separate test case file + several declarations added

Author: iimironchuk

lint_test/prefer_match_file_name_ignore_extensions/analysis_options.yaml

@@ -0,0 +1,9 @@
+analyzer:
+  plugins:
+    - ../../custom_lint
+
+custom_lint:
+  rules:
+    - prefer_match_file_name:
+      exclude_entity:
+        - extension

lint_test/prefer_match_file_name_ignore_extensions/prefer_match_file_name_ignore_extensions.dart

@@ -0,0 +1,13 @@
+// ignore_for_file: unused_element, unused_field
+
+/// `prefer_match_file_name` rule will be ignored by this extension because of
+/// exclude_entity:
+/// - extension
+/// in analysis_options.yaml
+extension DefaultExtension on String {}
+
+// expect_lint: prefer_match_file_name
+abstract class WrongNamedClass {}
+
+/// Only first public element declaration is checked
+class PreferMatchFileNameIgnoreExtensions {}

lint_test/pubspec.yaml

@@ -9,6 +9,8 @@ dependencies:
   flutter:
     sdk: flutter
 
+  custom_lint: ^0.7.5
+
 dev_dependencies:
   solid_lints:
     path: ../