April 18th, 2020
Create cli tool using Typescript
#js
#nodejs
#typescript
#cli
img

Just created my first cli tool in Typescript. Sharing here the experience and steps

Target tool

I want to create a command line tool that will do something like this

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ctc '[{ "index":3, "text":"I would like some gelb bananen bitte", "value":200 }, { "index":4, "text":"I hope batch update is working", "value":300   } ]'

//output

┌───────┬──────────────────────────────────────┬───────┐
│ index │                                 text │ value │
├───────┼──────────────────────────────────────┼───────┤
│     3 │ I would like some gelb bananen bitte │   200 │
│     4 │       I hope batch update is working │   300 │
└───────┴──────────────────────────────────────┴───────┘

Lets follow these steps to make it happen

Make index.ts command line runnable

Add this line at the beginning of your code to make your program running by bash command

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#!/usr/bin/env node

change in package.json

First add bin field. This declares which commands you can run

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{
  "bin": {
    "ctc": "dist/index.js"
  }
}

Adding nodes types

This is required because you might use process.argv to read the command line arguments

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npm install --save-dev @types/node

Also add this in tsconfig files

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{
  "compilerOptions": {
    "types": ["node"]
  }
}

Testing

First install transpile and install it globally

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npx tsc ; npm link

Now run the program

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ctc '[{ "index":3, "text":"I would like some gelb bananen bitte", "value":200 }, { "index":4, "text":"I hope batch update is working", "value":300   } ]'


//output
┌───────┬──────────────────────────────────────┬───────┐
│ index │                                 text │ value │
├───────┼──────────────────────────────────────┼───────┤
│     3 │ I would like some gelb bananen bitte │   200 │
│     4 │       I hope batch update is working │   300 │
└───────┴──────────────────────────────────────┴───────┘

Source

  1. Same but in nodejs. https://blog.bitsrc.io/how-to-build-a-command-line-cli-tool-in-nodejs-b8072b291f81
  2. in ts: https://itnext.io/how-to-create-your-own-typescript-cli-with-node-js-1faf7095ef89
  3. https://stackoverflow.com/questions/53529521/typescript-error-cannot-find-name-process
  4. Nice article on how to write test of you cli: https://medium.com/@zorrodg/integration-tests-on-node-js-cli-part-1-why-and-how-fa5b1ba552fe