Compile-Time Dependency Injection for Dart & Flutter

This package provides the annotations used to declare a compile-time dependency injection (DI) graph. It is a modern, sound null-safe port of the original inject.dart from Google.

Since this library generates code at compile time, it does not rely on runtime reflection (such as dart:mirrors). This ensures maximum performance and minimal build sizes for Flutter and standalone Dart applications.

Getting Started

Add inject_compile as a dependency and inject_compile_generator as a dev dependency in your pubspec.yaml file:

dependencies:
  inject_compile: ^0.9.0

dev_dependencies:
  build_runner: ^2.4.0
  inject_compile_generator: ^0.9.0

Annotations

@provide

Marks a constructor, method, or getter as providing a dependency.

• On a class constructor: Registers the class in the dependency graph so the framework knows how to instantiate it.
• On a module method/getter: Registers the return type as a dependency. The framework calls this member to obtain the instance.

@module

Marks a class as a module. Modules contain provider methods for dependencies that cannot be easily instantiated directly (such as interfaces, third-party classes, or asynchronous resources).

@injector

Marks an abstract class as the root of a dependency injection graph. The code generator creates a concrete implementation subclass (e.g., YourClass$Injector) implementing this interface.

@singleton

Combined with @provide, indicates that a dependency is instantiated only once per injector instance. All subsequent requests return the same instance.

@asynchronous

Marks a provider method returning a Future as asynchronous. The generated injector awaits the future during creation, resolving the value synchronously for any dependent classes.

@Qualifier

Differentiates multiple bindings of the same type by associating a symbol (e.g., @Qualifier(#name)) with the provider.

Next Steps

• To run the generator, refer to the inject_compile_generator package page.
• For complete samples, see the workspace examples.