ESLint configuration for Javascript and TypeScript based SparkPost projects

There were several breaking changes including moving from ESLint 5.x to ESLint 8.x. This change alone caused some minimal breaking changes. Since we ultimately extend eslint:recommended in our base configuration, the upgrade from eslint 5.x to 8.x changed that 'recommended' config and the rules between versions have definitely changed. We compensated to match our existing config as best we could, but you may find other changes when running ESLint in your projects.

We also moved several specific configs from overrides in the base config to their own specific configs. Mocha and TypeScript are used by some projects, however they are not used by every project so we have separated them to their own configs and moved their dependencies to optional peer dependencies so that we no longer need to install and maintain them in projects that don't use them.

Traditionally we've setup special rules for mocha based projects, however not all projects use mocha. This would lead to dependencies being installed that were unrelated to the project. For this reason, we have split mocha configuration into its own configuration. You can take advantage of it by extending sparkpost/mocha from this package. This will require you to install the plugin eslint-plugin-mocha in the project's dev dependencies.

Example:

npm i -D eslint-plugin-mocha

In your .eslintrc file:

{
  "normal": "stuff <- comment",
  "overrides": [
    {
      "files": ["test/**/*.spec.js"],
      "extends": ["sparkpost/mocha"]
    }
  ]
}

We have several typescript based projects, however not all projects use typescript. This would lead to dependencies being installed that were unrelated to the project. For this reason, we have split typescript configuration into its own configuration. You can take advantage of it by extending sparkpost/typescript from this package. This will require you to install several plugins and configs in the project's dev dependencies.

Example:

npm i -D @typescript-eslint/eslint-plugin @typescript-eslint/parser eslint-config-prettier eslint-plugin-prettier

In your .eslintrc file:

{
  "normal": "stuff <- comment",
  "extends": ["sparkpost/typescript"],
  "rules": {
    "other": "rules that override the base typescript config <- comment"
  }
}

This config has extra rules specifically around JSDocs to help have better documentation in our libraries.
This can help in knowledge sharing and will hopefully promote better docs in our shared JS modules.

To use, add the following to your .eslintrc file:

{
  "extends": "sparkpost/lib"
}

{
  "chk-changelog": "grep `node -e 'console.log(require(\"./package.json\").version);'` CHANGELOG.md || echo 'Please update CHANGELOG.md with your updates'; exit 255",
  "prepublishOnly": "npm run chk-changelog"
}

This will check your changelog for an entry for your current version when you publish.