build(coverage): add comment to PR with diff-cover output

- add script to help format the coverage comment
- manage steps logic

refs #15

script/actions_utils/coverage.sh

@@ -0,0 +1,19 @@
+CURR_DIR=`dirname $0`
+
+# Run diff-coverage
+poetry run diff-cover coverage.xml --fail-under 100 \
+--html-report coverage.html \
+--compare-branch origin/"$1" | tee diff-coverage.txt
+
+# Get exit code without closing the script
+TEST_EXIT_CODE="$?"
+
+# Format diff-coverage.txt for PR comment
+poetry run python script/actions_utils/coverage_report_format.py \
+--diff-cover-exit-code "$TEST_EXIT_CODE" \
+--diff-cover-output diff-coverage.txt
+
+# Set exit code if test failed
+if [[ "$TEST_EXIT_CODE" != "0" ]]; then
+    exit "$TEST_EXIT_CODE"
+fi

script/actions_utils/coverage_report_format.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+
+"""Helper script for github actions"""
+import argparse
+import traceback
+from pathlib import Path
+
+
+def main(args):
+    """Entry point"""
+    diff_cover_file_path = Path(args.diff_cover_output).resolve().absolute()
+
+    diff_cover_content = None
+
+    with open(diff_cover_file_path, "r") as f:
+        diff_cover_content = f.readlines()
+
+    with open(diff_cover_file_path, "w", encoding="utf-8") as f:
+        if args.diff_cover_exit_code == 0:
+            f.write("## Coverage passed ✅\n\n")
+        else:
+            f.write("## Coverage failed ❌\n\n")
+
+        # Open collapsible section
+        f.write("<details><summary>Coverage details</summary>\n<p>\n\n")
+        f.write("```\n")
+
+        f.writelines(diff_cover_content)
+
+        # Close collapsible section
+        f.write("```\n\n")
+        f.write("</p>\n</details>\n\n")
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(allow_abbrev=False)
+
+    parser.add_argument("--diff-cover-exit-code", type=int, required=True)
+    parser.add_argument("--diff-cover-output", type=str, required=True)
+
+    cli_args = parser.parse_args()
+    try:
+        main(cli_args)
+    except Exception as e:
+        traceback.print_exc()