ignore-bad-ts

This project provides various CLI and programmatic APIs to avoid type-checking failures in external libraries that you have no control over. This is meant to enable you to keep stricter type safety in your project without being unable to use typescript as your main compiler.

Installation

    ## Example Globally
    npm install -g ignore-bad-ts

    ## Example Per project
    yarn add --dev ignore-bad-ts

How this could happen:

Perhaps you've found yourself in this situation. You love typescript and all the security and scalability that it provides.

However, you're in an organization that is only now learning to love typescript like you. And they're learning at a code-fast, type-later pace.

They ask you to do this:

import CompanyModule from 'my-company-module';

// All your awesome typed code here

And when you run it, you're seeing errors from... your node_modules!

node_modules/my-company-module/src/it-has-ts-at-least.ts - error TS7053 Element implicitly has an 'any' type...

Admittedly, the above error isn't THAT critical of a rule, but you still can't compile without changing your tsconfig. So what happened?

Well...

• maybe your co-workers decided to turn off particular best-practice settings and/or only provide their code as untranspiled es6.
• maybe your co-workers liked the idea of typescript in IDE for intellisense but have been transpiling with babel instead
• maybe there is literally no declaration files or broken declaration files due to bad CI/CD

So what do you do?

You could just disable all typescript compilation and use something like babel to transpile without the typechecking.

Hark, my friend! Do no let your code quality and type-checking slide so that your own codebase can be broken later on too!

Instead you have ignore-bad-ts!

What does it do?

In short, the scripts in this package will add "@ts-nocheck" at the top of all .ts(x) files that match the globs you provide. This solution may become deprecated if per module type checking is added to the typescript compiler itself.

Usage

CLI

Once installed, you have the option of running a CLI tool

    ## Example Globally installed usage
    ignore-bad-ts "node_modules/my-company-module/**"
    
    ## Example Per project usage
    yarn run ignore-bad-ts "node_modules/my-company-module/**"

In the above example, we are telling ignore-bad-ts to inject ts-ignore tags on all current files in the directory that match the glob "node_modules/my-company-module/**".

IMPORTANT on Unix systems, the shell may try to intercept the glob for you if you don't wrap your glob in "". If you do this, the script will not function as intended (feel free to debug the issue).

CLI if not global

Programmatic API

This package also provides programmatic methods for marking files as ignored programmatically.

ignoreFiles

This method is an async version that will find and modify all matching files.

ignoreFilesSync

This method will find and modify all matching files synchronously. This is not recommended, but is provided for when you are restricted to synchronous execution (like nextjs configs).

Arguments

Both functions generally match the argument signature of sync/stream from fast-glob.

There are a few differences:

1. Output options are not allowed from fast-glob (This would affect how the glob output is processed)
2. debug-glob - Use this to log all files that matched the globs. (Helpful for verifying your glob is doing what you think)
3. debug-ts - Use this to log all files that matched for writing @ts-nocheck. (Helpful for verifying only the ts files that should be written to)
4. dry-run - Use this to run the current command and view the logs but to not actually alter the files. (Helpful for quick debugging)

Recipes/Examples

NextJS config

If using NextJS, the strategy would be to synchronously call the ignore on your designated modules as your config file is instantiated.

// next.config.js
const { ignoreFilesSync } = require('ignore-bad-ts');

// Apply the ignore as we initialize this module, so nextJS can compile, etc.
ignoreFilesSync(['node_modules/my-company-module/**']);


module.exports = {
  webpack: (config, { buildId, dev, isServer, defaultLoaders, webpack }) => {
    // Important: return the modified config
    return config
  },
}

yarn command pre-command

You may want to simply add the cli command in scripts to ensure they build correctly.

Keep in mind, that you would need to apply this at every command that uses typechecking, since any new developer may run one command out of order with the other and fail to get a compilation.

In the below example, we assume that jest is using ts-jest, and so we also want to ignore-bad-ts when calling it.

// package.json
{
    ...,
    "scripts": {
        "build": "ignore-bad-ts node_modules/my-company-module/** && tsc",
        "test": "ignore-bad-ts node_modules/my-company-module/** && jest"
    },
    ...
}

Monorepo

Assuming that you've used something like lerna to setup a monorepo with packages/{package_name}, you may want to change the glob to point to the upper directory where node_modules is consolidated.

// packageA package.json
{
    ...,
    "scripts": {
        "build": "ignore-bad-ts ../../node_modules/my-company-module/** && tsc",
        "test": "ignore-bad-ts ../../node_modules/my-company-module/** && jest"
    },
    ...
}

Monorepo Programmatic Implementation

Assuming we have a package that is also a NextJS site, we can take advantage of the cwd command to set the directory we check for globs from.

// packageA next.config.js
const { ignoreFilesSync } = require('ignore-bad-ts');
const path = require('path');

// Apply the ignore as we initialize this module, so nextJS can compile, etc.
ignoreFilesSync(['node_modules/my-company-module/**'], { cwd: path.resolve(__dirname, '../..' });


module.exports = {
  webpack: (config, { buildId, dev, isServer, defaultLoaders, webpack }) => {
    // Important: return the modified config
    return config
  },
}

Development Notes

If you would like to test a feature or changes to this package, I highly recommend setting up a local verdaccio instance.