One of These Things Is Not Like The Others

There's a programming principle we saw earlier in the book called the Single Responsibility Principle.

When looking at classes or methods that are doing too much, using the SRP as a guiding light can help us to make code that is easier to maintain, less coupled, and therefore leads to fewer bugs.

Let's look at a generic User class that might be similar to code that you've seen before:

class User {
    public firstName: string;
    public lastName: string;
    public id: number;
    public jwtToken: string;
    public homeAddress: string;
    public creditCardNo: string;
    public getFullName(): string {
        return this.firstName + " " + this.lastName;
    }
    public decodeJwtToken(): string {
        return decode(this.jwtToken);
    }
}

Look familiar?

Given the name of the class, we should start to be suspicious that it's too generic a class...

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