Setup eslint

.eslintignore

@@ -0,0 +1,8 @@
+**/_actual.js
+**/expected.js
+_output
+test/*/samples/*/output.js
+node_modules
+__sapper__
+/runtime/app.mjs
+/runtime/server.mjs

.eslintrc.js

@@ -0,0 +1,78 @@
+module.exports = {
+	root: true,
+	rules: {
+		indent: 'off',
+		'no-unused-vars': 'off',
+		semi: [2, 'always'],
+		'keyword-spacing': [2, { before: true, after: true }],
+		'space-before-blocks': [2, 'always'],
+		'no-mixed-spaces-and-tabs': [2, 'smart-tabs'],
+		'no-cond-assign': 0,
+		'object-shorthand': [2, 'always'],
+		'no-const-assign': 2,
+		'no-class-assign': 2,
+		'no-this-before-super': 2,
+		'no-var': 2,
+		'no-unreachable': 2,
+		'valid-typeof': 2,
+		'quote-props': [2, 'as-needed'],
+		'one-var': [2, 'never'],
+		'prefer-arrow-callback': 2,
+		'prefer-const': [2, { destructuring: 'all' }],
+		'arrow-spacing': 2,
+		'no-inner-declarations': 0,
+		'require-atomic-updates': 'off',
+		'@typescript-eslint/indent': 'off',
+		'@typescript-eslint/camelcase': 'off',
+		'@typescript-eslint/no-use-before-define': 'off',
+		'@typescript-eslint/array-type': ['error', 'array-simple'],
+		'@typescript-eslint/explicit-function-return-type': 'off',
+		'@typescript-eslint/no-explicit-any': 'off',
+		'@typescript-eslint/explicit-member-accessibility': 'off',
+		'@typescript-eslint/no-unused-vars': [
+			'error',
+			{
+				argsIgnorePattern: '^_'
+			}
+		],
+		'@typescript-eslint/no-object-literal-type-assertion': 'off',
+		'@typescript-eslint/no-unused-vars': 'off',
+		'@typescript-eslint/prefer-interface': 'off'
+	},
+	globals: {
+		globalThis: false
+	},
+	env: {
+		es6: true,
+		browser: true,
+		node: true,
+		mocha: true
+	},
+	extends: [
+		'eslint:recommended',
+		'plugin:import/errors',
+		'plugin:import/warnings',
+		'plugin:import/typescript',
+		'plugin:@typescript-eslint/recommended'
+	],
+	parserOptions: {
+		ecmaVersion: 9,
+		sourceType: 'module'
+	},
+	plugins: ['svelte3'],
+	overrides: [
+		{
+			files: ['*.js'],
+			rules: {
+				'@typescript-eslint/no-var-requires': 'off'
+			}
+		},
+		{
+			files: ['*.svelte'],
+			processor: 'svelte3/svelte3',
+			rules: {
+				'@typescript-eslint/indent': 'off'
+			}
+		}
+	]
+};

.github/workflows/ci.yml

@@ -17,10 +17,9 @@ jobs:
     - run: npm test
       env:
         CI: true
- # Uncomment with https://github.com/sveltejs/sapper/pull/1198
-#  Lint:
-#    runs-on: ubuntu-latest
-#    steps:
-#    - uses: actions/checkout@v2
-#    - uses: actions/setup-node@v1
-#    - run: 'npm i && npm run lint'
+  Lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-node@v1
+    - run: 'npm i && npm run lint'