feat: Added Button assist and two Lints.

packages/masamune_lints/lib/buttons/masamune_button_add_icon.dart

@@ -0,0 +1,70 @@
+part of '/masamune_lints.dart';
+
+class _MasamuneButtonAddIcon extends DartAssist {
+  _MasamuneButtonAddIcon();
+
+  @override
+  void run(
+    CustomLintResolver resolver,
+    ChangeReporter reporter,
+    CustomLintContext context,
+    SourceRange target,
+  ) {
+    context.registry.addInstanceCreationExpression((node) {
+      if (!target.intersects(node.constructorName.sourceRange)) {
+        return;
+      }
+      final createdType = node.constructorName.type.type;
+      if (createdType == null ||
+          !TypeChecker.any(_MaterialButtonType.values.map((e) => e.typeChecker))
+              .isExactlyType(createdType)) {
+        return;
+      }
+      final simpleIdentifier = node.constructorName.name;
+      final supportedIdentifier = simpleIdentifier?.toSupportedIdentifier();
+
+      if (supportedIdentifier != null && supportedIdentifier.hasIcon) {
+        return;
+      }
+      final changeBuilder = reporter.createChangeBuilder(
+        message: "Add icon to button",
+        priority: _kAddOrRemoveIconPriority,
+      );
+
+      changeBuilder.addDartFileEdit((builder) {
+        if (supportedIdentifier == _SupportedIdentifier.tonal) {
+          builder.addSimpleReplacement(
+            node.constructorName.sourceRange,
+            "FilledButton.tonalIcon",
+          );
+        } else {
+          builder.addSimpleInsertion(
+            node.constructorName.sourceRange.end,
+            ".icon",
+          );
+        }
+
+        bool existIcon = false;
+        for (var argument in node.argumentList.arguments) {
+          if (argument is NamedExpression) {
+            if (argument.name.label.name == "child") {
+              builder.addSimpleReplacement(
+                argument.name.sourceRange,
+                "label:",
+              );
+            }
+            if (argument.name.label.name == "icon") {
+              existIcon = true;
+            }
+          }
+        }
+        if (!existIcon) {
+          builder.addSimpleInsertion(
+            node.argumentList.arguments.last.sourceRange.end,
+            ", icon: Icon(Icons.add // TODO: Change icon)",
+          );
+        }
+      });
+    });
+  }
+}

packages/masamune_lints/lib/buttons/masamune_button_convert.dart

@@ -0,0 +1,82 @@
+part of '/masamune_lints.dart';
+
+class _MasamuneButtonConvert extends DartAssist {
+  _MasamuneButtonConvert({
+    required this.targetType,
+  });
+  final _MaterialButtonType targetType;
+  late final baseType = targetType != _MaterialButtonType.filled
+      ? targetType.getBaseType()
+      : null;
+
+  @override
+  void run(
+    CustomLintResolver resolver,
+    ChangeReporter reporter,
+    CustomLintContext context,
+    SourceRange target,
+  ) {
+    context.registry.addInstanceCreationExpression((node) {
+      if (!target.intersects(node.constructorName.sourceRange)) {
+        return;
+      }
+
+      final createdType = node.constructorName.type.type;
+      if (createdType == null ||
+          !(baseType?.isExactlyType(createdType) ?? false)) {
+        return;
+      }
+
+      final simpleIdentifier = node.constructorName.name;
+      final isFilledButton = const TypeChecker.fromName(
+        "FilledButton",
+        packageName: "flutter",
+      ).isExactlyType(createdType);
+      final supportedIdentifier = simpleIdentifier?.toSupportedIdentifier();
+
+      if (isFilledButton) {
+        if (supportedIdentifier?.isTonal ?? false) {
+          if (targetType == _MaterialButtonType.filledTonal) {
+            return;
+          }
+        } else {
+          if (targetType == _MaterialButtonType.filled) {
+            return;
+          }
+        }
+      }
+
+      final changeBuilder = reporter.createChangeBuilder(
+        message: "Convert to ${targetType.buttonName}",
+        priority: targetType.priority,
+      );
+
+      changeBuilder.addDartFileEdit(
+        (builder) {
+          builder.addSimpleReplacement(
+            node.constructorName.sourceRange,
+            targetType.className +
+                _getReplacementIdentifier(supportedIdentifier, targetType),
+          );
+        },
+      );
+    });
+  }
+
+  String _getReplacementIdentifier(
+      _SupportedIdentifier? identifier, _MaterialButtonType targetType) {
+    if (identifier?.hasIcon ?? false) {
+      if (targetType == _MaterialButtonType.filledTonal) {
+        return ".tonalIcon";
+      } else {
+        return ".icon";
+      }
+    } else {
+      if (targetType == _MaterialButtonType.filledTonal) {
+        return ".tonal";
+      } else {
+        return "";
+      }
+    }
+  }
+}

