Add examples of how existing generators might use augmentations.

pkgs/_augmentation_examples/analysis_options.yaml

@@ -0,0 +1,6 @@
+include: package:dart_flutter_team_lints/analysis_options.yaml
+
+analyzer:
+  enable-experiment:
+    - enhanced-parts
+    - macros

pkgs/_augmentation_examples/lib/built_value.dart

@@ -0,0 +1,141 @@
+// Copyright (c) 2024, Google Inc. Please see the AUTHORS file 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:built_collection/built_collection.dart';
+import 'package:built_value/built_value.dart';
+import 'package:built_value/json_object.dart';
+import 'package:built_value/serializer.dart';
+
+part 'built_value.g.dart';
+
+abstract class SimpleValue implements Built<SimpleValue, SimpleValueBuilder> {
+  static Serializer<SimpleValue> get serializer => _$simpleValueSerializer;
+
+  int get anInt;
+
+  String? get aString;
+
+  factory SimpleValue([void Function(SimpleValueBuilder) updates]) =
+      _$SimpleValue;
+  SimpleValue._();
+}
+
+abstract class VerySimpleValue
+    implements Built<VerySimpleValue, VerySimpleValueBuilder> {
+  static Serializer<VerySimpleValue> get serializer =>
+      _$verySimpleValueSerializer;
+
+  int get value;
+
+  factory VerySimpleValue(int value) => _$VerySimpleValue._(value: value);
+  VerySimpleValue._();
+}
+
+abstract class CompoundValue
+    implements Built<CompoundValue, CompoundValueBuilder> {
+  static Serializer<CompoundValue> get serializer => _$compoundValueSerializer;
+
+  SimpleValue get simpleValue;
+  ValidatedValue? get validatedValue;
+
+  factory CompoundValue([void Function(CompoundValueBuilder) updates]) =
+      _$CompoundValue;
+  CompoundValue._();
+}
+
+abstract class ValidatedValue
+    implements Built<ValidatedValue, ValidatedValueBuilder> {
+  static Serializer<ValidatedValue> get serializer =>
+      _$validatedValueSerializer;
+
+  int get anInt;
+  String? get aString;
+
+  factory ValidatedValue([void Function(ValidatedValueBuilder) updates]) =
+      _$ValidatedValue;
+
+  ValidatedValue._() {
+    if (anInt == 7) throw StateError('anInt may not be 7');
+  }
+}
+
+abstract class ValueWithCode
+    implements Built<ValueWithCode, ValueWithCodeBuilder> {
+  static final int youCanHaveStaticFields = 3;
+
+  int get anInt;
+  String? get aString;
+
+  String get youCanWriteDerivedGetters => anInt.toString() + aString!;
+
+  factory ValueWithCode([void Function(ValueWithCodeBuilder) updates]) =
+      _$ValueWithCode;
+  ValueWithCode._();
+
+  factory ValueWithCode.fromCustomFactory(int anInt) => ValueWithCode(
+    (b) =>
+        b
+          ..anInt = anInt
+          ..aString = 'two',
+  );
+}
+
+abstract class ValueWithDefaults
+    implements Built<ValueWithDefaults, ValueWithDefaultsBuilder> {
+  int get anInt;
+  String? get aString;
+
+  factory ValueWithDefaults([void Function(ValueWithDefaultsBuilder) updates]) =
+      _$ValueWithDefaults;
+  ValueWithDefaults._();
+}
+
+abstract class ValueWithDefaultsBuilder
+    implements Builder<ValueWithDefaults, ValueWithDefaultsBuilder> {
+  int anInt = 7;
+
+  String? aString;
+
+  factory ValueWithDefaultsBuilder() = _$ValueWithDefaultsBuilder;
+  ValueWithDefaultsBuilder._();
+}
+
+abstract class DerivedValue
+    implements Built<DerivedValue, DerivedValueBuilder> {
+  int get anInt;
+
+  @memoized
+  int get derivedValue => anInt + 10;
+
+  @memoized
+  Iterable<String> get derivedString => [toString()];
+
+  factory DerivedValue([void Function(DerivedValueBuilder) updates]) =
+      _$DerivedValue;
+  DerivedValue._();
+}
+
+abstract class Account implements Built<Account, AccountBuilder> {
+  static Serializer<Account> get serializer => _$accountSerializer;
+  int get id;
+  String get name;
+  BuiltMap<String, JsonObject> get keyValues;
+
+  factory Account([void Function(AccountBuilder) updates]) = _$Account;
+  Account._();
+}
+
+@BuiltValue(wireName: 'V')
+abstract class WireNameValue
+    implements Built<WireNameValue, WireNameValueBuilder> {
+  static Serializer<WireNameValue> get serializer => _$wireNameValueSerializer;
+
+  @BuiltValueField(wireName: 'v')
+  int get value;
+
+  factory WireNameValue([void Function(WireNameValueBuilder) updates]) =
+      _$WireNameValue;
+
+  WireNameValue._();
+}