feat(ferry_generator): add option to reuse data classes for fragments…

… with a single inline fragment spread as selection (#530)

* feat(ferry_generator): add data_class_config: reuse_fragment option in order to re-use selection sets with only a single inline fragment spread. see gql-dart/gql#413 for details.

In order to opt in to this (breaking) change, add

```yaml
          data_class_config:
            reuse_fragments: true
```
To your in the config for your graphql_builder of your build.yaml

examples/pokemon_explorer/pubspec.yaml

@@ -23,6 +23,6 @@ dev_dependencies:
   ferry_generator: ^0.8.2-dev.0
   flutter_test:
     sdk: flutter
-  gql_exec: ^0.4.4
+  gql_exec: ^1.0.0
 flutter:
   uses-material-design: true

packages/ferry_cache/test/test/data_change_streams_test.dart

@@ -26,10 +26,7 @@ final han = GHeroWithFragmentsData_hero(
     ..friendsConnection
         .edges
         .add(GHeroWithFragmentsData_hero_friendsConnection_edges(
-          (b) => b
-            ..node = GHeroWithFragmentsData_hero_friendsConnection_edges_node
-                    .fromJson(luke.toJson())!
-                .toBuilder(),
+          (b) => b..node = GheroDataData.fromJson(luke.toJson())!.toBuilder(),
         )),
 );
 
@@ -480,9 +477,7 @@ void main() {
                     .add(GHeroWithFragmentsData_hero_friendsConnection_edges(
                   (b) => b
                     ..node =
-                        GHeroWithFragmentsData_hero_friendsConnection_edges_node
-                                .fromJson(vader.toJson())!
-                            .toBuilder(),
+                        GheroDataData.fromJson(vader.toJson())!.toBuilder(),
                 ))));
 
         await Future.delayed(Duration.zero);

packages/ferry_generator/lib/graphql_builder.dart

@@ -87,6 +87,7 @@ class GraphqlBuilder implements Builder {
         p.basename(generatedFilePath(buildStep.inputId, dataExtension)),
         config.typeOverrides,
         config.whenExtensionConfig,
+        config.dataClassConfig,
       ),
       varExtension: buildVarLibrary(
         doc,

packages/ferry_generator/lib/src/utils/config.dart

@@ -21,6 +21,7 @@ class BuilderConfig {
   final String outputDir;
   final String sourceExtension;
   final InlineFragmentSpreadWhenExtensionConfig whenExtensionConfig;
+  final DataClassConfig dataClassConfig;
 
   BuilderConfig(Map<String, dynamic> config)
       : schemaId = config['schema'] == null
@@ -37,7 +38,22 @@ class BuilderConfig {
         enumFallbackConfig = _getEnumFallbackConfig(config),
         outputDir = config['output_dir'] ?? '__generated__',
         sourceExtension = config['source_extension'] ?? '.graphql',
-        whenExtensionConfig = _getWhenExtensionConfig(config);
+        whenExtensionConfig = _getWhenExtensionConfig(config),
+        dataClassConfig = _getDataClassConfig(config);
+}
+
+DataClassConfig _getDataClassConfig(Map<String, dynamic> config) {
+  final dataClassConfig = switch (config) {
+    {
+      'data_class_config': {
+        'reuse_fragments': final reuseFragments,
+      }
+    } =>
+      DataClassConfig(reuseFragments: reuseFragments == true),
+    _ => const DataClassConfig(reuseFragments: false),
+  };
+
+  return dataClassConfig;
 }
 
 InlineFragmentSpreadWhenExtensionConfig _getWhenExtensionConfig(

packages/ferry_generator/pubspec.yaml

@@ -4,17 +4,17 @@ homepage: https://ferrygraphql.com/
 description: Generated types for Ferry GraphQL Client
 repository: https://github.com/gql-dart/ferry
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: '>=3.0.0 <4.0.0'
 dependencies:
   gql: '>=0.14.0 <2.0.0'
-  gql_code_builder: ^0.7.1
+  gql_code_builder: ^0.8.0
   built_collection: ^5.0.0
   code_builder: ^4.3.0
   build: ^2.0.0
   path: ^1.8.0
   ferry_exec: ^0.3.1
   yaml: ^3.1.0
-  dart_style: ^2.2.4
+  dart_style: ^2.3.2
   glob: ^2.0.1
   built_value_generator: ^8.1.1
   built_value: ^8.1.2

packages/ferry_test_graphql2/build.yaml

@@ -5,6 +5,8 @@ targets:
         enabled: true
         options:
           schema: ferry_test_graphql2|lib/schema/schema.graphql
+          data_class_config:
+            reuse_fragments: true
           type_overrides:
             Date:
               name: DateTime