Typescript strict mode plugin

Typescript plugin that allows turning on strict mode in specific files or directories.

Do i need this plugin?

This plugin was created for bigger repositories that want to incorporate typescript strict mode, but project is so big that refactoring everything would take ages. This plugin allows user to simply put //@ts-strict comment to a top of a file and turn a strict mode to that file. If needed, strict mode can be turned on to directories too. NOTE: this plugin doesn't work in compile time. It will show errors in your IDE but they won't appear during compilation.

How to install

Use npm:

npm i --save-dev typescript-strict-plugin

or yarn

yarn add -D typescript-strict-plugin

and add plugin to your tsconfig.json:

{
 "compilerOptions": {
   ...
   "strict": false,
   "plugins": [
    {
     "name": "typescript-strict-plugin"
    }
   ]
 }
}

That's it! You should be able to use @ts-strict comment to strictly check your files.

Configuration

Plugin takes one extra non mandatory argument paths that is an array of relative or absolute paths of directories that should be included.

{
  "compilerOptions": {
    ...
    "strict": false,
    "plugins": [
      {
        "name": "typescript-strict-plugin",
        "paths": [
          "./src",
          "/absolute/path/to/source/"
        ]
      }
    ]
  }
}

All files contained in those paths will be be strictly checked. Yay!

Examples

Let's consider this type and a variable

interface TestType {
   bar: string;
}

const foo: TestType | undefined = undefined;

1. No paths argument With tsconfig.json like this:

{
  "compilerOptions": {
    ...
    "strict": false,
    "plugins": [
      {
        "name": "typescript-strict-plugin"
      }
    ]
  }
}

Typescript will produce errors:

//@ts-strict
...
const boo = foo.bar; // TS2532: Object is possibly 'undefined'.

Or not, depending on whether we used ts-strict or not:

//no strict comment here
...
const boo = foo.bar; // no error here

2. With paths argument With tsconfig.json like this:

{
  "compilerOptions": {
    ...
    "strict": false,
    "plugins": [
      {
        "name": "typescript-strict-plugin",
         "path": "./src"
      }
    ]
  }
}

If file is in the directory typescript will produce errors even if ts-strict comment is not in the file :

// ./src/index.ts
const boo = foo.bar; // TS2532: Object is possibly 'undefined'.

If file is not in the diretory there will be no error

// ./lib/index.ts
const boo = foo.bar; // no error here

If file is not in the diretory but there is ts-strict file will be check with strict mode:

// ./lib/index.ts
//@ts-strict
...
const boo = foo.bar; // TS2532: Object is possibly 'undefined'. 

Testing the plugin

Manually

run

npm i

inside root folder and sample-project folder and then run

npm run build

or

npm run dev

and restart typescript service inside sample-project. Files in sample-project folder should use a local plugin. After you made changes to a plugin you should probably restart typescript service in order to reload the plugin.

E2E tests

In order to run e2e tests run

npm run build && npm run e2e

Contributing

Feel free to create PR's and issues.