skips_empty_sentinel_entries_in_mixed_list():
+    provider = FakePlainProvider()
+
+    handle_configurations_errors([
+        None,
+        {
+            "settings": b"[config]\nmodel =",
+            "error": "Only error",
+            "category": "local",
+        },
+    ], provider)
+
+    assert len(provider.comments) == 1
+    assert "Only error" in provider.comments[0]

tests/unittest/test_github_action_runner_core.py

@@ -0,0 +1,105 @@
+import copy
+import json
+
+import pytest
+
+import pr_agent.servers.github_action_runner as github_action_runner
+from pr_agent.config_loader import get_settings
+
+
+def test_is_true_accepts_bool_and_case_insensitive_true_string():
+    assert github_action_runner.is_true(True) is True
+    assert github_action_runner.is_true(False) is False
+    assert github_action_runner.is_true("TRUE") is True
+    assert github_action_runner.is_true("false") is False
+    assert github_action_runner.is_true(None) is False
+
+
+@pytest.mark.asyncio
+async def test_run_action_returns_when_required_env_is_missing(monkeypatch, capsys):
+    monkeypatch.delenv("GITHUB_EVENT_NAME", raising=False)
+
+    await github_action_runner.run_action()
+
+    assert "GITHUB_EVENT_NAME not set" in capsys.readouterr().out
+
+
+@pytest.mark.asyncio
+async def test_run_action_invokes_enabled_auto_tools_for_pull_request_event(monkeypatch, tmp_path):
+    settings = get_settings()
+    original_is_auto_command = settings.config.get("is_auto_command", False)
+    original_final_update_message = settings.pr_description.final_update_message
+    original_response_language = settings.config.response_language
+    had_github_settings = "GITHUB" in settings
+    original_github_settings = copy.deepcopy(settings.get("GITHUB", None))
+    had_github_action_config = "GITHUB_ACTION_CONFIG" in settings
+    original_github_action_config = copy.deepcopy(settings.get("GITHUB_ACTION_CONFIG", None))
+    event_path = tmp_path / "event.json"
+    event_path.write_text(json.dumps({
+        "action": "opened",
+        "pull_request": {
+            "url": "https://api.github.com/repos/org/repo/pulls/1",
+            "html_url": "https://github.com/org/repo/pull/1",
+        },
+    }))
+    monkeypatch.setenv("GITHUB_EVENT_NAME", "pull_request")
+    monkeypatch.setenv("GITHUB_EVENT_PATH", str(event_path))
+    monkeypatch.setenv("GITHUB_TOKEN", "token")
+    monkeypatch.setattr(github_action_runner, "apply_repo_settings", lambda pr_url: None)
+
+    def fake_get_setting_or_env(key, default=None):
+        values = {
+            "GITHUB_ACTION_CONFIG.PR_ACTIONS": ["opened"],
+            "GITHUB_ACTION.AUTO_DESCRIBE": True,
+            "GITHUB_ACTION.AUTO_REVIEW": False,
+            "GITHUB_ACTION.AUTO_IMPROVE": True,
+            "GITHUB_ACTION_CONFIG.ENABLE_OUTPUT": True,
+        }
+        return values.get(key, default)
+
+    monkeypatch.setattr(github_action_runner, "get_setting_or_env", fake_get_setting_or_env)
+    runs = []
+
+    class FakeTool:
+        name = "base"
+
+        def __init__(self, pr_url):
+            self.pr_url = pr_url
+
+        async def run(self):
+            runs.append((self.name, self.pr_url))
+
+    class FakeDescription(FakeTool):
+        name = "describe"
+
+    class FakeReviewer(FakeTool):
+        name = "review"
+
+    class FakeSuggestions(FakeTool):
+        name = "improve"
+
+    monkeypatch.setattr(github_action_runner, "PRDescription", FakeDescription)
+    monkeypatch.setattr(github_action_runner, "PRReviewer", FakeReviewer)
+    monkeypatch.setattr(github_action_runner, "PRCodeSuggestions", FakeSuggestions)
+
+    try:
+        settings.config.response_language = "en-us"
+
+        await github_action_runner.run_action()
+
+        assert runs == [
+            ("describe", "https://api.github.com/repos/org/repo/pulls/1"),
+            ("improve", "https://api.github.com/repos/org/repo/pulls/1"),
+        ]
+    finally:
+        settings.config.is_auto_command = original_is_auto_command
+        settings.pr_description.final_update_message = original_final_update_message
+        settings.config.response_language = original_response_language
+        if had_github_settings:
+            settings.set("GITHUB", original_github_settings)
+        else:
+            settings.unset("GITHUB", force=True)
+        if had_github_action_config:
+            settings.set("GITHUB_ACTION_CONFIG", original_github_action_config)
+        else:
+            settings.unset("GITHUB_ACTION_CONFIG", force=True)

tests/unittest/test_gitlab_provider.py

@@ -95,7 +95,7 @@ def test_create_or_update_pr_file_create_new(self, gitlab_provider, mock_project
 
     def test_create_or_update_pr_file_update_existing(self, gitlab_provider, mock_project):
         mock_file = MagicMock(ProjectFile)
-        mock_file.decode.return_value = "# Old changelog content"
+        mock_file.content = "# Old changelog content"
         mock_project.files.get.return_value = mock_file
 
         new_content = "# New changelog content"
@@ -106,8 +106,9 @@ def test_create_or_update_pr_file_update_existing(self, gitlab_provider, mock_pr
         )
 
         mock_project.files.get.assert_called_once_with("CHANGELOG.md", "feature-branch")
-        mock_file.content = new_content
+        assert mock_file.content == new_content
         mock_file.save.assert_called_once_with(branch="feature-branch", commit_message=commit_message)
+        mock_project.files.create.assert_not_called()
 
     def test_create_or_update_pr_file_update_exception(self, gitlab_provider, mock_project):
         mock_project.files.get.side_effect = Exception("Network error")
@@ -174,13 +175,18 @@ def test_project_by_path_requires_exact_match(self, gitlab_provider):
         gitlab_provider.gl.projects.get.reset_mock()
         gitlab_provider.gl.projects.get.side_effect = Exception("not found")
         fake = MagicMock()
+        fake.id = "mismatched-project-id"
         fake.path_with_namespace = "other/group/repo"
         gitlab_provider.gl.projects.list.return_value = [fake]
 
         result = gitlab_provider._project_by_path("group/repo")
 
         assert result is None
-        assert gitlab_provider.gl.projects.get.call_count == 2
+        gitlab_provider.gl.projects.list.assert_called_once()
+        list_kwargs = gitlab_provider.gl.projects.list.call_args.kwargs
+        assert list_kwargs["search"] == "repo"
+        assert list_kwargs["membership"] is True
+        assert all(call.args[0] != fake.id for call in gitlab_provider.gl.projects.get.call_args_list)
 
     def test_compare_submodule_cached(self, gitlab_provider):
         proj = MagicMock()
@@ -192,3 +198,37 @@ def test_compare_submodule_cached(self, gitlab_provider):
         assert first == second == [{"diff": "d"}]
         m_pbp.assert_called_once_with("grp/repo")
         proj.repository_compare.assert_called_once_with("old", "new")
+
+    def test_compare_submodule_cache_hit_skips_project_resolution(self, gitlab_provider):
+        cached_diffs = [{"diff": "d"}]
+        gitlab_provider._submodule_cache[("grp/repo", "old", "new")] = cached_diffs
+
+        with patch.object(gitlab_provider, "_project_by_path") as m_pbp:
+            result = gitlab_provider._compare_submodule("grp/repo", "old", "new")
+
+        assert result == cached_diffs
+        m_pbp.assert_not_called()
+
+    def test_parse_merge_request_url_handles_nested_project_paths(self, gitlab_provider):
+        project_path, mr_id = gitlab_provider._parse_merge_request_url(
+            "https://gitlab.com/group/subgroup/repo/-/merge_requests/123"
+        )
+
+        assert project_path == "group/subgroup/repo"
+        assert mr_id == 123
+
+    def test_get_line_link_handles_file_and_line_ranges(self, gitlab_provider):
+        gitlab_provider.gl.url = "https://gitlab.com"
+        gitlab_provider.id_project = "group/repo"
+        gitlab_provider.mr = MagicMock()
+        gitlab_provider.mr.source_branch = "feature/cache"
+
+        assert gitlab_provider.get_line_link("src/app.py", -1) == (
+            "https://gitlab.com/group/repo/-/blob/feature/cache/src/app.py?ref_type=heads"
+        )
+        assert gitlab_provider.get_line_link("src/app.py", 10) == (
+            "https://gitlab.com/group/repo/-/blob/feature/cache/src/app.py?ref_type=heads#L10"
+        )
+        assert gitlab_provider.get_line_link("src/app.py", 10, 12) == (
+            "https://gitlab.com/group/repo/-/blob/feature/cache/src/app.py?ref_type=heads#L10-12"
+        )