typescript-strictly-typed

TypeScript Strictly Typed

Enable configurations for strictly typed TypeScript, ESLint or TSLint, and optionally Angular. Because TypeScript strict mode is not enough.

A blog post explains the motivation of this lib.

Warning

Going fully strict is a choice to make at the very beginning of a project.

Enabling all strict options at once in an existing project is strongly discouraged, as hundred of errors would appear. Converting an existing project to full strict mode is still possible, but it should be done incrementally, by activating each option one by one.

Getting started

cd path/to/my-project
npx typescript-strictly-typed

npx is a command included in Node/npm. In case of problem (there is a known issue with npx on Windows if your user path contains a space, like C:\Users\Hello World), just do the full commands:

cd path/to/my-project
npm install typescript-strictly-typed -g
typescript-strictly-typed

What does it do?

Adding configuration for:

• TypeScript compiler options
  • strict (which includes in particular noImplicitAny and strictNullChecks)
  • noFallthroughCasesInSwitch
  • noImplicitReturns
  • noPropertyAccessFromIndexSignature
  • forceConsistentCasingInFileNames
• ESLint rules
  • @typescript-eslint/no-explicit-any
  • @typescript-eslint/explicit-module-boundary-types
• TSLint rules
  • no-any
  • typedef with call-signature
• Angular compiler options
  • strictInjectionParameters
  • strictTemplates
  • strictInputAccessModifiers
• Angular ESLint options
  • @angular-eslint/template/no-any
• Angular Codelyzer lint options
  • template-no-any

By the same author

• Angular schematics extension for VS Code (GUI for Angular CLI commands)
• @ngx-pwa/local-storage: Angular library for local storage
• Popular Angular posts on Medium
• Follow updates of this lib on Twitter
• Angular onsite trainings (based in Paris, so the website is in French, but my English bio is here and I'm open to travel)

My open source contributions are done on free time. So if your company earns money with them, it would be nice to consider becoming a sponsor.

Requirements

Node & npm

You need a LTS version of Node and npm, ie. currently:

• Node >= 10.13
• npm >= 6.4

Directory

Be sure to invoke the command in the root directory of your project, ie. where your configuration files (like tsconfig.json) are located.

TypeScript

strict mode is available in TypeScript >= 2.3.

ESLint

ESLint must be configured for TypeScript, ie. with:

• "parser": "@typescript-eslint/parser" and "plugins": ["@typescript-eslint"]
• or an equivalent (for example Vue uses "extends": ["@vue/typescript"] and React uses "extends": "react-app")

Official getting started documentation of @typescript-eslint

Angular

The project must use a LTS version of Angular CLI, ie. with a angular.json file.

Known limitations

This lib is here to promote good practices. But at the end of the day, it just adds a few lines in configuration files, as explained above in "What does it do?".

It was already a lot of work to support all possible official configuration formats. So if it doesn't work for your project because of a custom configuration, you can just modify the configuration files yourself.

Apps using .eslintrc.js (including Vue)

If your project uses a .eslintrc.js file (instead of a more classic .eslintrc.json file) you'll have to copy the strict rules newly generated in .eslintrc.json file into the existing .eslintrc.js file.

For Vue apps created with vue create, after running this lib command, it will work out of the box if you chose one of the following Vue options:

• ESLint with config stored in package.json
• TSLint

But if you chose ESLint with a dedicated config file, Vue will create a .eslintrc.js file and so you'll have to do the above step.

See issue #3 if you want to help.

Changelog

Changelog available here.

License

MIT

Changelog

2.8.0 (2021-04-19)

Features

For ESLint:

• add @typescript-eslint/explicit-module-boundary-types instead of @typescript-eslint/explicit-function-return-type
• preserve advanced options if rules already exist
• do not add TypeScript rules twice if already done in an override