Inject
Parameter decorator on a dependency parameter of a class constructor that specifies a custom provider of the dependency.
| Option | Description |
|---|---|
token
|
A DI token that maps to the dependency to be injected. |
See also
Usage notes
The following example shows a class constructor that specifies a custom provider of a dependency using the parameter decorator.
When @Inject() is not present, the injector uses the type annotation of the
parameter as the provider.
class Engine {}
@Injectable()
class Car {
constructor(public engine: Engine) {} // same as constructor(@Inject(Engine) engine:Engine)
}
const injector = Injector.create({
providers: [
{provide: Engine, deps: []},
{provide: Car, deps: [Engine]},
],
});
expect(injector.get(Car).engine instanceof Engine).toBe(true);