Introduce official standardjs preset for consumption by create CLI (n…

…eutrinojs#453)

package.json

@@ -16,9 +16,10 @@
   "scripts": {
     "validate:eslintrc:root": "eslint --no-eslintrc --print-config . -c ./.eslintrc.js > /dev/null",
     "validate:eslintrc:eslint": "eslint --no-eslintrc --print-config . -c ./packages/eslint/eslintrc.js > /dev/null",
-    "validate:eslintrc:airbnb-base": "eslint --no-eslintrc --print-config . -c ./packages/airbnb-base/eslintrc.js > /dev/null",
     "validate:eslintrc:airbnb": "eslint --no-eslintrc --print-config . -c ./packages/airbnb/eslintrc.js > /dev/null",
-    "validate:eslintrc": "yarn validate:eslintrc:eslint && yarn validate:eslintrc:airbnb-base && yarn validate:eslintrc:airbnb && yarn validate:eslintrc:root",
+    "validate:eslintrc:airbnb-base": "eslint --no-eslintrc --print-config . -c ./packages/airbnb-base/eslintrc.js > /dev/null",
+    "validate:eslintrc:standardjs": "eslint --no-eslintrc --print-config . -c ./packages/standardjs/eslintrc.js > /dev/null",
+    "validate:eslintrc": "yarn validate:eslintrc:eslint && yarn validate:eslintrc:airbnb-base && yarn validate:eslintrc:airbnb && yarn validate:eslintrc:standardjs && yarn validate:eslintrc:root",
     "lint": "node packages/neutrino/bin/neutrino lint",
     "changelog": "auto-changelog --remote upstream --commit-limit false",
     "docs:build": "gitbook build && cp CNAME _book",

