Require that interface names be prefixed with I (interface-name-prefix)

It can be hard to differentiate between classes and interfaces. Prefixing interfaces with “I” can help telling them apart at a glance.

Rule Details

This rule enforces consistency of interface naming prefix conventions.

Options

This rule has a string option.

• "never" (default) disallows all interfaces being prefixed with "I"
• "always" requires all interfaces be prefixed with "I"

never

TypeScript suggests never prefixing interfaces with “I”.

The following patterns are considered warnings:

interface IAnimal {
  name: string;
}

The following patterns are not warnings:

interface Animal {
  name: string;
}

always

The following patterns are considered warnings:

interface Animal {
  name: string;
}

The following patterns are not warnings:

interface IAnimal {
  name: string;
}

When Not To Use It

If you do not want to enforce interface name prefixing.

Further Reading

TypeScript Interfaces

Compatibility

TSLint: interface-name