Add Expression.parenthesized

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * Add support for named arguments in `enum` classes
 * Add support for external keyword on fields.
+* Add `Expression.parenthesized` to manually wrap an expression in parenthesis.
 
 ## 4.5.0
 

lib/code_builder.dart

@@ -25,6 +25,7 @@ export 'src/specs/expression.dart'
         InvokeExpressionType,
         LiteralExpression,
         LiteralListExpression,
+        ParenthesizedExpression,
         ToCodeExpression,
         declareConst,
         declareFinal,

lib/src/specs/expression.dart

@@ -331,6 +331,9 @@ abstract class Expression implements Spec {
   /// May be overridden to support other types implementing [Expression].
   @visibleForOverriding
   Expression get expression => this;
+
+  /// Returns this expression wrapped in parenthesis.
+  ParenthesizedExpression get parenthesized => ParenthesizedExpression._(this);
 }
 
 /// Declare a const variable named [variableName].

test/specs/code/expression_test.dart

@@ -731,4 +731,13 @@ void main() {
             .assign(refer('bar')),
         equalsDart('late String foo = bar'));
   });
+
+  test('should emit a perenthesized epression', () {
+    expect(
+        refer('foo').ifNullThen(refer('FormatException')
+            .newInstance([literalString('missing foo')])
+            .thrown
+            .parenthesized),
+        equalsDart('foo ?? (throw FormatException(\'missing foo\'))'));
+  });
 }