From d1746525ce892df52d51ec765c2c5ecfe9998eb2 Mon Sep 17 00:00:00 2001
From: Johannes Wienke <jwienke@itemis.com>
Date: Mon, 8 May 2023 10:36:44 +0200
Subject: [PATCH] Ensure only files are passed to ktlint for autofixing

Avoids passing random log output from the ktlint check run to the second
autofix pass of ktlint. Unfortunately, this requires disabling log
output for the check run as ktlint puts logging onto stdout, for
whatever reason.

Fixes: #162
---
 .../pretty_format_kotlin.py                   | 25 ++++++++++++++++---
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/language_formatters_pre_commit_hooks/pretty_format_kotlin.py b/language_formatters_pre_commit_hooks/pretty_format_kotlin.py
index 69fc916..0766582 100644
--- a/language_formatters_pre_commit_hooks/pretty_format_kotlin.py
+++ b/language_formatters_pre_commit_hooks/pretty_format_kotlin.py
@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 import argparse
+import json
+import subprocess  # nosec B404
 import sys
 import typing
 
@@ -65,13 +67,28 @@ def pretty_format_kotlin(argv: typing.Optional[typing.List[str]] = None) -> int:
     # To workaround this limitation we do run ktlint in check mode only,
     # which provides the expected exit status and we run it again in format
     # mode if autofix flag is enabled
-    check_status, check_output = run_command(
-        "java", *jvm_args, "-jar", ktlint_jar, "--log-level", "debug", "--relative", "--", *_fix_paths(args.filenames)
+    #
+    # Logging must be suppressed here as it goes to stdout. This would
+    # interfere with parsing the output JSON.
+    check_result = subprocess.run(  # nosec: B603 B607
+        [
+            "java",
+            *jvm_args,
+            "-jar",
+            ktlint_jar,
+            "--log-level",
+            "none",
+            "--reporter=json",
+            "--relative",
+            "--",
+            *_fix_paths(args.filenames),
+        ],
+        capture_output=True,
     )
 
     not_pretty_formatted_files: typing.Set[str] = set()
-    if check_status != 0:
-        not_pretty_formatted_files.update(line.split(":", 1)[0] for line in check_output.splitlines())
+    if check_result.returncode != 0:
+        not_pretty_formatted_files.update(item["file"] for item in json.loads(check_result.stdout))
 
         if args.autofix:
             print("Running ktlint format on {}".format(not_pretty_formatted_files))