packages/masamune_lints/lib/buttons/masamune_button_remove_icon.dart

@@ -0,0 +1,73 @@
+part of '/masamune_lints.dart';
+
+class _MasamuneButtonRemoveIcon extends DartAssist {
+  _MasamuneButtonRemoveIcon();
+
+  @override
+  void run(
+    CustomLintResolver resolver,
+    ChangeReporter reporter,
+    CustomLintContext context,
+    SourceRange target,
+  ) {
+    context.registry.addInstanceCreationExpression((node) {
+      if (!target.intersects(node.constructorName.sourceRange)) {
+        return;
+      }
+
+      final createdType = node.constructorName.type.type;
+      if (createdType == null ||
+          !TypeChecker.any(_MaterialButtonType.values.map((e) => e.typeChecker))
+              .isExactlyType(createdType)) {
+        return;
+      }
+
+      final simpleIdentifier = node.constructorName.name;
+      final supportedIdentifier = simpleIdentifier?.toSupportedIdentifier();
+
+      if (supportedIdentifier != null && !supportedIdentifier.hasIcon) {
+        return;
+      }
+
+      final changeBuilder = reporter.createChangeBuilder(
+        message: "Remove icon from button",
+        priority: _kAddOrRemoveIconPriority,
+      );
+
+      changeBuilder.addDartFileEdit((builder) {
+        if (supportedIdentifier == _SupportedIdentifier.tonalIcon) {
+          builder.addSimpleReplacement(
+            node.constructorName.sourceRange,
+            "FilledButton.tonal",
+          );
+        } else {
+          builder.addSimpleReplacement(
+            node.constructorName.sourceRange,
+            node.constructorName.type.name2.lexeme,
+          );
+        }
+
+        for (var argument in node.argumentList.arguments) {
+          if (argument is NamedExpression) {
+            if (argument.name.label.name == "label") {
+              builder.addSimpleReplacement(
+                argument.name.sourceRange,
+                "child:",
+              );
+            }
+
+            if (argument.name.label.name == "icon") {
+              builder.addDeletion(
+                SourceRange(
+                  argument.sourceRange.offset,
+                  argument.sourceRange.length +
+                      (argument.endToken.next?.lexeme == "," ? 1 : 0),
+                ),
+              );
+            }
+          }
+        }
+      });
+    });
+  }
+}

