[ci] Add tests for PR linter

ci/scripts/check_pr.py

@@ -18,6 +18,7 @@
 import argparse
 import re
 import os
+import json
 import textwrap
 from dataclasses import dataclass
 from typing import Any, List, Callable
@@ -108,10 +109,7 @@ def run_checks(checks: List[Check], s: str, name: str) -> bool:
     parser.add_argument("--pr", required=True)
     parser.add_argument("--remote", default="origin", help="ssh remote to parse")
     parser.add_argument(
-        "--pr-body", help="(testing) PR body to use instead of fetching from GitHub"
-    )
-    parser.add_argument(
-        "--pr-title", help="(testing) PR title to use instead of fetching from GitHub"
+        "--pr-data", help="(testing) PR data to use instead of fetching from GitHub"
     )
     args = parser.parse_args()
 
@@ -121,20 +119,17 @@ def run_checks(checks: List[Check], s: str, name: str) -> bool:
         print(f"PR was not a number: {args.pr}")
         exit(0)
 
-    if args.pr_body:
-        body = args.pr_body
-        title = args.pr_title
+    if args.pr_data:
+        pr = json.loads(args.pr_data)
     else:
         remote = git(["config", "--get", f"remote.{args.remote}.url"])
         user, repo = parse_remote(remote)
 
         github = GitHubRepo(token=os.environ["GITHUB_TOKEN"], user=user, repo=repo)
         pr = github.get(f"pulls/{args.pr}")
-        body = pr["body"]
-        title = pr["title"]
 
-    body = body.strip()
-    title = title.strip()
+    body = "" if pr["body"] is None else pr["body"].strip()
+    title = "" if pr["title"] is None else pr["title"].strip()
 
     title_passed = run_checks(checks=title_checks, s=title, name="PR title")
     print("")

tests/python/ci/test_ci.py

@@ -1144,5 +1144,48 @@ def test_should_rebuild_docker(tmpdir_factory, changed_files, name, check, expec
     assert proc.returncode == expected_code
 
 
+@parameterize_named(
+    passing=dict(
+        title="[something] a change",
+        body="something",
+        expected="All checks passed",
+        expected_code=0,
+    ),
+    period=dict(
+        title="[something] a change.",
+        body="something",
+        expected="trailing_period: FAILED",
+        expected_code=1,
+    ),
+    empty_body=dict(
+        title="[something] a change",
+        body=None,
+        expected="non_empty: FAILED",
+        expected_code=1,
+    ),
+)
+def test_pr_linter(title, body, expected, expected_code):
+    """
+    Test the PR linter
+    """
+    tag_script = REPO_ROOT / "ci" / "scripts" / "check_pr.py"
+    pr_data = {
+        "title": title,
+        "body": body,
+    }
+    proc = run_script(
+        [
+            tag_script,
+            "--pr",
+            1234,
+            "--pr-data",
+            json.dumps(pr_data),
+        ],
+        check=False,
+    )
+    assert proc.returncode == expected_code
+    assert_in(expected, proc.stdout)
+
+
 if __name__ == "__main__":
     tvm.testing.main()