TypeSentinel 🫡

Check for existing type aliases given a custom type.

Why?

I was working on a project and while i was going through the code i was seeing a lot of duplicated types declaration so i took this opportunity to learn more about Typescript APIs

What does it do?

Say you have

// file1.ts
type NullableString = string | null

// file2.ts
type AnotherNullableString = string | null

TypeSentinel will tell you that you already have one or multiple type alias(es) with that exact same values, returning:

• the name of the type alias that you already have
• the usage count (how many times was that type alias used in your project)

TypeSentinel currently supports

• Types aliases with the same name

• Searching types with generics

• Interfaces declarations

By default it skips the node_modules folder, but you can customize it with a config.json

{
  "skip": ["node_modules", "sentinel.ts", "index.ts"],
  "collectTypes": true
}

in the same path of your process.cwd().

Run it

Fast way

npm link && typesentinel

Development

pnpm tsc

1. Make it executable

pnpm makex

2. Add Shebang to ./build/index.js

#!/usr/bin/env node

// rest of the file

3. Link

npm link

4. Run it

typesentinel