Built-in rules

tslint has a handy collection of built-in rulesets that can be used. We can use these by specifying the ruleset name in the extends field. We can use multiple rulesets by putting all their names in the array:

1. Let's adopt the opinionated set of rules that tslint ships with, called "tslint:recommended". So, in our tslint.json file, let's remove the rules field and add an extends field, as follows:

{
  "extends": ["tslint:recommended"]
}

We immediately get lint errors when tslint.json is saved. The error is complaining about the lack of an I prefix on our Product interface. The logic behind the rule is that, while reading code, if a type starts with an I, we immediately know that it is an interface.

1. Let's pretend that this rule isn't valuable to us. We can override this rule from "tslint:recommended" in the "rules" field. The rule is called "interface-name". So, let's override this to false:

{
  "extends": ["tslint:recommended"],
  "rules": {
    "interface-name": false
  }
}

When tslint.json is saved, the linting errors immediately go away.