Function createConstructor

component/constructor.go:36–55

createConstructor validates the given ConstructorFunc and builds a Constructor metadata struct. It ensures that the function is non-nil, is of kind Func, and returns exactly one result. If valid, it extracts the argument types and returns a populated Constructor.

(fn ConstructorFunc)

// It ensures that the function is non-nil, is of kind Func, and returns exactly one result.
// If valid, it extracts the argument types and returns a populated Constructor.
func createConstructor(fn ConstructorFunc) (Constructor, error) {
	if fn == nil {
		return Constructor{}, fmt.Errorf("nil constructor")
	}

	fnType := reflect.TypeOf(fn)
	if fnType.Kind() != reflect.Func {
		return Constructor{}, fmt.Errorf("constructor must be a function")
	}

	if fnType.NumOut() != 1 {
		return Constructor{}, fmt.Errorf("constructor must only return one result")
	}

	return Constructor{
		fnType:  fnType,
		fnValue: reflect.ValueOf(fn),
		args:    extractConstructorArgs(fnType),
	}, nil
}

// OutType returns the type of the constructor function's output.
func (f Constructor) OutType() reflect.Type {