feat(generator): support output_dir and build_extensions config for generated files

Now the code generator supports specifying a custom output directory and extension/name template for generated DI files via build.yaml ( and ). This allows placing all generated code in custom folders and using flexible naming schemes.

docs: update all user docs and tutorials to explain new output_dir/build_extensions config

- Added detailed usage and YAML examples to cherrypick_generator/README.md
- Synced full_tutorial_en.md and full_tutorial_ru.md (advanced codegen section) with explanation of new configuration and impact on imports
- Updated quick_start_en.md and quick_start_ru.md to mention advanced customization and point to tutorials
- Added troubleshooting and tips for custom output/imports in docs

cherrypick_generator/README.md

@@ -4,6 +4,50 @@
 
 ---
 
+### Advanced: Customizing Generated File Paths (`build_extensions`)
+
+You can further control the filenames and subdirectory structure of generated files using the `build_extensions` option in `build.yaml`. This is especially useful in large apps for keeping DI artifacts organized under `lib/generated/` or any custom location.
+
+**Example advanced build.yaml:**
+
+```yaml
+targets:
+  $default:
+    builders:
+      cherrypick_generator|inject_generator:
+        options:
+          build_extensions:
+            '^lib/app.dart': ['lib/generated/app.inject.cherrypick.g.dart']
+          output_dir: lib/generated
+        generate_for:
+          - lib/**.dart
+      cherrypick_generator|module_generator:
+        options:
+          build_extensions:
+            '^lib/di/{{}}.dart': ['lib/generated/di/{{}}.module.cherrypick.g.dart']
+          output_dir: lib/generated
+        generate_for:
+          - lib/**.dart
+```
+
+- **output_dir**: Path where all generated files are placed (e.g., `lib/generated`)
+- **build_extensions**: Allows templating of generated filenames and locations. You can use wildcards like `{{}}` to keep directory structure or group related files.
+
+**If you use these options, be sure to update your imports accordingly, for example:**
+
+```dart
+import 'package:your_package/generated/app.inject.cherrypick.g.dart';
+import 'package:your_package/generated/di/app_module.module.cherrypick.g.dart';
+```
+
+### FAQ / Troubleshooting
+
+- If files are missing or located in unexpected directories, double-check your `output_dir` and `build_extensions` configuration.
+- If you change generation paths, always update your imports in the codebase.
+- These options are backward compatible: omitting them preserves pre-existing (side-by-source) output behavior.
+
+---
+
 ## Features
 
 - **Automatic Field Injection:**  
@@ -170,6 +214,26 @@ final class $MyModule extends MyModule {
 
 ## Advanced Usage
 
+### Custom output directory for generated code (output_dir)
+
+You can control the directory where the generated files (`*.inject.cherrypick.g.dart`, `*.module.cherrypick.g.dart`) are placed using the `output_dir` option in your `build.yaml`:
+
+```yaml
+targets:
+  $default:
+    builders:
+      cherrypick_generator|injectBuilder:
+        options:
+          output_dir: lib/generated
+      cherrypick_generator|moduleBuilder:
+        options:
+          output_dir: lib/generated
+```
+
+**If `output_dir` is omitted, generated files are placed next to the original sources (default behavior).**
+
+After running code generation, you will find files like `lib/generated/app.inject.cherrypick.g.dart` and `lib/generated/your_module.module.cherrypick.g.dart`. You can import them as needed from that directory.
+
 - **Combining Modules and Field Injection:**  
   It's possible to mix both style of DI — modules for binding, and field injection for consuming services.
 - **Parameter and Named Injection:**  

cherrypick_generator/build.yaml

@@ -1,20 +1,18 @@
 builders:
-  module_generator:
-    import: "package:cherrypick_generator/module_generator.dart"
-    builder_factories: ["moduleBuilder"]
-    build_extensions: {".dart": [".module.cherrypick.g.dart"]}
-    auto_apply: dependents
-    required_inputs: ["lib/**"]
-    runs_before: []
-    build_to: source
   inject_generator:
     import: "package:cherrypick_generator/inject_generator.dart"
     builder_factories: ["injectBuilder"]
     build_extensions: {".dart": [".inject.cherrypick.g.dart"]}
     auto_apply: dependents
-    required_inputs: ["lib/**"]
-    runs_before: []
     build_to: source
+    applies_builders: ["source_gen|combining_builder"]
+  module_generator:
+    import: "package:cherrypick_generator/module_generator.dart"
+    builder_factories: ["moduleBuilder"]
+    build_extensions: {".dart": [".module.cherrypick.g.dart"]}
+    auto_apply: dependents
+    build_to: source
+    applies_builders: ["source_gen|combining_builder"]
 
 targets:
   $default:
@@ -24,4 +22,4 @@ targets:
           - lib/**.dart
       cherrypick_generator|inject_generator:
         generate_for:
-          - lib/**.dart
+          - lib/**.dart

