Add merge conflict detection for pull requests (#12)

When a PR has merge conflicts, GitHub doesn't run workflows, but cimonitor previously didn't report this. Now cimonitor detects and reports merge conflicts using the GitHub API's mergeable state.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

Author: irskep

.claude/commands/submit.md

@@ -0,0 +1,34 @@
+# Submit changes
+
+1. `mise run format && mise run lint`, then fix issues
+2. `mise run tests`, then fix issues
+3. Review changes with `git status` and `git diff`, checking for commits vs the merge-base of origin/main, as well as unstaged cahnges, and staged changes
+4. Stage and commit changes:
+
+   ```bash
+   git add . # or an appropriate set of files
+   git commit -m "$(cat <<'EOF'
+   [Your commit message here]
+
+   🤖 Generated with [Claude Code](https://claude.ai/code)
+
+   Co-Authored-By: Claude <noreply@anthropic.com>
+   EOF
+   )"
+   ```
+
+   Avoid unnecessary lists in your commit message. Avoid adding filler to lists to make them longer.
+5. `git push -u origin HEAD`
+6. Create a PR:
+
+   ```bash
+   gh pr create --title "[PR Title]" --body "$(cat <<'EOF'
+   <message>
+
+   🤖 Generated with [Claude Code](https://claude.ai/code)
+   EOF
+   )"
+   ```
+
+   Avoid unnecessary lists in the PR description. PR descriptions do not have a minimum length, just do what's appropriate. Adding fluff and over-emphasizing minor points makes you seem less intelligent.
+7. Monitor CI with `uv run cimonitor watch --pr=<pr-number>`

.claude/commands/update.md

@@ -0,0 +1,21 @@
+1. 1. `mise run format && mise run lint`, then fix issues
+2. `mise run tests`, then fix issues
+3. Review changes with `git status` and `git diff`, checking for commits vs origin/{branch}, as well as unstaged cahnges, and staged changes
+4. Stage and commit changes:
+
+   ```bash
+   git add . # or an appropriate set of files
+   git commit -m "$(cat <<'EOF'
+   [Your commit message here]
+
+   🤖 Generated with [Claude Code](https://claude.ai/code)
+
+   Co-Authored-By: Claude <noreply@anthropic.com>
+   EOF
+   )"
+   ```
+
+   Avoid unnecessary lists in your commit message. Avoid adding filler to lists to make them longer.
+5. `git push -u origin HEAD`
+6. Edit the existing open pull request using the `gh` command
+7. Monitor CI with `uv run cimonitor watch --pr=<pr-number>`

cimonitor/cli.py

@@ -146,7 +146,7 @@ def get_target_info(fetcher, repo, branch, commit, pr, verbose=False):
             click.echo(f"Branch: {current_branch}")
             click.echo(f"Latest commit: {commit_sha}")
 
-    return owner, repo_name, commit_sha, target_description
+    return owner, repo_name, commit_sha, target_description, pr_number
 
 
 @click.group(invoke_without_command=True)
@@ -167,12 +167,19 @@ def status(repo, branch, commit, pr, verbose):
     try:
         validate_target_options(branch, commit, pr)
         fetcher = GitHubCIFetcher()
-        owner, repo_name, commit_sha, target_description = get_target_info(
+        owner, repo_name, commit_sha, target_description, pr_number = get_target_info(
             fetcher, repo, branch, commit, pr, verbose
         )
 
         # Get CI status using business logic
-        ci_status = get_ci_status(fetcher, owner, repo_name, commit_sha, target_description)
+        ci_status = get_ci_status(
+            fetcher, owner, repo_name, commit_sha, target_description, pr_number
+        )
+
+        # Check for merge conflicts first - only show if there are actual conflicts
+        if ci_status.merge_conflict_info and _has_merge_conflicts(ci_status.merge_conflict_info):
+            _handle_merge_conflict_status(ci_status)
+            return
 
         # Early return for no failures
         if not ci_status.has_failures:
@@ -207,7 +214,7 @@ def logs(repo, branch, commit, pr, verbose, raw, job_id, show_groups, step_filte
     try:
         validate_target_options(branch, commit, pr)
         fetcher = GitHubCIFetcher()
-        owner, repo_name, commit_sha, target_description = get_target_info(
+        owner, repo_name, commit_sha, target_description, pr_number = get_target_info(
             fetcher, repo, branch, commit, pr, verbose
         )
 
