Description:

In the property injection strategy, in @automock/adapters.nestjs, I was trying to instantiate a class using the new keyword, I encountered an issue where the reflection hooks were attempting to access a property of one of the class dependencies, resulting in a failure. The property did not exist because the class was instantiated with empty parameters.

Example

Here is a code snippet that demonstrates the issue:

Suppose that the decorator @Decorator() tries to use a property from "dep: Dependency"

class Dependency {
  constructor() {}
}

class TargetClass {
  constructor(@Decorator() dep: Dependency) {}
}

// This results in an error
const instance = new TargetClass();

The reflection hooks are attempting to use dep.someProperty, but it's not defined because TargetClass was instantiated without parameters.

Solution

I found that using Object.create instead of the new keyword fixed this issue. Here's an example of how I made the change:

// Create an object with the prototype of TargetClass
const instance = Object.create(TargetClass.prototype);

By using Object.create, the class dependencies were properly initialized, and the reflection hooks were able to access the required properties without errors.

Expected Behavior

The expected behavior is that the class instantiation should handle the dependencies correctly, without resulting in errors when properties are accessed by the reflection hooks.