Refactor calculate-job-matrix.py

src/ci/github-actions/calculate-job-matrix.py

@@ -9,12 +9,12 @@ and filters them based on the event that happened on CI.
 
 Currently, it only supports PR and try builds.
 """
-
+import enum
 import json
+import logging
 import os
-import sys
 from pathlib import Path
-from typing import List, Dict
+from typing import List, Dict, Any, Optional
 
 import yaml
 
@@ -27,16 +27,19 @@ def name_jobs(jobs: List[Dict], prefix: str) -> List[Dict]:
     return jobs
 
 
-if __name__ == "__main__":
-    github_ctx = json.loads(os.environ["GITHUB_CTX"])
+class JobType(enum.Enum):
+    PR = enum.auto()
+    Try = enum.auto()
 
-    with open(JOBS_YAML_PATH) as f:
-        data = yaml.safe_load(f)
 
+def find_job_type(github_ctx: Dict[str, Any]) -> Optional[JobType]:
     event_name = github_ctx["event_name"]
     ref = github_ctx["ref"]
     repository = github_ctx["repository"]
 
+    if event_name == "pull_request":
+        return JobType.PR
+    elif event_name == "push":
         old_bors_try_build = (
             ref in ("refs/heads/try", "refs/heads/try-perf") and
             repository == "rust-lang-ci/rust"
@@ -47,13 +50,35 @@ if __name__ == "__main__":
         )
         try_build = old_bors_try_build or new_bors_try_build
 
-    jobs = []
-    # Pull request CI jobs. Their name is 'PR - <image>'
-    if event_name == "pull_request":
-        jobs = name_jobs(data["pr"], "PR")
-    # Try builds
-    elif event_name == "push" and try_build:
-        jobs = name_jobs(data["try"], "try")
+        if try_build:
+            return JobType.Try
 
-    print(f"Output:\n{json.dumps(jobs, indent=4)}", file=sys.stderr)
+    return None
+
+
+def calculate_jobs(job_type: JobType, job_data: Dict[str, Any]) -> List[Dict[str, Any]]:
+    if job_type == JobType.PR:
+        return name_jobs(job_data["pr"], "PR")
+    elif job_type == JobType.Try:
+        return name_jobs(job_data["try"], "try")
+
+    return []
+
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.INFO)
+
+    github_ctx = json.loads(os.environ["GITHUB_CTX"])
+
+    with open(JOBS_YAML_PATH) as f:
+        data = yaml.safe_load(f)
+
+    job_type = find_job_type(github_ctx)
+    logging.info(f"Job type: {job_type}")
+
+    jobs = []
+    if job_type is not None:
+        jobs = calculate_jobs(job_type, data)
+
+    logging.info(f"Output:\n{yaml.dump(jobs, indent=4)}")
     print(f"jobs={json.dumps(jobs)}")