feat: initial rules

.eslintignore

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+!.eslintrc.js
+coverage
+lib

.eslintrc.js

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+/** @type {import('eslint').Linter.Config} */
+const config = {
+  root: true,
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: 'tsconfig.json',
+    ecmaVersion: 2019,
+    sourceType: 'module'
+  },
+  env: { node: true },
+  plugins: ['eslint-plugin'],
+  extends: ['ackama', 'ackama/@typescript-eslint'],
+  ignorePatterns: ['!.eslintrc.js', 'coverage', 'lib'],
+  overrides: [
+    {
+      files: ['test/**'],
+      extends: ['ackama/jest'],
+      rules: {
+        'jest/prefer-expect-assertions': 'off'
+      }
+    }
+  ],
+  rules: {
+    'import/no-deprecated': 'error',
+    '@typescript-eslint/no-unsafe-assignment': 'error',
+    '@typescript-eslint/prefer-reduce-type-parameter': 'error'
+  }
+};
+
+module.exports = config;

.gitattributes

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+* text eol=lf

.github/eslint-compact.json

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+{
+  "problemMatcher": [
+    {
+      "owner": "eslint-compact",
+      "pattern": [
+        {
+          "regexp": "^(.+):\\sline\\s(\\d+),\\scol\\s(\\d+),\\s(Error|Warning|Info)\\s-\\s(.+)\\s\\((.+)\\)$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "severity": 4,
+          "message": 5,
+          "code": 6
+        }
+      ]
+    }
+  ]
+}

.github/eslint-stylish.json

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+{
+  "problemMatcher": [
+    {
+      "owner": "eslint-stylish",
+      "pattern": [
+        {
+          "regexp": "^([^\\s].*)$",
+          "file": 1
+        },
+        {
+          "regexp": "^\\s+(\\d+):(\\d+)\\s+(error|warning|info)\\s+(.*)\\s\\s+(.*)$",
+          "line": 1,
+          "column": 2,
+          "severity": 3,
+          "message": 4,
+          "code": 5,
+          "loop": true
+        }
+      ]
+    }
+  ]
+}

.github/workflows/checks.yaml

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+name: Checks
+on:
+  push:
+    branches:
+      - master
+      - next
+  pull_request:
+    branches:
+      - master
+      - next
+
+env:
+  # reduces noise from npm post-install scripts
+  DISABLE_OPENCOLLECTIVE: true
+  OPEN_SOURCE_CONTRIBUTOR: true
+
+jobs:
+  commitlint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Commit Linter
+        uses: wagoid/[email protected]
+        with:
+          configFile: './package.json'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  test-node:
+    name:
+      # prettier-ignore
+      Test on Node.js v${{ matrix.node-version }} and eslint v${{matrix.eslint-version }}
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version: [8.x, 10.x, 12.x, 13.x, 14.x]
+        eslint-version: [6, 7]
+        exclude:
+          # eslint@7 doesn't support node@8
+          - node-version: 8.x
+            eslint-version: 7
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+      - name: install with eslint v${{matrix.eslint-version }}
+        run: |
+          npm ci
+          npm install -D eslint@${{matrix.eslint-version }}
+      - name: prettylint
+        run: npm run prettylint
+      - name: typecheck
+        run: npm run typecheck
+      - name: test
+        run: npm run test --coverage
+        env:
+          CI: true
+
+  test-os:
+    name: Test on ${{ matrix.os }} using Node.js LTS
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+      - name: install
+        run: npm ci
+      - name: prettylint
+        run: npm run prettylint
+      - name: typecheck
+        run: npm run typecheck
+      - name: test
+        run: npm run test --coverage
+        env:
+          CI: true

.github/workflows/release.yaml

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+name: Release
+on:
+  push:
+    branches:
+      - master
+
+env:
+  # reduces noise from npm post-install scripts
+  DISABLE_OPENCOLLECTIVE: true
+  OPEN_SOURCE_CONTRIBUTOR: true
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: '12.x'
+
+      - uses: actions/cache@v1
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+
+      - name: install
+        run: npm ci
+      - name: prettylint
+        run: npm run prettylint
+      - name: typecheck
+        run: npm run typecheck
+      - name: test
+        run: npm run test --coverage
+        env:
+          CI: true
+
+      - name: release
+        run: npm run release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.huskyrc.json

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+{
+  "$schema": "http://json.schemastore.org/huskyrc",
+  "hooks": {
+    "commit-msg": "commitlint -e $HUSKY_GIT_PARAMS",
+    "pre-commit": "lint-staged"
+  }
+}

.lintstagedrc.json

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+{
+  "**/*.{t,j}s": "eslint --fix",
+  "**/.eslint{rc,ignore}": "npm run lint",
+  "**/*.{md,json}": "prettier --write"
+}