cherrypick_generator/lib/cherrypick_custom_builders.dart

@@ -0,0 +1,76 @@
+import 'dart:async';
+import 'package:build/build.dart';
+import 'package:path/path.dart' as p;
+import 'package:source_gen/source_gen.dart';
+import 'inject_generator.dart';
+import 'module_generator.dart';
+
+/// Универсальный Builder для генераторов Cherrypick с поддержкой кастомного output_dir
+/// (указывает директорию для складывания сгенерированных файлов через build.yaml)
+class CustomOutputBuilder extends Builder {
+  final Generator generator;
+  final String extension;
+  final String outputDir;
+  final Map<String, List<String>> customBuildExtensions;
+
+  CustomOutputBuilder(this.generator, this.extension, this.outputDir, this.customBuildExtensions);
+
+  @override
+  Map<String, List<String>> get buildExtensions {
+    if (customBuildExtensions.isNotEmpty) {
+      return customBuildExtensions;
+    }
+    // Дефолт: рядом с исходником, как PartBuilder
+    return {
+      '.dart': [extension],
+    };
+  }
+
+  @override
+  Future<void> build(BuildStep buildStep) async {
+    final inputId = buildStep.inputId;
+    print('[CustomOutputBuilder] build() called for input: \\${inputId.path}');
+    final library = await buildStep.resolver.libraryFor(inputId);
+    print('[CustomOutputBuilder] resolved library for: \\${inputId.path}');
+    final generated = await generator.generate(LibraryReader(library), buildStep);
+    print('[CustomOutputBuilder] gen result for input: \\${inputId.path}, isNull: \\${generated == null}, isEmpty: \\${generated?.isEmpty}');
+    if (generated == null || generated.isEmpty) return;
+    String outputPath;
+    if (customBuildExtensions.isNotEmpty) {
+      // Кастомная директория/шаблон
+      final inputPath = inputId.path;
+      final relativeInput = p.relative(inputPath, from: 'lib/');
+      final parts = p.split(relativeInput);
+      String subdir = '';
+      String baseName = parts.last.replaceAll('.dart', '');
+      if (parts.length > 1) {
+        subdir = parts.first; // Например, 'di'
+      }
+      outputPath = subdir.isEmpty
+        ? p.join('lib', 'generated', '$baseName$extension')
+        : p.join('lib', 'generated', subdir, '$baseName$extension');
+    } else {
+      // Дефолт: рядом с исходником
+      outputPath = p.setExtension(inputId.path, extension);
+    }
+    final outputId = AssetId(inputId.package, outputPath);
+    // part of - всегда авто!
+    final partOfPath = p.relative(inputId.path, from: p.dirname(outputPath));
+    final codeWithPartOf = "part of '$partOfPath';\n\n$generated";
+    print('[CustomOutputBuilder] writing to output: \\${outputId.path}');
+    await buildStep.writeAsString(outputId, codeWithPartOf);
+    print('[CustomOutputBuilder] successfully written for input: \\${inputId.path}');
+  }
+}
+
+Builder injectCustomBuilder(BuilderOptions options) {
+  final outputDir = options.config['output_dir'] as String? ?? '';
+  final buildExtensions = (options.config['build_extensions'] as Map?)?.map((k,v)=>MapEntry(k.toString(), (v as List).map((item)=>item.toString()).toList())) ?? {};
+  return CustomOutputBuilder(InjectGenerator(), '.inject.cherrypick.g.dart', outputDir, buildExtensions);
+}
+
+Builder moduleCustomBuilder(BuilderOptions options) {
+  final outputDir = options.config['output_dir'] as String? ?? '';
+  final buildExtensions = (options.config['build_extensions'] as Map?)?.map((k,v)=>MapEntry(k.toString(), (v as List).map((item)=>item.toString()).toList())) ?? {};
+  return CustomOutputBuilder(ModuleGenerator(), '.module.cherrypick.g.dart', outputDir, buildExtensions);
+}

cherrypick_generator/lib/inject_generator.dart

@@ -19,6 +19,7 @@ import 'package:build/build.dart';
 import 'package:source_gen/source_gen.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:cherrypick_annotations/cherrypick_annotations.dart' as ann;
+import 'cherrypick_custom_builders.dart' as custom;
 
 /// InjectGenerator generates a mixin for a class marked with @injectable()
 /// and injects all fields annotated with @inject(), using CherryPick DI.
@@ -204,4 +205,4 @@ class _ParsedInjectField {
 ///
 /// Фабрика билдера. Используется build_runner.
 Builder injectBuilder(BuilderOptions options) =>
-    PartBuilder([InjectGenerator()], '.inject.cherrypick.g.dart');
+    custom.injectCustomBuilder(options);

cherrypick_generator/lib/module_generator.dart

@@ -15,9 +15,8 @@ import 'package:analyzer/dart/element/element.dart';
 import 'package:build/build.dart';
 import 'package:source_gen/source_gen.dart';
 import 'package:cherrypick_annotations/cherrypick_annotations.dart' as ann;
-
 import 'src/generated_class.dart';
-
+import 'cherrypick_custom_builders.dart' as custom;
 /// ---------------------------------------------------------------------------
 /// ModuleGenerator for code generation of dependency-injected modules.
 ///
@@ -89,5 +88,8 @@ class ModuleGenerator extends GeneratorForAnnotation<ann.module> {
 /// Возвращает Builder, используемый build_runner для генерации кода для всех
 /// файлов, где встречается @module().
 /// ---------------------------------------------------------------------------
+
+
+
 Builder moduleBuilder(BuilderOptions options) =>
-    PartBuilder([ModuleGenerator()], '.module.cherrypick.g.dart');
+    custom.moduleCustomBuilder(options);

cherrypick_generator/pubspec.yaml

@@ -18,6 +18,7 @@ dependencies:
   build: ^2.4.1
   source_gen: ^2.0.0
   collection: ^1.18.0
+  path: ^1.9.1
 
 dev_dependencies:
   lints: ^4.0.0