Added custom pre-commit hook

.pre-commit-config.yaml

@@ -61,3 +61,10 @@ repos:
   - repo: meta
     hooks:
       - id: check-useless-excludes
+  - repo: local
+    hooks:
+      - id: check-json-indentation
+        name: Check JSON Indentation Consistency
+        entry: pre-commit/check_json_indentation.py
+        language: python
+        files: \.json$

.pre-commit-hooks.yaml

@@ -0,0 +1,8 @@
+- id: check-json-indentation
+  name: Check JSON Indentation Consistency
+  description: This hook checks that JSON files do not have mixed tabs and spaces for indentation.
+  entry: pre-commit/check_json_indentation.py
+  language: python
+  files: \.json$
+  types: [text]
+  verbose: true

.taskcluster.yml

@@ -48,6 +48,7 @@ tasks:
             - "git clone --quiet ${repository} bugbot &&
               cd bugbot &&
               git -c advice.detachedHead=false checkout ${head_rev} &&
+              chmod +x pre-commit/check_json_indentation.py &&
               pip install --quiet -r requirements-test.txt &&
               pre-commit run --all-files --show-diff-on-failure &&
               tox -e $TOX_ENV &&

pre-commit/check_json_indentation.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+import sys
+
+
+def check_json_indentation(filename):
+    with open(filename, "r") as file:
+        lines = file.readlines()
+
+    tabs_found = False
+    spaces_found = False
+
+    for line in lines:
+        stripped_line = line.lstrip()
+        if stripped_line and line.startswith("\t"):
+            tabs_found = True
+        elif stripped_line and line.startswith(" "):
+            spaces_found = True
+
+        if tabs_found and spaces_found:
+            print(f"Error: {filename} contains mixed tabs and spaces for indentation.")
+            return False
+
+    return True
+
+
+if __name__ == "__main__":
+    files_to_check = sys.argv[1:]
+    exit_code = 0
+
+    for json_file in files_to_check:
+        if not check_json_indentation(json_file):
+            exit_code = 1
+
+    sys.exit(exit_code)