Merge pull request #18423 from ganesh-k13/enh_lint

ENH: Lint checks for PR diffs

1 files changed, 71 insertions, 0 deletions

diff --git a/tools/linter.py b/tools/linter.py
new file mode 100644
index 000000000..2952e91ed
--- /dev/null
+++ b/tools/linter.py
@@ -0,0 +1,71 @@
+import os
+import sys
+import subprocess
+from argparse import ArgumentParser
+from git import Repo, exc
+
+CONFIG = os.path.join(
+         os.path.abspath(os.path.dirname(__file__)),
+         'lint_diff.ini',
+)
+
+
+class DiffLinter:
+    def __init__(self, branch):
+        self.branch = branch
+        self.repo = Repo('.')
+        self.head = self.repo.head.commit
+
+    def get_branch_diff(self, uncommitted = False):
+        """
+            Determine the first common ancestor commit.
+            Find diff between branch and FCA commit.
+            Note: if `uncommitted` is set, check only
+                  uncommitted changes
+        """
+        try:
+            commit = self.repo.merge_base(self.branch, self.head)[0]
+        except exc.GitCommandError:
+            print(f"Branch with name `{self.branch}` does not exist")
+            sys.exit(1)
+
+        if uncommitted:
+            diff = self.repo.git.diff(self.head, '--unified=0', '***.py')
+        else:
+            diff = self.repo.git.diff(commit, self.head,
+                   '--unified=0', '***.py')
+        return diff
+
+    def run_pycodestyle(self, diff):
+        """
+            Original Author: Josh Wilson (@person142)
+            Source:
+              https://github.com/scipy/scipy/blob/master/tools/lint_diff.py
+            Run pycodestyle on the given diff.
+        """
+        res = subprocess.run(
+            ['pycodestyle', '--diff', '--config', CONFIG],
+            input=diff,
+            stdout=subprocess.PIPE,
+            encoding='utf-8',
+        )
+        return res.returncode, res.stdout
+
+    def run_lint(self, uncommitted):
+        diff = self.get_branch_diff(uncommitted)
+        retcode, errors = self.run_pycodestyle(diff)
+
+        errors and print(errors)
+
+        sys.exit(retcode)
+
+
+if __name__ == '__main__':
+    parser = ArgumentParser()
+    parser.add_argument("--branch", type=str, default='main',
+                        help="The branch to diff against")
+    parser.add_argument("--uncommitted", action='store_true',
+                        help="Check only uncommitted changes")
+    args = parser.parse_args()
+
+    DiffLinter(args.branch).run_lint(args.uncommitted)