@@ -249,7 +256,7 @@ def watch(repo, branch, commit, pr, verbose, until_complete, until_fail, retry):
         _validate_watch_options(until_complete, until_fail, retry)
 
         fetcher = GitHubCIFetcher()
-        owner, repo_name, commit_sha, target_description = get_target_info(
+        owner, repo_name, commit_sha, target_description, pr_number = get_target_info(
             fetcher, repo, branch, commit, pr, verbose
         )
 
@@ -587,6 +594,74 @@ def _display_step_status_summary(step_status):
             click.echo(f"  {icon} {step_name} ({conclusion})")
 
 
+def _has_merge_conflicts(merge_info):
+    """Check if the merge info indicates actual merge conflicts."""
+    if not merge_info:
+        return False
+
+    mergeable = merge_info.get("mergeable")
+    mergeable_state = merge_info.get("mergeable_state")
+
+    # These states indicate merge conflicts or blocking issues
+    return (
+        mergeable is False
+        or mergeable_state == "dirty"
+        or mergeable_state == "blocked"
+        or merge_info.get("state") == "closed"
+        or (mergeable is None and mergeable_state == "unknown")
+    )
+
+
+def _handle_merge_conflict_status(ci_status):
+    """Handle and display merge conflict status information."""
+    merge_info = ci_status.merge_conflict_info
+    if not merge_info:
+        return
+
+    mergeable = merge_info.get("mergeable")
+    mergeable_state = merge_info.get("mergeable_state")
+    state = merge_info.get("state")
+    draft = merge_info.get("draft", False)
+
+    # Check for merge conflicts (dirty state indicates conflicts)
+    if mergeable is False or mergeable_state == "dirty":
+        click.echo(f"🚫 {ci_status.target_description} has merge conflicts!")
+        click.echo("💡 No workflows will run until merge conflicts are resolved.")
+        click.echo(f"🔍 Mergeable state: {mergeable_state}")
+        if merge_info.get("base_ref"):
+            click.echo(f"📋 Base branch: {merge_info['base_ref']}")
+        click.echo("🛠️  Please resolve conflicts and push updates to trigger workflows.")
+        return
+
+    # Check for other blocking states
+    if mergeable_state == "blocked":
+        click.echo(f"🔒 {ci_status.target_description} is blocked from merging.")
+        click.echo(
+            "💡 This may be due to required status checks, reviews, or other branch protection rules."
+        )
+        if not ci_status.has_failures:
+            click.echo("✅ No CI failures detected, but merge is blocked by repository settings.")
+        return
+
+    if state == "closed":
+        click.echo(f"🚪 {ci_status.target_description} is closed.")
+        return
+
+    if draft:
+        click.echo(f"📝 {ci_status.target_description} is in draft state.")
+        if not ci_status.has_failures:
+            click.echo("✅ No CI failures detected for this draft PR.")
+        return
+
+    # Handle unknown mergeable state
+    if mergeable is None and mergeable_state == "unknown":
+        click.echo(f"❓ {ci_status.target_description} merge status is still being computed.")
+        click.echo(
+            "💡 GitHub is still calculating merge conflicts. Please wait a moment and try again."
+        )
+        return
+
+
 def _display_failed_jobs_status(fetcher, owner, repo_name, ci_status):
     """Display failed jobs status with step details."""
     click.echo(

cimonitor/fetcher.py

@@ -201,6 +201,30 @@ def get_pr_head_sha(self, owner: str, repo: str, pr_number: int) -> str:
         except requests.RequestException as e:
             raise ValueError(f"Failed to get PR {pr_number} head SHA: {e}")
 
+    def get_pr_merge_status(self, owner: str, repo: str, pr_number: int) -> dict[str, Any]:
+        """Get merge status information for a pull request.
+
+        Returns:
+            Dictionary with mergeable, mergeable_state, and other PR status info
+        """
+        url = f"https://api.github.com/repos/{owner}/{repo}/pulls/{pr_number}"
+
+        try:
+            response = requests.get(url, headers=self.headers)
+            response.raise_for_status()
+            pr_data = response.json()
+
+            return {
+                "mergeable": pr_data.get("mergeable"),
+                "mergeable_state": pr_data.get("mergeable_state"),
+                "state": pr_data.get("state"),
+                "draft": pr_data.get("draft", False),
+                "base_ref": pr_data.get("base", {}).get("ref"),
+                "head_ref": pr_data.get("head", {}).get("ref"),
+            }
+        except requests.RequestException as e:
+            raise ValueError(f"Failed to get PR {pr_number} merge status: {e}")
+
     def get_branch_head_sha(self, owner: str, repo: str, branch_name: str) -> str:
         """Get the head commit SHA for a branch."""
         url = f"https://api.github.com/repos/{owner}/{repo}/branches/{branch_name}"