packages/standardjs/.npmignore

@@ -0,0 +1,2 @@
+/test/
+eslintrc.js

packages/standardjs/README.md

@@ -0,0 +1,318 @@
+# Neutrino StandardJS Preset
+
+`@neutrinojs/standardjs` is a Neutrino preset that supports linting JavaScript projects with the
+[StandardJS ESLint config](https://standardjs.com).
+
+[![NPM version][npm-image]][npm-url]
+[![NPM downloads][npm-downloads]][npm-url]
+[![Join the Neutrino community on Spectrum][spectrum-image]][spectrum-url] 
+
+## Features
+
+- Zero upfront configuration necessary to start linting your project with StandardJS
+- Modern Babel knowledge supporting ES modules, Web and Node.js apps
+- Highly visible during development, fails compilation when building for production
+- Easily extensible to customize your project as needed
+
+## Requirements
+
+- Node.js v6.10+
+- Yarn or npm client
+- Neutrino v7, Neutrino build preset
+
+## Installation
+
+`@neutrinojs/standardjs` can be installed via the Yarn or npm clients. Inside your project, make sure
+`neutrino` and `@neutrinojs/standardjs` are development dependencies. You will also be using
+another Neutrino preset for building your application source code.
+
+#### Yarn
+
+```bash
+❯ yarn add --dev @neutrinojs/standardjs
+```
+
+#### npm
+
+```bash
+❯ npm install --save-dev @neutrinojs/standardjs
+```
+
+## Project Layout
+
+`@neutrinojs/standardjs` follows the standard [project layout](https://neutrino.js.org/project-layout) specified by Neutrino. This
+means that by default all project source code should live in a directory named `src` in the root of the
+project.
+
+## Quickstart
+
+After adding the StandardJS preset to your Neutrino-built project, edit your project's package.json to add the preset for
+linting **before** your build preset. For example, if you are building your project using `@neutrinojs/web`:
+
+```json
+{
+  "scripts": {
+    "start": "neutrino start --use @neutrinojs/standardjs @neutrinojs/web",
+    "build": "neutrino build --use @neutrinojs/standardjs @neutrinojs/web"
+  }
+}
+```
+
+Or if you are using a `.neutrinorc.js`, add this preset to your use array instead of `--use` flags:
+
+```js
+module.exports = {
+  use: [
+    '@neutrinojs/standardjs',
+    '@neutrinojs/web'
+  ]
+};
+```
+
+Start the app, then check your console for any linting errors. If everything is successful, you should see no errors in
+the console. ESLint errors visible during development are reported, but will still continue to build and serve your
+project. ESLint errors during build will not build the project, and will cause the command to fail.
+
+#### Yarn
+
+```bash
+❯ yarn start
+
+✔ Development server running on: http://localhost:5000
+✔ Build completed
+
+ERROR in ./src/index.js
+
+/web/src/index.js
+  7:1   warning  Unexpected console statement                no-console
+  7:14  error    A space is required after '{'               babel/object-curly-spacing
+  7:20  error    Missing space before value for key 'hello'  key-spacing
+  7:27  error    A space is required before '}'              babel/object-curly-spacing
+
+✖ 4 problems (3 errors, 1 warning)
+```
+
+#### npm
+
+```bash
+❯ npm start
+
+✔ Development server running on: http://localhost:5000
+✔ Build completed
+
+ERROR in ./src/index.js
+
+/web/src/index.js
+  7:1   warning  Unexpected console statement                no-console
+  7:14  error    A space is required after '{'               babel/object-curly-spacing
+  7:20  error    Missing space before value for key 'hello'  key-spacing
+  7:27  error    A space is required before '}'              babel/object-curly-spacing
+
+✖ 4 problems (3 errors, 1 warning)
+```
+
+## Building
+
+`@neutrinojs/standardjs` will cause errors to **fail your build** when creating a bundle via `neutrino build`. If
+you want to ease introduction of this linting preset to your project, consider only adding it to your use list for
+`neutrino start` or `development` environment until all linting errors have been resolved.
+
+```bash
+❯ yarn build
+
+
+/web/src/index.js
+  6:1   warning  Unexpected console statement            no-console
+  6:14  error    A space is required after '{'           babel/object-curly-spacing
+  6:16  error    Missing space before value for key 'a'  key-spacing
+  6:17  error    A space is required before '}'          babel/object-curly-spacing
+
+✖ 4 problems (3 errors, 1 warning)
+
+error Command failed with exit code 1.
+```
+
+_Example: ease linting into project by only adding when `NODE_ENV=development`, e.g. `neutrino start`:_
+
+```js
+module.exports = {
+  use: [
+    '@neutrinojs/web'
+  ],
+  env: {
+    NODE_ENV: {
+      development: {
+        use: ['@neutrinojs/standardjs']
+      }
+    }
+  }
+};
+```
+
+## Middleware options
+
+This preset uses the same middleware options as [@neutrinojs/eslint](https://neutrino.js.org/packages/eslint).
+If you wish to customize what is included, excluded, or any ESLint options, you can provide an options object with the
+middleware and this will be merged with our internal defaults for this preset. Use an array pair instead of a string
+to supply these options.
+
+_Example: Turn on semicolons as being required, as opposed to the StandardJS rules._
+
+```js
+module.exports = {
+  use: [
+    ['@neutrinojs/standardjs', {
+      eslint: {
+        rules: {
+          semi: 'error'
+        }
+      }
+    }]
+  ]
+};
+```
+
+## Customizing
+
+To override the build configuration, start with the documentation on [customization](https://neutrino.js.org/customization).
+`@neutrinojs/standardjs` creates some conventions to make overriding the configuration easier once you are ready to
+make changes.
+
+### Rules
+
+The following is a list of rules and their identifiers which can be overridden:
+
+| Name | Description | Environments and Commands |
+| --- | --- | --- |
