Address comments.

Address comments and presubmit script.

.

.travis.yml

@@ -4,4 +4,4 @@ dart:
   - dev
   - stable
 
-script: ./tool/travis.sh
+script: ./tool/presubmit.sh

README.md

@@ -40,7 +40,7 @@ var clazz = new ClassBuilder('Animal', asExtends: base);
 clazz.addMethod(
   new MethodBuilder.returnVoid(
     'eat',
-    returns: reference('print).call([literal('Yum')]),
+    returns: reference('print').call([literal('Yum')]),
   ),
 );
 ```

lib/code_builder.dart

@@ -2,9 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:dart_style/dart_style.dart';
-import 'package:meta/meta.dart';
-
 export 'src/builders/annotation.dart' show AnnotationBuilder;
 export 'src/builders/class.dart'
     show asStatic, clazz, extend, implement, mixin, ClassBuilder;
@@ -34,15 +31,3 @@ export 'src/builders/shared.dart' show AstBuilder, Scope;
 export 'src/builders/statement.dart'
     show ifThen, elseIf, elseThen, IfStatementBuilder, StatementBuilder;
 export 'src/builders/type.dart' show NewInstanceBuilder, TypeBuilder;
-
-final _dartFmt = new DartFormatter();
-
-/// Returns [source] formatted by `dartfmt`.
-@visibleForTesting
-String dartfmt(String source) {
-  try {
-    return _dartFmt.format(source);
-  } on FormatterException catch (_) {
-    return _dartFmt.formatStatement(source);
-  }
-}

lib/dart/async.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-/// Contains reference to the `dart:async` SDK for use in code generation.
+/// Contains references to the `dart:async` SDK for use in code generation.
 ///
 /// This library is currently *experimental*, and is subject to change; it is
 /// currently manually maintained but there might be a strong use case for this
@@ -14,11 +14,11 @@
 ///     import 'package:code_builder/code_builder.dart';
 ///     import 'package:code_builder/dart/async.dart';
 ///
-/// All references are _namespaced_ under [async]. Try it:
+/// All references are _namespaced_ under [lib$async]. Try it:
 ///     // Outputs: new Future.value('Hello')
 ///     async.Future.newInstanceNamed('value', [literal('Hello')]);
 ///
-/// If you are [missing a reference from `dart:async`](https://goo.gl/XbSfmT)
+/// If you are [missing a symbol from `dart:async`](https://goo.gl/XbSfmT)
 /// please send us a [pull request](https://goo.gl/2LvV7f) or
 /// [file an issue](https://goo.gl/IooPfl).
 library code_builder.dart.async;
@@ -27,10 +27,10 @@ import 'dart:async' as dart_async;
 
 import 'package:code_builder/code_builder.dart';
 
-/// A namespace for references in `dart:async`.
-final DartAsync async = new DartAsync._();
+/// References to `dart:async`.
+final DartAsync lib$async = new DartAsync._();
 
-/// References to the `dart:async` library for code generation. See [async].
+/// References to the `dart:async` library for code generation. See [lib$async].
 class DartAsync {
   /// References [dart_async.Future].
   final ReferenceBuilder Future = _ref('Future');

lib/dart/core.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-/// Contains reference to the `dart:core` SDK for use in code generation.
+/// Contains references to the `dart:core` SDK for use in code generation.
 ///
 /// This library is currently *experimental*, and is subject to change; it is
 /// currently manually maintained but there might be a strong use case for this
@@ -14,7 +14,7 @@
 ///     import 'package:code_builder/code_builder.dart';
 ///     import 'package:code_builder/dart/core.dart';
 ///
-/// All references are _namespaced_ under [core]. Try it:
+/// All references are _namespaced_ under [lib$core]. Try it:
