Autowiring seems only to work with private constructor properties

[abadb]

Let's assume the following case:

1. Using the container loading a YAML file
2. Autowiring is set to true.

Then, If I have:

1. An interface

export default interface QueryBus {
    ask<R extends Response>(query: Query): Promise<R>;
}

3. An implementation of this interface

export default class SimpleQueryBus implements QueryBus {
    constructor(private readonly handlers: QueryHandlersRegistry) {

    }
}

4. A client which uses this QueryBus interface:

   export default class SampleGetController implements ControllerBase {
   
   private queryBus: QueryBus;
   
   constructor(queryBus: QueryBus) {
       this.queryBus = queryBus;
   }
   }

If using autowiring (loading a YAML file):

services:

  _defaults:
    autowire: true

The const typeNameForArgument assignment will fail on the async _getDefinition(classDeclaration, body, parsedFile, ServiceClass) method:

for (const parameterDeclaration of constructorParams) {
        const typeNameForArgument = parameterDeclaration.parameter.typeAnnotation.typeAnnotation.typeName.name;
        const argumentId = await this._getIdentifierFromImports(typeNameForArgument, body, parsedFile);
        if (!argumentId) {
          continue;
        }
        definition.addArgument(new _Reference.default(argumentId), definition.abstract);
      }

When resolving the StatusGetController service, it will throw an exception.

I think this happens because the typescript-eslint parser returns a different data structure when resolving constructors which dont use private properties.

If using private constructor properties:

interface TestInterface {

}

class ExampleClass {

  constructor(private readonly parameter: TestInterface) {

  }

}

The parameterDeclaration.parameter.typeAnnotation.typeAnnotation.typeName.name will be present, as resolved by the typescript-eslint parser:

However, if not using private property constructors, like:

interface TestInterface {

}

class ExampleClass {

  private thing: TestInterface;

  constructor(parameter: TestInterface) {
    this.thing = parameter;
  }

}

The parameterDeclaration.parameter.typeAnnotation.typeAnnotation.typeName.name will throw an error, because typescript-eslint resolves this structure to:

And the parameter.typeAnnotation property does not exist when using this declaration.

So, I would suggest to change the documentation to reflect that autowiring only works with private constructor properties.

[zazoomauro]

@abadb Thanks! I'll update the documentation in order to reflect your suggestion. As well I will create a task in order to make it working with protected and public attributes on constructor

[zazoomauro]

https://github.com/zazoomauro/node-dependency-injection/wiki/Autowire