Merge pull request #5 from PennockTech/claude/split-ci-workflow-iKwid

Refactor CI/CD workflows with smart change detection

Author: philpennock

.github/scripts/detect-changes.py

@@ -0,0 +1,217 @@
+#!/usr/bin/env python3
+"""Detect which CI job categories need to run based on changed files.
+
+For pull requests, compares against the PR base SHA.
+For pushes to main, finds the last successful CI run that is an ancestor of
+the current commit, ensuring force-pushes don't mask broken state.
+
+Outputs GitHub Actions outputs: go, goreleaser, markdown, workflows
+Each is 'true' or 'false'.
+"""
+
+import json
+import os
+import subprocess
+import sys
+
+
+def run(cmd, *, check=True, capture=True):
+    """Run a command, return stdout stripped."""
+    r = subprocess.run(
+        cmd,
+        capture_output=capture,
+        text=True,
+        check=check,
+    )
+    return r.stdout.strip() if capture else ""
+
+
+def gh_api(endpoint):
+    """Call the GitHub API via gh CLI, return parsed JSON."""
+    result = subprocess.run(
+        ["gh", "api", endpoint],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+    return json.loads(result.stdout)
+
+
+def is_ancestor(ancestor, descendant):
+    """Check if ancestor is an ancestor of descendant in git history."""
+    r = subprocess.run(
+        ["git", "merge-base", "--is-ancestor", ancestor, descendant],
+        capture_output=True,
+    )
+    return r.returncode == 0
+
+
+def find_last_green_ancestor(repo, workflow_file, head_sha):
+    """Find the most recent successful CI run whose SHA is an ancestor of HEAD.
+
+    Walks backwards through successful runs (up to 10 pages) to find one
+    whose head_sha is a git ancestor of the current commit.  This handles
+    force-pushes correctly: if main was reset, the old "green" commit is
+    no longer an ancestor so we skip it.
+    """
+    for page in range(1, 11):
+        endpoint = (
+            f"repos/{repo}/actions/workflows/{workflow_file}"
+            f"/runs?branch=main&status=success&per_page=10&page={page}"
+        )
+        try:
+            data = gh_api(endpoint)
+        except subprocess.CalledProcessError:
+            print("::warning::Failed to query GitHub API for last successful run", file=sys.stderr)
+            return None
+
+        runs = data.get("workflow_runs", [])
+        if not runs:
+            break
+
+        for run_info in runs:
+            candidate = run_info["head_sha"]
+            if is_ancestor(candidate, head_sha):
+                return candidate
+
+    return None
+
+
+def categorize_files(changed_files):
+    """Categorize changed files into job categories."""
+    categories = {
+        "go": False,
+        "goreleaser": False,
+        "markdown": False,
+        "workflows": False,
+    }
+
+    for f in changed_files:
+        if f.endswith(".go") or f in ("go.mod", "go.sum"):
+            categories["go"] = True
+        if f == "Taskfile.yml":
+            # Taskfile affects all build/test commands
+            categories["go"] = True
+            categories["goreleaser"] = True
+        if f == "goreleaser.yaml":
+            categories["goreleaser"] = True
+            # goreleaser builds Go, so test Go too
+            categories["go"] = True
+        if f.endswith(".md"):
+            categories["markdown"] = True
+        if f.startswith(".github/"):
+            categories["workflows"] = True
+
+    return categories
+
+
+def get_changed_files(base_sha, head_sha):
+    """Get list of files changed between two commits."""
+    try:
+        output = run(["git", "diff", "--name-only", f"{base_sha}...{head_sha}"])
+        return [f for f in output.splitlines() if f]
+    except subprocess.CalledProcessError:
+        # If three-dot diff fails (e.g., shallow clone), try two-dot
+        try:
+            output = run(["git", "diff", "--name-only", f"{base_sha}..{head_sha}"])