+| `lint` | Lints JS and JSX files from the `src` directory using ESLint. Contains a single loader named `eslint`. This is inherited from `@neutrinojs/eslint`. | all |
+
+### Information
+
+If you want your preset or middleware to also extend from another **ESLint configuration or preset** that you have made
+a dependency, you must use `baseConfig.extends` rather than just `extends`. This is a limitation of ESLint, not this
+middleware.
+
+### Override configuration
+
+By following the [customization guide](https://neutrino.js.org/customization) and knowing the rule and loader IDs above,
+you can also override or augment the build by providing a function to your `.neutrinorc.js` use array. You can also
+make this change from the Neutrino API when using the `use` method.
+
+_Example: Turn on semicolons as being required, as opposed to the StandardJS rules, from `.neutrinorc.js` using a function and the API:_
+
+```js
+module.exports = {
+  use: [
+    '@neutrinojs/standardjs',
+    (neutrino) => neutrino.config.module
+      .rule('lint')
+      .use('eslint')
+      .tap(options => Object.assign({}, options, {
+        rules: {
+          semi: 'error'
+        }
+      }))
+  ]
+};
+```
+
+## eslint CLI
+
+_This is the recommended way to perform a one-off lint in a Neutrino project, and is inherited from @neutrinojs/eslint._
+
+You can also have Neutrino invoke ESLint for you if you wish to perform a one-time lint. This avoids needing to install
+ESLint manually, creating a `.eslintrc.js` file, or having to manage includes and ignores. As long as the ESLint
+middleware is loaded, you have access to a command to run ESLint from the command line.
+
+This middleware registers a command named `lint` which programmatically calls ESLint and prints the results to
+the console.
+
+```bash
+❯ neutrino lint
+```
+
+```bash
+❯ neutrino lint --fix
+```
+
+## eslintrc Config
+
+If you cannot or do not wish to use Neutrino to execute one-off linting, you can still use ESLint manually.
+
+`@neutrinojs/eslint`, from which this preset inherits, also provides a method for getting the ESLint
+configuration suitable for use in an eslintrc file. Typically this is used for providing hints or fix solutions to the
+development environment, e.g. IDEs and text editors. Doing this requires
+[creating an instance of the Neutrino API](https://neutrino.js.org/api) and providing the middleware it uses. If you keep all
+this information in a `.neutrinorc.js`, this should be relatively straightforward. By providing all the middleware used
+to Neutrino, you can ensure all the linting options used across all middleware will be merged together for your
+development environment, without the need for copying, duplication, or loss of organization and separation.
+
+This middleware registers another command named `eslintrc` which returns an ESLint configuration object suitable for
+consumption by the ESLint CLI. Use the Neutrino API's `call` method to invoke this command:
+
+_Example: Create a .eslintrc.js file in the root of the project, using `.neutrinorc.js` middleware._
+
+```js
+// .eslintrc.js
+
+// If you do not specify any middleware to call(),
+// it will use the local .neutrinorc.js file
+
+const { Neutrino } = require('neutrino');
+
+module.exports = Neutrino().call('eslintrc');
+```
+
+_Example: Create a .eslintrc.js file in the root of the project, using specified middleware._
+
+```js
+// .eslintrc.js
+const { Neutrino } = require('neutrino');
+
+module.exports = Neutrino().call('eslintrc', [
+  ['@neutrinojs/standardjs', {
+    eslint: {
+      rules: { semi: 'error' }
+    }
+  }],
+  '@neutrinojs/react'
+]);
+```
+
+If you are able, only use a `.eslintrc.js` file for editor hints, and use the Neutrino `lint` command for one-off linting
+or fixes.
+
+Projects may face a problem when their editor or IDE lints all files and highlights errors that were normally excluded
+from source, i.e. Neutrino's `include` and `exclude` options. This is because the ESLint CLI does not have a way to
+specify included and excluded files from configuration. If you still wish to use ESLint's CLI for linting, consider
+setting [CLI flags](http://eslint.org/docs/user-guide/command-line-interface#options) or using an
+[eslintignore](http://eslint.org/docs/user-guide/configuring#ignoring-files-and-directories) to choose which files to
+include or exclude from linting.
+
+Unfortunately ESLint does not provide the possibility to configure ignored paths from Neutrino configuration and exclude them
+from linting. Projects authors should define this manually in their project root directory in a `.eslintignore` file. This
+is one of the main reasons to prefer using the `lint` CLI command with this middleware, as it avoids a lot of manual
+configuration and boilerplate.
+
+`.eslintignore` file:
+
+```
+/build
+/*.*
+```
+
+ESLint will exclude built files and any files in the root directory (e.g. custom Neutrino configuration) but `src` and
+`test` folders will be still checked. `node_modules` are ignored by default in ESLint. More information can be found
+in the [ESLint user guide](http://eslint.org/docs/user-guide/configuring#ignoring-files-and-directories).
+
+## Contributing
+
+This preset is part of the [neutrino-dev](https://github.com/mozilla-neutrino/neutrino-dev) repository, a monorepo
+containing all resources for developing Neutrino and its core presets and middleware. Follow the
+[contributing guide](https://neutrino.js.org/contributing) for details.
+
+[npm-image]: https://img.shields.io/npm/v/@neutrinojs/standardjs.svg
+[npm-downloads]: https://img.shields.io/npm/dt/@neutrinojs/standardjs.svg
+[npm-url]: https://npmjs.org/package/@neutrinojs/standardjs
+[spectrum-image]: https://withspectrum.github.io/badge/badge.svg
+[spectrum-url]: https://spectrum.chat/neutrino