 ///     // Outputs: print('Hello World')
 ///     core.print.call([literal('Hello World')]);
 ///
@@ -28,9 +28,9 @@ import 'dart:core' as dart_core;
 import 'package:code_builder/code_builder.dart';
 
 /// A namespace for references in `dart:core`.
-final DartCore core = new DartCore._();
+final DartCore lib$core = new DartCore._();
 
-/// References to the `dart:core` library for code generation. See [core].
+/// References to the `dart:core` library for code generation. See [lib$core].
 class DartCore {
   /// References [dart_core.bool].
   final ReferenceBuilder bool = _ref('bool');

lib/src/builders/annotation.dart

@@ -7,7 +7,7 @@ import 'package:code_builder/src/builders/class.dart';
 import 'package:code_builder/src/builders/parameter.dart';
 import 'package:code_builder/src/builders/shared.dart';
 
-/// Lazily builds an [Annotation] AST when [buildAnnotation] is invoked.
+/// Builds an [Annotation] AST when [buildAnnotation] is invoked.
 abstract class AnnotationBuilder
     implements ValidClassMember, ValidParameterMember {
   /// Returns an [Annotation] AST representing the builder.
@@ -43,7 +43,7 @@ abstract class HasAnnotationsMixin implements HasAnnotations {
       .toList();
 
   /// Clones all annotations to [clone].
-  void cloneAnnotationsTo(HasAnnotations clone) {
+  void copyAnnotationsTo(HasAnnotations clone) {
     clone.addAnnotations(_annotations);
   }
 }

lib/src/builders/class.dart

@@ -49,7 +49,7 @@ ClassBuilder clazz(
 }
 
 /// Wrap [member] to be emitted as a `static` method or field.
-_StaticFieldWrapper asStatic(ValidClassMember member) {
+ValidClassMember asStatic(ValidClassMember member) {
   return new _StaticFieldWrapper(member);
 }
 
@@ -198,7 +198,7 @@ class _ClassBuilderImpl extends Object
   ClassDeclaration buildClass([Scope scope]) {
     var extend = _extends;
     if (extend == null && _with.isNotEmpty) {
-      extend = core.Object;
+      extend = lib$core.Object;
     }
     final clazz = new ClassDeclaration(
       null,

lib/src/builders/expression.dart

@@ -109,7 +109,11 @@ abstract class AbstractExpressionMixin implements ExpressionBuilder {
   StatementBuilder asAssert() => new _AsAssert(this);
 
   @override
-  StatementBuilder asAssign(String variable) => new _AsAssign(this, variable);
+  StatementBuilder asAssign(
+    String variable, {
+    bool nullAware: false,
+  }) =>
+      new _AsAssign(this, variable, nullAware);
 
   @override
   StatementBuilder asConst(String variable, [TypeBuilder type]) {
@@ -162,7 +166,7 @@ abstract class AbstractExpressionMixin implements ExpressionBuilder {
 
   @override
   ExpressionBuilder identical(ExpressionBuilder other) {
-    return core.identical.call([
+    return lib$core.identical.call([
       this,
       other,
     ]);
@@ -183,6 +187,9 @@ abstract class AbstractExpressionMixin implements ExpressionBuilder {
   @override
   ExpressionBuilder negate() => new _NegateExpression(this);
 
+  @override
+  ExpressionBuilder negative() => new _NegativeExpression(this);
+
   @override
   ExpressionBuilder notEquals(ExpressionBuilder other) {
     return new _AsBinaryExpression(
@@ -196,7 +203,7 @@ abstract class AbstractExpressionMixin implements ExpressionBuilder {
   ExpressionBuilder parentheses() => new _ParenthesesExpression(this);
 }
 
-/// Lazily builds an [Expression] AST when [buildExpression] is invoked.
+/// Builds an [Expression] AST when [buildExpression] is invoked.
 abstract class ExpressionBuilder
     implements AstBuilder, StatementBuilder, ValidParameterMember {
