fix: revise README.md and add actual_data test

Author: b2nkuu

README.md

@@ -314,28 +314,6 @@ class $AssetsImagesGen {
 }
 ```
 
-#### Support generate at **build.yaml**
-Support generates dart files based on the key **`targets.$default.builders`** and **`flutter_gen.options`** 
-of [`build.yaml`](https://github.com/dart-lang/build/blob/master/build_config/README.md).
-
-```yaml
-# build.yaml
-# ...
-
-targets:
-  $default:
-    builders:
-      flutter_gen:
-        options: 
-          output: lib/build_gen/ # Optional (default: lib/gen/)
-          line_length: 120 # Optional (default: 80)
-```
-##### Prority of configure (High -> Low)
-```
-build.yaml -> pubspec.yaml -> default_config
-```
-
-
 #### Including additional metadata
 
 At build time, additional metadata may be included in the generated class, by using the

packages/core/test/assets_gen_test.dart

@@ -213,6 +213,15 @@ void main() {
       final names = got.map((e) => e.name);
       expect(names.sorted(), tests.values.sorted());
     });
+
+    test('Assets on pubspec_assets.yaml and override with build_assets.yaml ', () async {
+      const pubspec = 'test_resources/pubspec_assets.yaml';
+      const build = 'test_resources/build_assets.yaml';
+      const fact = 'test_resources/actual_data/build_assets.gen.dart';
+      const generated = 'test_resources/lib/build_gen/assets.gen.dart';
+
+      await expectedAssetsGen(pubspec, generated, fact, build: build);
+    });
   });
 
   group('Test generatePackageNameForConfig', () {

packages/core/test/flutter_gen_test.dart

@@ -180,12 +180,12 @@ void main() {
       expect(File('test_resources/lib/gen/$colors').existsSync(), false);
     });
 
-    test('with build_output.yaml', () async {
+    test('With build_output.yaml', () async {
       const pubspec = 'test_resources/pubspec_normal.yaml';
       const build = 'test_resources/build_output.yaml';
-      const assets = 'pubspec_assets.gen.dart';
-      const colors = 'pubspec_colors.gen.dart';
-      const fonts = 'pubspec_fonts.gen.dart';
+      const assets = 'build_assets.gen.dart';
+      const colors = 'build_colors.gen.dart';
+      const fonts = 'build_fonts.gen.dart';
 
       await FlutterGenerator(
         File(pubspec),

packages/core/test/gen_test_helper.dart

@@ -14,15 +14,21 @@ Future<void> clearTestResults() async {}
 Future<List<String>> runAssetsGen(
   String pubspec,
   String generated,
-  String fact,
-) async {
+  String fact, {
+  String? build,
+}) async {
+  final pubspecFile = File(pubspec);
+
+  File? buildFile;
+  if (build != null) buildFile = File(build);
+
   await FlutterGenerator(
-    File(pubspec),
+    pubspecFile,
+    buildFile: buildFile,
     assetsName: p.basename(generated),
   ).build();
 
-  final pubspecFile = File(pubspec);
-  final config = loadPubspecConfig(pubspecFile);
+  final config = loadPubspecConfig(pubspecFile, buildFile: buildFile);
   final formatter = DartFormatter(
     pageWidth: config.pubspec.flutterGen.lineLength,
     lineEnding: '\n',
@@ -42,9 +48,10 @@ Future<List<String>> runAssetsGen(
 Future<void> expectedAssetsGen(
   String pubspec,
   String generated,
-  String fact,
-) async {
-  final results = await runAssetsGen(pubspec, generated, fact);
+  String fact, {
+  String? build,
+}) async {
+  final results = await runAssetsGen(pubspec, generated, fact, build: build);
   final actual = results.first, expected = results.last;
   expect(
     File(generated).readAsStringSync(),