packages/standardjs/eslintrc.js

@@ -0,0 +1,4 @@
+const { Neutrino } = require('../neutrino');
+
+// eslint-disable-next-line global-require
+module.exports = Neutrino({ cwd: __dirname }).call('eslintrc', [require('.')]);

packages/standardjs/index.js

@@ -0,0 +1,26 @@
+const lint = require('@neutrinojs/eslint');
+const merge = require('deepmerge');
+
+module.exports = (neutrino, opts = {}) => {
+  neutrino.use(lint, merge.all([
+    {
+      eslint: {
+        baseConfig: {
+          extends: ['standard']
+        },
+        plugins: ['standard'],
+        rules: {
+          // handled by babel rules
+          'new-cap': 'off',
+          // handled by babel rules
+          'object-curly-spacing': 'off',
+          // require a capital letter for constructors
+          'babel/new-cap': ['error', { newIsCap: true }],
+          // require padding inside curly braces
+          'babel/object-curly-spacing': ['error', 'always']
+        }
+      }
+    },
+    opts
+  ]));
+};

packages/standardjs/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@neutrinojs/standardjs",
+  "version": "7.3.2",
+  "description": "Neutrino preset for linting projects using the StandardJS ESLint config",
+  "main": "index.js",
+  "keywords": [
+    "neutrino",
+    "neutrino-preset",
+    "standardjs",
+    "standard",
+    "eslint"
+  ],
+  "author": "Eli Perelman <eli@eliperelman.com>",
+  "license": "MPL-2.0",
+  "repository": "https://github.com/mozilla-neutrino/neutrino-dev/tree/master/packages/standardjs",
+  "homepage": "https://neutrino.js.org",
+  "bugs": "https://github.com/mozilla-neutrino/neutrino-dev/issues",
+  "dependencies": {
+    "@neutrinojs/eslint": "^7.3.2",
+    "deepmerge": "^1.5.2",
+    "eslint-config-standard": "^10.2.1",
+    "eslint-plugin-import": "^2.8.0",
+    "eslint-plugin-node": "^5.2.1",
+    "eslint-plugin-promise": "^3.6.0",
+    "eslint-plugin-standard": "^3.0.1"
+  },
+  "peerDependencies": {
+    "neutrino": "^7.0.0"
+  }
+}