Resolve #91 -- Add Github workflow message support for GitHub Actions

Author: codingjoe

relint/__main__.py

@@ -1,12 +1,19 @@
 import argparse
+import os
 import subprocess  # nosec
 import sys
 import warnings
 
 from rich.progress import track
 
 from relint.config import load_config
-from relint.parse import lint_file, match_with_diff_changes, parse_diff, print_culprits
+from relint.parse import (
+    lint_file,
+    match_with_diff_changes,
+    parse_diff,
+    print_culprits,
+    print_github_actions_output,
+)
 
 
 def parse_args(args=None):
@@ -90,7 +97,11 @@ def main(args=None):
         changed_content = parse_diff(output)
         matches = match_with_diff_changes(changed_content, matches)
 
-    exit_code = print_culprits(matches, args)
+    GITHUB_ACTIONS = os.getenv("GITHUB_ACTIONS") == "true"
+    if GITHUB_ACTIONS:
+        exit_code = print_github_actions_output(matches, args)
+    else:
+        exit_code = print_culprits(matches, args)
     exit(exit_code)
 
 

relint/parse.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import collections
+import os
 
 try:
     import regex as re
@@ -93,6 +94,25 @@ def split_diff_content_by_filename(output: str) -> {str: str}:
     return content_by_filename
 
 
+def print_github_actions_output(matches, args):
+    exit_code = 0
+    for filename, test, match, line_number in matches:
+        exit_code = test.error if exit_code == 0 else exit_code
+        start_line_no = match.string[: match.start()].count("\n") + 1
+        end_line_no = match.string[: match.end()].count("\n") + 1
+        col = match.start() - match.string.rfind("\n", 0, match.start())
+        col_end = match.end() - match.string.rfind("\n", 0, match.end())
+
+        print(
+            f"::{'error' if test.error else 'warning'} file={filename},"
+            f"line={start_line_no},endLine={end_line_no},col={col},colEnd={col_end},"
+            f"title={test.name}::{test.hint}".replace(
+                "\n", "%0A"
+            )
+        )
+    return exit_code
+
+
 def print_culprits(matches, args):
     exit_code = 0
     messages = []

tests/test_main.py

@@ -44,6 +44,25 @@ def test_main_execution_with_error(self, capsys, tmpdir, fixture_dir):
         assert "❱ 1 # FIXME do something" in out
         assert exc_info.value.code == 1
 
+    def test_main_execution_with_error__github_workflow_output(
+        self, monkeypatch, capsys, tmpdir, fixture_dir
+    ):
+        monkeypatch.setenv("GITHUB_ACTIONS", "true")
+        with (fixture_dir / ".relint.yml").open() as fs:
+            config = fs.read()
+        tmpdir.join(".relint.yml").write(config)
+        tmpdir.join("dummy.py").write("# FIXME do something")
+        with tmpdir.as_cwd():
+            with pytest.raises(SystemExit) as exc_info:
+                main(["dummy.py"])
+
+        out, _ = capsys.readouterr()
+        assert (
+            "::error file=dummy.py,line=1,endLine=1,col=3,colEnd=8,title=No fixme (warning)::### This is a multiline hint%0AFix it right away!%0A%0AYou can use code blocks too, like Python:%0A%0A"
+            in out
+        )
+        assert exc_info.value.code == 1
+
     @pytest.mark.parametrize("args", [[], ["--summarize"]])
     def test_main_execution_without_hint(self, args, capsys, tmpdir, fixture_dir):
         with (fixture_dir / ".relint.yml").open() as fs: