alsatian-test/alsatian

import { SpyCall } from "../spying";
import { ISpyCall } from "../_interfaces";

export class FunctionSpy {

    public readonly calls: Array<ISpyCall> = [];
    protected returnValue: any;
    protected hasReturnValue!: boolean;
    protected isStubbed!: boolean;
    protected context: any;
    private fakeFunction!: (...args: Array<any>) => any;

    public callsWithArguments(...args: Array<any>): Array<ISpyCall> {
        return this.calls.filter(call =>
            call.allArgumentsMatch.apply(call, args)
        );
    }

    public call(...args: Array<any>) {
        this.calls.push(new SpyCall(args));

        let returnValue: any;

        if (this.fakeFunction) {
            returnValue = this.fakeFunction.apply(this.context, args);
        }

        if (this.hasReturnValue) {
            return this.returnValue;
        }

        return returnValue;
    }

    public andReturn(returnValue: any) {
        this.returnValue = returnValue;
        this.hasReturnValue = true;
    }

    public andCall(fakeFunction: () => any) {
        this.isStubbed = true;
        this.fakeFunction = fakeFunction;
    }
}