Make pixi build testsuite more flexible (#53)

Author: Hofer-Julian

.github/workflows/prevent-branch-override-merge.yml

@@ -0,0 +1,17 @@
+name: Prevent Branch Override Merge
+
+on:
+  pull_request:
+    branches: [main]
+
+jobs:
+  check-branch-override:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+
+      - name: Set up pixi
+        uses: prefix-dev/setup-pixi@main
+
+      - name: Check for branch override files
+        run: pixi run check-branch-override

README.md

@@ -31,6 +31,25 @@ Also, check out the other Pixi tasks to run more tests on your local machine:
 pixi run test
 ```
 
+## Testing PR combinations in CI
+
+To test a combination of PRs from this testsuite with PRs from [Pixi] or [pixi-build-backends]:
+
+1. Create a `.env.ci` file with the following environment variables:
+   ```shell
+   # Override pixi repository/branch
+   PIXI_CI_REPO_NAME="your-username/pixi"
+   PIXI_CI_REPO_BRANCH="your-feature-branch"
+   
+   # Override build backends repository/branch  
+   BUILD_BACKENDS_CI_REPO_NAME="your-username/pixi-build-backends"
+   BUILD_BACKENDS_CI_REPO_BRANCH="your-feature-branch"
+   ```
+2. The CI will use these overrides when downloading artifacts for testing
+3. **Important**: Remove `.env.ci` before merging to main (CI will prevent merge if present)
+
+This allows you to test how your testsuite changes work with specific branches from the other repositories.
+
 
 [Pixi]: https://github.com/prefix-dev/pixi
 [pixi-build-backends]: https://github.com/prefix-dev/pixi-build-backends

pixi.toml

@@ -40,6 +40,7 @@ test-specific-test = { cmd = "pytest -k '{{ test_substring }}'", args = [
 # Update one test channel by passing on value of `mappings.toml`
 # e.g. "multiple_versions_channel_1"
 build-repos = { cmd = "python scripts/build-repos.py", description = "Update and build external repositories (PIXI and BUILD_BACKENDS)" }
+check-branch-override = { cmd = "python scripts/check-branch-override.py", description = "Check for branch override files that shouldn't be merged" }
 download-artifacts = { cmd = "python scripts/download-artifacts.py" }
 update-lockfiles = { cmd = "python scripts/update-lockfiles.py {{ folder }}", args = [
   { "arg" = "folder", "default" = "" },

scripts/check-branch-override.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+"""
+Script to check for CI override files that shouldn't be merged to main.
+
+This script ensures that .env.ci files used for testing PR combinations
+don't accidentally get merged to the main branch.
+"""
+
+import sys
+from pathlib import Path
+
+
+def main() -> None:
+    """Check if CI override files exist and exit with error if found."""
+    repo_root = Path(__file__).parent.parent
+    override_file = repo_root / ".env.ci"
+
+    if override_file.exists():
+        print("❌ ERROR: .env.ci file detected")
+        print("This file is used for testing PR combinations and should not be merged to main")
+        print("Please remove .env.ci from your branch")
+        sys.exit(1)
+    else:
+        print("✅ No CI override files detected - safe to merge")
+        sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()

scripts/download-artifacts.py

@@ -170,22 +170,28 @@ def get_matching_artifact(
     return None
 
 
+def load_env_files() -> None:
+    """Load both .env and .env.ci files if they exist."""
+    project_root = Path(__file__).parent.parent
+    env_file = project_root / ".env"
+    env_ci_file = project_root / ".env.ci"
+
+    for env in [env_file, env_ci_file]:
+        if env.exists():
+            load_dotenv(env)
+            console.print(f"[green]Loaded environment variables from {env_file}")
+
+
 def download_github_artifact(
     github_token: str | None,
     output_dir: Path,
     repo: str,
     workflow: str,
+    target_branch: str,
     run_id: int | None = None,
 ) -> None:
     # Get current platform
-    if repo == "prefix-dev/pixi":
-        current_platform = get_current_platform()
-        console.print(f"[blue]Detected platform: {current_platform}")
-    elif repo == "prefix-dev/pixi-build-backends":
-        current_platform = get_current_platform()
-        console.print(f"[blue]Detected platform: {current_platform}")
-    else:
-        raise ValueError(f"Unsupported repository: {repo}")
+    current_platform = get_current_platform()
 
     # Initialize GitHub client
     gh = Github(github_token)
@@ -195,9 +201,9 @@ def download_github_artifact(
     console.print(f"[green]Connected to repository: {repository.full_name}")
 
     # Find the artifact for our platform
-    if repo == "prefix-dev/pixi":
+    if repo.endswith("/pixi"):
         artifact_name_pattern = f"pixi-{current_platform}"
-    elif repo == "prefix-dev/pixi-build-backends":
+    elif repo.endswith("/pixi-build-backends"):
         artifact_name_pattern = f"pixi-build-backends-{current_platform}"
     else:
         raise ValueError(f"Unsupported repository: {repo}")
@@ -226,9 +232,9 @@ def download_github_artifact(
 
         console.print(f"[blue]Found workflow: {target_workflow.name}")
 
-        # Get latest workflow run from main branch
-        console.print("[blue]Finding latest workflow run from main branch")
-        runs = target_workflow.get_runs(branch="main", event="push")
+        # Get latest workflow run from target branch
+        console.print(f"[blue]Finding latest workflow run from {target_branch} branch")
+        runs = target_workflow.get_runs(branch=target_branch, event="push")
         # Check the past five runs until a suitable candidate is found
         for selected_run in itertools.islice(runs, 3):
             artifacts = selected_run.get_artifacts()
@@ -260,8 +266,8 @@ def download_github_artifact(
 
 
 def main() -> None:
-    # Load environment variables from .env file
-    load_dotenv()
+    # Load environment files
+    load_env_files()
 
     parser = argparse.ArgumentParser(description="Download artifacts from GitHub Actions")
     parser.add_argument(
@@ -281,13 +287,19 @@ def main() -> None:
 
     args = parser.parse_args()
 
-    # Set repo and workflow based on repository choice
+    # Set repo and workflow based on repository choice, with CI overrides
     if args.repo == "pixi":
-        repo = "prefix-dev/pixi"
+        repo = os.getenv("PIXI_CI_REPO_NAME", "prefix-dev/pixi")
         workflow = "CI"
+        target_branch = os.getenv("PIXI_CI_REPO_BRANCH", "main")
     elif args.repo == "pixi-build-backends":
-        repo = "prefix-dev/pixi-build-backends"
+        repo = os.getenv("BUILD_BACKENDS_CI_REPO_NAME", "prefix-dev/pixi-build-backends")
         workflow = "Testsuite"
+        target_branch = os.getenv("BUILD_BACKENDS_CI_REPO_BRANCH", "main")
+
+    # Show override info if non-default values are being used
+    if target_branch != "main" or repo != f"prefix-dev/{args.repo}":
+        console.print(f"[yellow]CI overrides active: using {repo} branch {target_branch}")
 
     # Hardcode output directory to "artifacts"
     output_dir = Path("artifacts")
@@ -302,7 +314,9 @@ def main() -> None:
         sys.exit()
 
     try:
-        download_github_artifact(github_token, output_dir, repo, workflow, args.run_id)
+        download_github_artifact(
+            github_token, output_dir, repo, workflow, target_branch, args.run_id
+        )
         console.print("[green][SUCCESS] Download completed successfully!")
         sys.exit(0)
     except Exception as e: