Extract and Override Call example

ExtractAndOverrideCall.ts

class Account {
    private balance: number;
    private readonly logger: AcmeLogger;

    constructor(balance: number) {
        this.balance = balance;
        this.logger = new AcmeLogger();
    }

    public withdraw(value: number): void {
        this.balance += value;
        this.logger.logTransaction(new Date(), -value); // <- the call to the awkward dependency
    }
}

//////////////////////////////////////////////

// After extracting the call to the awkward dependency to a new method

class Account {
    private balance: number;
    private readonly logger: AcmeLogger;

    constructor(balance: number) {
        this.balance = balance;
        this.logger = new AcmeLogger();
    }

    public withdraw(value: number): void {
        this.balance += value;
        this.logWithdraw(value);
    }

    private logWithdraw(value: number): void {
        this.logger.logTransaction(new Date(), -value);
    }
}

// Which is the starting point of Subclass & Override Method 
// See https://gist.github.com/trikitrok/2909137a57a2d0bb2c2a906bfe657e87