packages/masamune_lints/lib/buttons/masamune_button_type.dart

@@ -0,0 +1,117 @@
+part of '/masamune_lints.dart';
+
+const _kConvertToOtherButtonPriority = 27;
+const _kAddOrRemoveIconPriority = 27;
+
+enum _MaterialButtonType {
+  elevated(
+    buttonName: "ElevatedButton",
+    className: "ElevatedButton",
+    priority: _kConvertToOtherButtonPriority,
+    typeChecker: TypeChecker.fromName(
+      "ElevatedButton",
+      packageName: "flutter",
+    ),
+  ),
+  filled(
+    buttonName: "FilledButton",
+    className: "FilledButton",
+    priority: _kConvertToOtherButtonPriority,
+    typeChecker: TypeChecker.fromName(
+      "FilledButton",
+      packageName: "flutter",
+    ),
+  ),
+  filledTonal(
+    buttonName: "FilledTonalButton",
+    className: "FilledButton",
+    priority: _kConvertToOtherButtonPriority,
+    typeChecker: TypeChecker.fromName(
+      "FilledButton",
+      packageName: "flutter",
+    ),
+  ),
+  outlined(
+    buttonName: "OutlinedButton",
+    className: "OutlinedButton",
+    priority: _kConvertToOtherButtonPriority,
+    typeChecker: TypeChecker.fromName(
+      "OutlinedButton",
+      packageName: "flutter",
+    ),
+  ),
+  text(
+    buttonName: "TextButton",
+    className: "TextButton",
+    priority: _kConvertToOtherButtonPriority,
+    typeChecker: TypeChecker.fromName(
+      "TextButton",
+      packageName: "flutter",
+    ),
+  );
+
+  const _MaterialButtonType({
+    required this.buttonName,
+    required this.className,
+    required this.priority,
+    required this.typeChecker,
+  });
+  final String buttonName;
+  final String className;
+  final int priority;
+  final TypeChecker typeChecker;
+
+  TypeChecker getBaseType() {
+    return TypeChecker.any(
+      _MaterialButtonType.values
+          .where((e) => e != this)
+          .map((e) => e.typeChecker),
+    );
+  }
+}
+
+enum _SupportedIdentifier {
+  icon,
+  tonal,
+  tonalIcon;
+
+  bool get isTonal {
+    switch (this) {
+      case _SupportedIdentifier.icon:
+        return false;
+      case _SupportedIdentifier.tonal:
+        return true;
+      case _SupportedIdentifier.tonalIcon:
+        return true;
+      default:
+        return false;
+    }
+  }
+
+  bool get hasIcon {
+    switch (this) {
+      case _SupportedIdentifier.icon:
+        return true;
+      case _SupportedIdentifier.tonal:
+        return false;
+      case _SupportedIdentifier.tonalIcon:
+        return true;
+      default:
+        return false;
+    }
+  }
+}
+
+extension _SimpleIdentifierExtensions on SimpleIdentifier {
+  _SupportedIdentifier? toSupportedIdentifier() {
+    switch (name) {
+      case "icon":
+        return _SupportedIdentifier.icon;
+      case "tonal":
+        return _SupportedIdentifier.tonal;
+      case "tonalIcon":
+        return _SupportedIdentifier.tonalIcon;
+    }
+    return null;
+  }
+}

packages/masamune_lints/lib/common/masamune_limit_if_nesting.dart

@@ -0,0 +1,40 @@
+part of '/masamune_lints.dart';
+
+const _kMaxNestingCount = 3;
+
+class _MasamuneLimitIfNesting extends DartLintRule {
+  const _MasamuneLimitIfNesting()
+      : super(
+          code: _code,
+        );
+
+  static const _code = LintCode(
+    name: "masamune_if_nesting_should_limit",
+    problemMessage:
+        "Nesting hierarchy for if should be limited to $_kMaxNestingCount units. ifのネスト階層は$_kMaxNestingCount個までにしてください。",
+    errorSeverity: ErrorSeverity.WARNING,
+  );
+
+  @override
+  void run(
+    CustomLintResolver resolver,
+    ErrorReporter reporter,
+    CustomLintContext context,
+  ) {
+    context.registry.addIfStatement((node) {
+      int nestingLevel = 0;
+      AstNode? currentNode = node;
+
+      while (currentNode != null) {
+        if (currentNode is IfStatement && currentNode.elseStatement == null) {
+          nestingLevel++;
+        }
+        currentNode = currentNode.parent;
+      }
+
+      if (nestingLevel > _kMaxNestingCount) {
+        reporter.reportErrorForNode(_code, node);
+      }
+    });
+  }
+}