   /// Returns as an [ExpressionBuilder] multiplying by [other].
@@ -266,6 +273,9 @@ abstract class ExpressionBuilder
   /// Returns as an [ExpressionBuilder] negating using the `!` operator.
   ExpressionBuilder negate();
 
+  /// Returns as an [ExpressionBuilder] negating the value,
+  ExpressionBuilder negative();
+
   /// Returns as an [ExpressionBuilder] comparing using `!=` against [other].
   ExpressionBuilder notEquals(ExpressionBuilder other);
 

lib/src/builders/expression/assign.dart

@@ -1,10 +1,11 @@
 part of code_builder.src.builders.expression;
 
 class _AsAssign extends AbstractExpressionMixin {
-  final ExpressionBuilder _value;
   final String _name;
+  final bool _nullAware;
+  final ExpressionBuilder _value;
 
-  _AsAssign(this._value, this._name);
+  _AsAssign(this._value, this._name, this._nullAware);
 
   @override
   AstNode buildAst([Scope scope]) => buildExpression(scope);
@@ -13,7 +14,7 @@ class _AsAssign extends AbstractExpressionMixin {
   Expression buildExpression([Scope scope]) {
     return new AssignmentExpression(
       stringIdentifier(_name),
-      $equals,
+      _nullAware ? $nullAwareEquals : $equals,
       _value.buildExpression(scope),
     );
   }

lib/src/builders/expression/negate.dart

@@ -16,3 +16,20 @@ class _NegateExpression extends AbstractExpressionMixin {
     );
   }
 }
+
+class _NegativeExpression extends AbstractExpressionMixin {
+  final ExpressionBuilder _expression;
+
+  _NegativeExpression(this._expression);
+
+  @override
+  AstNode buildAst([Scope scope]) => buildExpression(scope);
+
+  @override
+  Expression buildExpression([Scope scope]) {
+    return new PrefixExpression(
+      $minus,
+      _expression.parentheses().buildExpression(scope),
+    );
+  }
+}

lib/src/builders/field.dart

@@ -22,7 +22,7 @@ FieldBuilder varField(
   );
 }
 
-/// Short-hand for [FieldBuilder].
+/// Short-hand for [FieldBuilder.asFinal].
 FieldBuilder varFinal(
   String name, {
   TypeBuilder type,
@@ -35,7 +35,7 @@ FieldBuilder varFinal(
   );
 }
 
-/// Short-hand for [FieldBuilder].
+/// Short-hand for [FieldBuilder.asConst].
 FieldBuilder varConst(
   String name, {
   TypeBuilder type,

lib/src/builders/file.dart

@@ -6,7 +6,7 @@ import 'package:analyzer/analyzer.dart';
 import 'package:code_builder/src/builders/shared.dart';
 import 'package:code_builder/src/tokens.dart';
 
-/// Lazily builds a file of Dart source code.
+/// Builds a file of Dart source code.
 ///
 /// See [LibraryBuilder] and [PartBuilder] for concrete implementations.
 abstract class FileBuilder implements AstBuilder<CompilationUnit> {
@@ -26,7 +26,7 @@ abstract class FileBuilder implements AstBuilder<CompilationUnit> {
   }
 }
 
-/// Lazily builds a standalone file (library) of Dart source code.
+/// Builds a standalone file (library) of Dart source code.
 class LibraryBuilder extends FileBuilder {
   final List<AstBuilder<Directive>> _directives = <AstBuilder<Directive>>[];
   final Scope _scope;

lib/src/builders/method.dart

@@ -209,12 +209,12 @@ abstract class MethodBuilder
   /// Creates a new [MethodBuilder] that returns `void`.
   factory MethodBuilder.returnVoid(String name, {ExpressionBuilder returns}) {
     if (returns == null) {
-      return new _MethodBuilderImpl(name, returns: core.$void);
+      return new _MethodBuilderImpl(name, returns: lib$core.$void);
     }
     return new _LambdaMethodBuilder(
       name,
       returns,
-      core.$void,
+      lib$core.$void,
       null,
     );
   }

lib/src/builders/parameter.dart