README.md

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+<div align="center">
+  <a href="https://eslint.org/">
+    <img
+      width="150"
+      height="150"
+      src="https://eslint.org/assets/img/logo.svg"
+      alt="ESLint Logo"
+    />
+  </a>
+  <h1>eslint-plugin-eslint-config</h1>
+  <p>ESLint plugin for ESLint configs</p>
+</div>
+
+This plugin provides rules for linting files that export configs meant for use
+with ESLint, to ensure that they're valid.
+
+## Installation
+
+    npm install --dev eslint eslint-plugin-eslint-config
+
+**Note:** If you installed ESLint globally then you must also install
+`eslint-plugin-eslint-config` globally.
+
+## Usage
+
+Add `config` to the plugins section of your `.eslintrc.js` configuration file.
+You can omit the `eslint-plugin-` prefix:
+
+```json
+{
+  "plugins": ["eslint-config"]
+}
+```
+
+Then configure the rules you want to use _for your config(s)_ using `overrides`:
+
+```json
+{
+  "overrides": [
+    {
+      "files": [".eslintrc.js", "react.js", "@typescript-eslint.js"],
+      "rules": {
+        "eslint-config/no-deprecated-rules": "warn"
+      }
+    }
+  ]
+}
+```
+
+The rules assume that the files they're linting are configs meant for ESLint.
+
+## Shareable configurations
+
+This plugin provides three presets:
+
+- `recommended-rules`
+- `rc`
+- `all`
+
+The `rc` preset generally should be used by all projects, as it applies
+recommended rules to supported eslintrc files.
+
+If a project contains other files that export eslint configs (such as an eslint
+config package), the `recommended-rules` preset can be used to apply the
+recommended rules to those files using `overrides`.
+
+<!-- The reason behind having two presets instead of the standard `recommended`
+preset is because the rules provided by this plugin work by executing the source
+code that they're linting to capture the configuration they export that gets
+used by eslint.
+
+This means that they can trigger side effects in the same way importing a file
+might, and so should not be applied to every file in a code base.
+
+To facilitate this ESLint allows configs to provide an `overrides` property that
+applies rules to files based on globs (which is what `eslint-config/rc` does),
+but while shared configs can use `overrides` there isn't a way to nicely to add
+to the glob patterns to reuse the rules. -->
+
+While the `recommended` and `rc` configurations only change in major versions,
+the `all` configuration may change in any release and is thus unsuited for
+installations requiring long-term consistency.
+
+## Rules
+
+<!-- begin rules list -->
+
+| Rule                                                     | Description                                         | Configurations   | Fixable      |
+| -------------------------------------------------------- | --------------------------------------------------- | ---------------- | ------------ |
+| [no-deprecated-rules](docs/rules/no-deprecated-rules.md) | Checks for usage of deprecated eslint rules         | ![recommended][] |              |
+| [no-invalid-config](docs/rules/no-invalid-config.md)     | Checks that the config exported by a file is valid  | ![recommended][] |              |
+| [no-unknown-rules](docs/rules/no-unknown-rules.md)       | Ensures that all rules are known                    | ![recommended][] |              |
+| [sort-rules](docs/rules/sort-rules.md)                   | Ensures that rules are sorted in a consistent order |                  | ![fixable][] |
+
+<!-- end rules list -->
+
+[recommended]: https://img.shields.io/badge/-recommended-lightgrey.svg
+[fixable]: https://img.shields.io/badge/-fixable-green.svg

babel.config.js

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+'use strict';
+
+// todo: https://github.com/babel/babel/issues/8529 :'(
+module.exports = {
+  plugins: ['replace-ts-export-assignment'],
+  presets: [
+    '@babel/preset-typescript',
+    ['@babel/preset-env', { targets: { node: 8 } }]
+  ]
+};

docs/rules/no-deprecated-rules.md

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+# Checks for usage of deprecated eslint rules (`no-deprecated-rules`)
+
+## Rule details
+
+This rule checks for rules that have been marked as deprecated, and suggests
+their replacements, if any.
+
+Note that this rule, like others of its kind, works by mapping the results of
+running the configs through ESLint to rule ids, and then checking every object
+property in the file being linted against these rule ids.
+
+This means that if a deprecated rule is used anywhere in the exported config,
+then _all_ the places that rule id is used be highlighted.
+
+For example:
+
+```js
+const rules = {
+  '@typescript-eslint/camelcase': 'warn'
+};
+
+module.exports = {
+  plugins: ['@typescript-eslint'],
+  overrides: [
+    {
+      files: ['*.tsx'],
+      rules: {
+        '@typescript-eslint/camelcase': 'off'
+      }
+    }
+  ],
+  rules: {
+    '@typescript-eslint/camelcase': 'error'
+  }
+};
+```
+
+In the above configuration, all three `'@typescript-eslint/camelcase'`
+properties would be marked.