+            return [f for f in output.splitlines() if f]
+        except subprocess.CalledProcessError:
+            return None
+
+
+def apply_force_overrides(categories):
+    """Apply workflow_dispatch force overrides (additive only).
+
+    FORCE_ALL=true enables every category.
+    FORCE_<CATEGORY>=true enables that specific category.
+    These can never disable a check that change detection enabled.
+    """
+    if os.environ.get("FORCE_ALL", "").lower() == "true":
+        print("Force override: all checks enabled", file=sys.stderr)
+        for k in categories:
+            categories[k] = True
+        return
+
+    force_map = {
+        "FORCE_GO": "go",
+        "FORCE_GORELEASER": "goreleaser",
+        "FORCE_MARKDOWN": "markdown",
+        "FORCE_WORKFLOWS": "workflows",
+    }
+    for env_var, category in force_map.items():
+        if os.environ.get(env_var, "").lower() == "true":
+            if not categories[category]:
+                print(f"Force override: {category} enabled", file=sys.stderr)
+            categories[category] = True
+
+
+def write_outputs(categories):
+    """Write category flags to GITHUB_OUTPUT."""
+    output_file = os.environ.get("GITHUB_OUTPUT")
+    if output_file:
+        with open(output_file, "a") as f:
+            for key, value in categories.items():
+                f.write(f"{key}={'true' if value else 'false'}\n")
+    # Always print to stderr for logging
+    for key, value in categories.items():
+        print(f"  {key}: {value}", file=sys.stderr)
+
+
+def main():
+    event_name = os.environ.get("GITHUB_EVENT_NAME", "")
+    repo = os.environ.get("GITHUB_REPOSITORY", "")
+    head_sha = os.environ.get("GITHUB_SHA", "")
+
+    # Workflow filename for API queries (must match the actual file)
+    workflow_file = "ci.yaml"
+
+    print(f"Event: {event_name}", file=sys.stderr)
+    print(f"Repository: {repo}", file=sys.stderr)
+    print(f"HEAD SHA: {head_sha}", file=sys.stderr)
+
+    base_sha = None
+
+    if event_name == "pull_request":
+        # For PRs, use the base branch SHA
+        event_path = os.environ.get("GITHUB_EVENT_PATH", "")
+        if event_path:
+            with open(event_path) as f:
+                event_data = json.load(f)
+            base_sha = event_data.get("pull_request", {}).get("base", {}).get("sha")
+        print(f"PR base SHA: {base_sha}", file=sys.stderr)
+
+    elif event_name == "push":
+        # For pushes to main, find the last green ancestor
+        print("Finding last successful CI run that is an ancestor...", file=sys.stderr)
+        base_sha = find_last_green_ancestor(repo, workflow_file, head_sha)
+        if base_sha:
+            print(f"Last green ancestor: {base_sha}", file=sys.stderr)
+        else:
+            print("No green ancestor found", file=sys.stderr)
+
+    # Determine categories from change detection
+    if not base_sha:
+        print("No base SHA available -- running all checks", file=sys.stderr)
+        categories = {k: True for k in ("go", "goreleaser", "markdown", "workflows")}
+    else:
+        changed_files = get_changed_files(base_sha, head_sha)
+        if changed_files is None:
+            print("::warning::git diff failed -- running all checks", file=sys.stderr)
+            categories = {k: True for k in ("go", "goreleaser", "markdown", "workflows")}
+        elif not changed_files:
+            print("No files changed", file=sys.stderr)
+            categories = {k: False for k in ("go", "goreleaser", "markdown", "workflows")}
+        else:
+            print(f"Changed files ({len(changed_files)}):", file=sys.stderr)
+            for f in changed_files:
+                print(f"  {f}", file=sys.stderr)
+            categories = categorize_files(changed_files)
+
+    # Apply workflow_dispatch force overrides (additive only)
+    apply_force_overrides(categories)
+
+    write_outputs(categories)
+
+
+if __name__ == "__main__":
+    main()