From 0f19ef946d4365c8fc4964dc1bdac70a7922f8df Mon Sep 17 00:00:00 2001
From: Matan Lurey <matan@lurey.org>
Date: Tue, 14 Nov 2017 19:05:29 -0800
Subject: [PATCH 1/2] Add index operator access to Expression.

---
 CHANGELOG.md                         | 29 ++++++++++++++++++++++++++--
 lib/src/specs/expression.dart        | 13 +++++++++++++
 pubspec.yaml                         |  2 +-
 test/specs/code/expression_test.dart | 29 ++++++++++++++++++++++++++++
 4 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e94ccd7..94019aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,32 @@
-## 2.1.1-dev
+## 2.2.0-dev
 
 * Imports are prefixed with `_i1` rather than `_1` which satisfies the lint
-  `lowercase_with_underscores`.
+  `lowercase_with_underscores`. While not a strictly breaking change you may
+  have to fix/regenerate golden file-like tests. We added documentation that
+  the specific prefix is not considered stable.
+* Added `Expression.index` for accessing the `[]` operator:
+
+```dart
+void main() {
+  test('should emit an index operator', () {
+    expect(
+      refer('bar').index(literalTrue).assignVar('foo').statement,
+      equalsDart('var foo = bar[true];'),
+    );
+}  );
+
+  test('should emit an index operator set', () {
+    expect(
+      refer('bar')
+        .index(literalTrue)
+        .assign(literalFalse)
+        .assignVar('foo')
+        .statement,
+      equalsDart('var foo = bar[true] = false;'),
+    );
+  });
+}
+```
 
 ## 2.1.0
 
diff --git a/lib/src/specs/expression.dart b/lib/src/specs/expression.dart
index c1ae450..50d3ec6 100644
--- a/lib/src/specs/expression.dart
+++ b/lib/src/specs/expression.dart
@@ -45,6 +45,19 @@ abstract class Expression implements Spec {
     return new BinaryExpression._(expression, other, '&&');
   }
 
+  /// Returns accessing the index operator (`[]`) on `this`.
+  Expression index(Expression index) {
+    return new BinaryExpression._(
+      expression,
+      new CodeExpression(new Block.of([
+        const Code('['),
+        index.code,
+        const Code(']'),
+      ])),
+      '',
+    );
+  }
+
   /// This expression preceded by `await`.
   Expression get awaited {
     return new BinaryExpression._(
diff --git a/pubspec.yaml b/pubspec.yaml
index 2407864..0e58701 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: code_builder
-version: 2.1.1-dev
+version: 2.2.0-dev
 description: A fluent API for generating Dart code
 author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/dart-lang/code_builder
diff --git a/test/specs/code/expression_test.dart b/test/specs/code/expression_test.dart
index 3aa724c..72ced05 100644
--- a/test/specs/code/expression_test.dart
+++ b/test/specs/code/expression_test.dart
@@ -266,6 +266,35 @@ void main() {
     );
   });
 
+  test('should emit an index operator', () {
+    expect(
+      refer('bar').index(literalTrue).assignVar('foo').statement,
+      equalsDart('var foo = bar[true];'),
+    );
+  });
+
+  test('should emit an index operator set', () {
+    expect(
+      refer('bar')
+          .index(literalTrue)
+          .assign(literalFalse)
+          .assignVar('foo')
+          .statement,
+      equalsDart('var foo = bar[true] = false;'),
+    );
+  });
+
+  test('should emit a null-aware index operator set', () {
+    expect(
+      refer('bar')
+          .index(literalTrue)
+          .assignNullAware(literalFalse)
+          .assignVar('foo')
+          .statement,
+      equalsDart('var foo = bar[true] ??= false;'),
+    );
+  });
+
   test('should emit assigning to a var', () {
     expect(
       literalTrue.assignVar('foo'),

From 60491982246aba42f488337b4d8eea5f7417cb54 Mon Sep 17 00:00:00 2001
From: Matan Lurey <matan@lurey.org>
Date: Mon, 20 Nov 2017 20:36:43 -0800
Subject: [PATCH 2/2] Address feedback.

---
 test/specs/code/expression_test.dart | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/specs/code/expression_test.dart b/test/specs/code/expression_test.dart
index 72ced05..7cf5845 100644
--- a/test/specs/code/expression_test.dart
+++ b/test/specs/code/expression_test.dart
@@ -268,19 +268,19 @@ void main() {
 
   test('should emit an index operator', () {
     expect(
-      refer('bar').index(literalTrue).assignVar('foo').statement,
-      equalsDart('var foo = bar[true];'),
+      refer('bar').index(literalString('key')).assignVar('foo').statement,
+      equalsDart("var foo = bar['key'];"),
     );
   });
 
   test('should emit an index operator set', () {
     expect(
       refer('bar')
-          .index(literalTrue)
+          .index(literalString('key'))
           .assign(literalFalse)
           .assignVar('foo')
           .statement,
-      equalsDart('var foo = bar[true] = false;'),
+      equalsDart("var foo = bar['key'] = false;"),
     );
   });