fix enums and tests

Author: tarrinneal

packages/pigeon/lib/swift_generator.dart

@@ -192,14 +192,8 @@ import FlutterMacOS
             });
           } else if (!hostDatatype.isBuiltin &&
               customEnumNames.contains(field.type.baseName)) {
-            indent.writeln('var ${field.name}: $fieldType? = nil');
             indent.writeln(
-                'let enumVal$index = ${_castForceUnwrap(listValue, const TypeDeclaration(baseName: 'Int', isNullable: true), root)}');
-            indent.write('if let ${field.name}RawValue = enumVal$index');
-            indent.addScoped('{', '}', () {
-              indent.writeln(
-                  '${field.name} = $fieldType(rawValue: ${field.name}RawValue)');
-            });
+                'let ${field.name} = ${_castForceUnwrap(listValue, field.type, root)}');
           } else {
             indent.writeln(
                 'let ${field.name} = ${_castForceUnwrap(listValue, field.type, root)} ');
@@ -683,12 +677,15 @@ String _camelCase(String text) {
 }
 
 String _castForceUnwrap(String value, TypeDeclaration type, Root root) {
-  final String forceUnwrap = type.isNullable ? '' : '!';
   final String castUnwrap = type.isNullable ? '?' : '';
   if (isEnum(root, type)) {
     final String nullableConditionPrefix =
-        type.isNullable ? '$value == nil ? nil : ' : '';
-    return '$nullableConditionPrefix${_swiftTypeForDartType(type)}(rawValue: $value as! Int)$forceUnwrap';
+        type.isNullable ? 'nilOrValue(value: $value) != nil ? ' : '';
+    final String nullableConditionSuffix = type.isNullable
+        ? ' : nilOrValue(value: $value) as! ${type.baseName}?'
+        : '';
+
+    return '$nullableConditionPrefix${_swiftTypeForDartType(type)}(rawValue: $value as! Int)$nullableConditionSuffix';
   } else if (type.baseName == 'Object') {
     // Special-cased to avoid warnings about using 'as' with Any.
     return value;

packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift

@@ -142,11 +142,7 @@ struct AllNullableTypes {
     let nullableNestedList = nilOrValue(value: list[10]) as! [[Bool?]?]? 
     let nullableMapWithAnnotations = nilOrValue(value: list[11]) as! [String?: String?]? 
     let nullableMapWithObject = nilOrValue(value: list[12]) as! [String?: Any?]? 
-    var aNullableEnum: AnEnum? = nil
-    let enumVal13 = nilOrValue(value: list[13]) as! Int?
-    if let aNullableEnumRawValue = enumVal13{
-      aNullableEnum = AnEnum(rawValue: aNullableEnumRawValue)
-    }
+    let aNullableEnum = nilOrValue(value: list[13]) != nil ? AnEnum(rawValue: list[13] as! Int) : nilOrValue(value: list[13]) as! AnEnum?
     let aNullableString = nilOrValue(value: list[14]) as! String? 
 
     return AllNullableTypes(

packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift

@@ -142,11 +142,7 @@ struct AllNullableTypes {
     let nullableNestedList = nilOrValue(value: list[10]) as! [[Bool?]?]? 
     let nullableMapWithAnnotations = nilOrValue(value: list[11]) as! [String?: String?]? 
     let nullableMapWithObject = nilOrValue(value: list[12]) as! [String?: Any?]? 
-    var aNullableEnum: AnEnum? = nil
-    let enumVal13 = nilOrValue(value: list[13]) as! Int?
-    if let aNullableEnumRawValue = enumVal13{
-      aNullableEnum = AnEnum(rawValue: aNullableEnumRawValue)
-    }
+    let aNullableEnum = nilOrValue(value: list[13]) != nil ? AnEnum(rawValue: list[13] as! Int) : nilOrValue(value: list[13]) as! AnEnum?
     let aNullableString = nilOrValue(value: list[14]) as! String? 
 
     return AllNullableTypes(

packages/pigeon/test/swift_generator_test.dart

@@ -83,7 +83,7 @@ void main() {
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('enum Foo: Int'));
-    expect(code, contains('let fooArg = Foo(rawValue: args[0] as! Int)!'));
+    expect(code, contains('let fooArg = Foo(rawValue: args[0] as! Int)'));
   });
 
   test('gen one host api', () {
@@ -915,10 +915,7 @@ void main() {
     const SwiftGenerator generator = SwiftGenerator();
     generator.generate(swiftOptions, root, sink);
     final String code = sink.toString();
-    expect(
-        code,
-        contains(
-            'let fooArg = (args[0] is NSNull) ? (nil as Any?) as! Int64? : args[0] as! Int64?'));
+    expect(code, contains('nilOrValue(value: args[0]) as! Int64?'));
   });
 
   test('nullable argument flutter', () {