cimonitor/services.py

@@ -20,6 +20,7 @@ def __init__(self, failed_check_runs: list[dict[str, Any]], target_description:
         self.failed_check_runs = failed_check_runs
         self.target_description = target_description
         self.has_failures = len(failed_check_runs) > 0
+        self.merge_conflict_info: dict[str, Any] | None = None
 
 
 class WorkflowStepInfo:
@@ -43,7 +44,12 @@ def __init__(self, name: str, html_url: str, conclusion: str):
 
 
 def get_ci_status(
-    fetcher: GitHubCIFetcher, owner: str, repo_name: str, commit_sha: str, target_description: str
+    fetcher: GitHubCIFetcher,
+    owner: str,
+    repo_name: str,
+    commit_sha: str,
+    target_description: str,
+    pr_number: int | None = None,
 ) -> CIStatusResult:
     """Get CI status for a commit with detailed job information.
 
@@ -53,12 +59,24 @@ def get_ci_status(
         repo_name: Repository name
         commit_sha: Target commit SHA
         target_description: Human-readable description of target
+        pr_number: Pull request number (optional)
 
     Returns:
         CIStatusResult with failed jobs and details
     """
     failed_check_runs = fetcher.find_failed_jobs_in_latest_run(owner, repo_name, commit_sha)
-    return CIStatusResult(failed_check_runs, target_description)
+    result = CIStatusResult(failed_check_runs, target_description)
+
+    # Check for merge conflicts if this is a PR
+    if pr_number:
+        try:
+            merge_status = fetcher.get_pr_merge_status(owner, repo_name, pr_number)
+            result.merge_conflict_info = merge_status
+        except ValueError:
+            # If we can't get merge status, don't fail the whole operation
+            pass
+
+    return result
 
 
 def get_job_details_for_status(

tests/test_cli_refactored.py

@@ -30,7 +30,7 @@ def test_status_command_no_failures(
     """Test status command with no failures."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_get_ci_status.return_value = CIStatusResult([], "test branch")
 
     result = runner.invoke(cli, ["status"])
@@ -50,7 +50,7 @@ def test_status_command_with_failures(
     # Setup mocks
     mock_fetcher = Mock()
     mock_fetcher_class.return_value = mock_fetcher
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
 
     failed_runs = [{"name": "Test Job", "conclusion": "failure", "html_url": "https://example.com"}]
     mock_get_ci_status.return_value = CIStatusResult(failed_runs, "test branch")
@@ -77,7 +77,7 @@ def test_logs_command_no_failures(
     """Test logs command with no failures."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_get_job_logs.return_value = {
         "type": "filtered_logs",
         "target_description": "test branch",
@@ -100,7 +100,7 @@ def test_logs_command_with_specific_job(
     """Test logs command with specific job ID."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_get_job_logs.return_value = {
         "type": "specific_job",
         "job_info": {
@@ -127,7 +127,7 @@ def test_logs_command_raw(mock_get_job_logs, mock_get_target_info, mock_fetcher_
     """Test logs command with raw flag."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_get_job_logs.return_value = {
         "type": "raw_logs",
         "failed_jobs": [{"job": {"name": "Test Job", "id": 123}, "logs": "raw log content"}],
@@ -149,7 +149,7 @@ def test_logs_command_filtered(mock_get_job_logs, mock_get_target_info, mock_fet
     """Test logs command with filtered output."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_get_job_logs.return_value = {
         "type": "filtered_logs",
         "target_description": "test branch",
@@ -196,7 +196,7 @@ def test_watch_command_success(
     """Test watch command with successful completion."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_watch_ci_status.return_value = {
         "status": "success",
         "continue_watching": False,
@@ -220,7 +220,7 @@ def test_watch_command_failure(
     """Test watch command with failure."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
     mock_watch_ci_status.return_value = {
         "status": "failed",
         "continue_watching": False,
@@ -243,7 +243,7 @@ def test_watch_command_initial_wait_for_no_runs(
     """Test watch command waits 10 seconds on initial 'no_runs' status."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
 
     # First call returns no_runs, second call (after wait) returns success
     mock_watch_ci_status.side_effect = [
@@ -279,7 +279,7 @@ def test_watch_command_no_runs_after_wait(
     """Test watch command shows proper message when no runs found after initial wait."""
     # Setup mocks
     mock_fetcher_class.return_value = Mock()
-    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch")
+    mock_get_target_info.return_value = ("owner", "repo", "abc123", "test branch", None)
 
     # Both calls return no_runs (persists after wait)
     mock_watch_ci_status.return_value = {