@@ -10,7 +10,7 @@ import 'package:code_builder/src/builders/shared.dart';
 import 'package:code_builder/src/builders/type.dart';
 import 'package:code_builder/src/tokens.dart';
 
-/// A more short-hand way of constructing a [ParameterBuilder].
+/// A short-hand way of constructing a [ParameterBuilder].
 ParameterBuilder parameter(
   String name, [
   Iterable<ValidParameterMember> members = const [],

lib/src/builders/type.dart

@@ -29,7 +29,7 @@ abstract class AbstractTypeBuilderMixin {
   }
 
   /// Invokes `const` on this type with a [name]d constructor.
-  NewInstanceBuilder constInstanceWith(
+  NewInstanceBuilder namedConstInstance(
     String name,
     Iterable<ExpressionBuilder> positional, [
     Map<String, ExpressionBuilder> named = const {},
@@ -50,7 +50,7 @@ abstract class AbstractTypeBuilderMixin {
   }
 
   /// Invokes `new` on this type with a [name]d constructor.
-  NewInstanceBuilder newInstanceWith(
+  NewInstanceBuilder namedNewInstance(
     String name,
     Iterable<ExpressionBuilder> positional, [
     Map<String, ExpressionBuilder> named = const {},

lib/src/builders/type/new_instance.dart

@@ -4,9 +4,9 @@ part of code_builder.src.builders.type;
 ///
 /// See [TypeBuilder]:
 /// - [TypeBuilder.constInstance]
-/// - [TypeBuilder.constInstanceWith]
+/// - [TypeBuilder.namedConstInstance]
 /// - [TypeBuilder.newInstance]
-/// - [TypeBuilder.newInstanceWith]
+/// - [TypeBuilder.namedNewInstance]
 abstract class NewInstanceBuilder
     implements AnnotationBuilder, InvocationBuilder {
   factory NewInstanceBuilder._const(TypeBuilder type, [String name]) {

lib/src/pretty_printer.dart

@@ -4,11 +4,21 @@
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/token.dart';
-import 'package:code_builder/code_builder.dart';
 import 'package:dart_style/dart_style.dart';
 
 import 'analyzer_patch.dart';
 
+final _dartFmt = new DartFormatter();
+
+/// Returns [source] formatted by `dartfmt`.
+String dartfmt(String source) {
+  try {
+    return _dartFmt.format(source);
+  } on FormatterException catch (_) {
+    return _dartFmt.formatStatement(source);
+  }
+}
+
 /// Augments [AstNode.toSource] by adding some whitespace/line breaks.
 ///
 /// The final result is run through `dartfmt`.

lib/src/scope.dart

@@ -30,10 +30,10 @@ Identifier identifier(Scope scope, String name, [String importFrom]) {
 ///       print(scope.identifier('Foo', 'package:foo/foo.dart'));
 ///
 ///       // May print 'i1.Bar'.
-///       print(scope.identifier('Bar'), 'package:foo/foo.dart');
+///       print(scope.identifier('Bar', 'package:foo/foo.dart'));
 ///
 ///       // May print 'i2.Bar'.
-///       print(scope.getIdentifier('Baz'), 'package:bar/bar.dart');
+///       print(scope.getIdentifier('Baz', 'package:bar/bar.dart'));
 ///     }
 abstract class Scope {
   /// A no-op [Scope]. Ideal for use for tests or example cases.
@@ -45,8 +45,8 @@ abstract class Scope {
 
   /// Create a new scoping context.
   ///
-  /// Actual implementation of is _not_ guaranteed, only that all import
-  /// prefixes will be unique in a given scope.
+  /// Actual implementation of [Scope] is _not_ guaranteed, only that all
+  /// import prefixes will be unique in a given scope.
   factory Scope() = _IncrementingScope;
 
   /// Create a context that just collects and de-duplicates imports.

lib/testing.dart

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:code_builder/code_builder.dart';
+import 'package:code_builder/src/pretty_printer.dart';
 import 'package:dart_style/dart_style.dart';
 import 'package:matcher/matcher.dart';