Delegate Yaml parsing to be done within the Yaml object

packages/yumemi_lints/lib/src/command_services/update_command_service.dart

@@ -5,6 +5,7 @@ import 'package:yumemi_lints/src/models/exceptions.dart';
 import 'package:yumemi_lints/src/models/exit_status.dart';
 import 'package:yumemi_lints/src/models/project_type.dart';
 import 'package:yumemi_lints/src/models/version.dart';
+import 'package:yumemi_lints/src/models/yaml.dart';
 
 class UpdateCommandService {
   const UpdateCommandService();
@@ -168,8 +169,8 @@ class UpdateCommandService {
   }
 
   Version getFlutterVersion(File pubspecFile) {
-    final yamls = parseYamlToMap(pubspecFile.readAsStringSync());
-    final environment = yamls['environment'] as Map<String, dynamic>;
+    final yaml = Yaml.parse(pubspecFile);
+    final environment = yaml.yamlMap['environment'] as Map<String, dynamic>;
     final flutterVersion = environment['flutter'] as String?;
 
     if (flutterVersion == null) {
@@ -182,62 +183,9 @@ class UpdateCommandService {
     return Version.parse(flutterVersion);
   }
 
-  Map<String, dynamic> parseYamlToMap(String yaml) {
-    final lines = yaml.split('\n');
-    final result = <String, dynamic>{};
-    final stack = <String>[];
-    var current = result;
-
-    for (final line in lines) {
-      final trimmed = line.trim();
-      if (trimmed.isEmpty || trimmed.startsWith('#')) {
-        continue;
-      }
-
-      // Get parent element if there is an indent.
-      final indent = line.length - line.trimLeft().length;
-      while (stack.length > indent) {
-        stack.removeLast();
-        current = stack.isEmpty
-            ? result
-            : current['__parent__'] as Map<String, dynamic>;
-      }
-
-      if (trimmed.contains(':')) {
-        final parts = trimmed.split(':');
-        final key = parts[0].trim();
-        final value = parts.sublist(1).join(':').trim();
-        final newMap = <String, dynamic>{};
-        // If value is empty,
-        // create a new Map assuming a child element and add it to current.
-        if (value.isEmpty) {
-          current[key] = newMap;
-          newMap['__parent__'] = current;
-          stack.add(key);
-          current = newMap;
-        } else {
-          current[key] = value;
-        }
-      }
-    }
-
-    _cleanParent(result);
-    return result;
-  }
-
-  // Delete the "__parent__" key.
-  void _cleanParent(Map<String, dynamic> map) {
-    map.remove('__parent__');
-    for (final value in map.values) {
-      if (value is Map<String, dynamic>) {
-        _cleanParent(value);
-      }
-    }
-  }
-
   Version getDartVersion(File pubspecFile) {
-    final yamls = parseYamlToMap(pubspecFile.readAsStringSync());
-    final environment = yamls['environment'] as Map<String, dynamic>;
+    final yaml = Yaml.parse(pubspecFile);
+    final environment = yaml.yamlMap['environment'] as Map<String, dynamic>;
     final dartVersion = environment['flutter'] as String?;
 
     if (dartVersion == null) {

packages/yumemi_lints/lib/src/models/yaml.dart

@@ -0,0 +1,63 @@
+import 'dart:io';
+
+class Yaml {
+  const Yaml._(this.yamlMap);
+
+  // Convert and parse the file system into a Yaml file,
+  // obtain a YamlMap, and then create a Yaml object.
+  factory Yaml.parse(File file) {
+    final lines = file.readAsStringSync().split('\n');
+    final result = <String, dynamic>{};
+    final stack = <String>[];
+    var current = result;
+
+    for (final line in lines) {
+      final trimmed = line.trim();
+      if (trimmed.isEmpty || trimmed.startsWith('#')) {
+        continue;
+      }
+
+      // Get parent element if there is an indent.
+      final indent = line.length - line.trimLeft().length;
+      while (stack.length > indent) {
+        stack.removeLast();
+        current = stack.isEmpty
+            ? result
+            : current['__parent__'] as Map<String, dynamic>;
+      }
+
+      if (trimmed.contains(':')) {
+        final parts = trimmed.split(':');
+        final key = parts[0].trim();
+        final value = parts.sublist(1).join(':').trim();
+        final newMap = <String, dynamic>{};
+        // If value is empty,
+        // create a new Map assuming a child element and add it to current.
+        if (value.isEmpty) {
+          current[key] = newMap;
+          newMap['__parent__'] = current;
+          stack.add(key);
+          current = newMap;
+        } else {
+          current[key] = value;
+        }
+      }
+    }
+    // Delete the "__parent__" key.
+    void cleanParent(Map<String, dynamic> map) {
+      map.remove('__parent__');
+      for (final value in map.values) {
+        if (value is Map<String, dynamic>) {
+          cleanParent(value);
+        }
+      }
+    }
+
+    cleanParent(result);
+    return Yaml._(result);
+  }
+
+  final YamlMap yamlMap;
+}
+
+typedef YamlMap = Map<String, dynamic>;