.eslintrc.js

const isProduction = process.env.NODE_ENV === 'production';

/**
 * @type {import('@types/eslint').Linter.Config}
 */
module.exports = {
    root: true,
    parser: 'vue-eslint-parser',
    env: {
        node: true,
        browser: true,
        es6: true,
    },
    extends: [
        'eslint:recommended',
        'plugin:@typescript-eslint/recommended',
        'plugin:@typescript-eslint/recommended-requiring-type-checking',
        'plugin:vue/vue3-recommended',
        '@vue/typescript/recommended',
    ],
    plugins: [
        '@typescript-eslint',
        'vue'
    ],
    ignorePatterns: [
        'node_modules',
        '*.js'
    ],
    parserOptions: {
        ecmaVersion: 2020,
        parser: '@typescript-eslint/parser',
        sourceType: 'module',
        project: './tsconfig.eslint.json',
        tsconfigRootDir: __dirname,
        extraFileExtensions: ['.vue'],
    },
    globals: {
        __VUEISH_VERSION__: 'readonly',
        globalThis: 'readonly',
    },
    rules: {
        // https://eslint.org/docs/rules/
        'no-console': isProduction ? 'error': 'warn',
        'no-debugger': isProduction ? 'error' : 'warn',
        'semi': 'off',
        'indent': 'off',
        'no-unused-expressions': 'off',
        'space-before-function-paren': ['warn', {
            'anonymous': 'never',
            'named': 'never',
            'asyncArrow': 'always'
        }],
        'no-trailing-spaces': 'warn',
        'no-any': 'off',
        'no-prototype-builtins': 'off',
        'no-unused-vars': 'off',
        'prefer-rest-params': 'warn',
        'no-extra-parens': 'off',
        'quotes': 'off',
        'func-call-spacing': 'off',
        'comma-spacing': 'off',
        'keyword-spacing': 'off',
        'object-curly-spacing': ['warn', 'always'],
        'comma-dangle': ['warn', 'never'],
        'max-len': ['warn', 120],
        'eqeqeq': 'error',

        // https://github.com/typescript-eslint/typescript-eslint/tree/master/packages/eslint-plugin#supported-rules
        '@typescript-eslint/indent': ['warn', 4],
        '@typescript-eslint/semi': 'error',
        '@typescript-eslint/no-unused-expressions': ['error', {
            allowTernary: true,
            allowShortCircuit: true
        }],
        '@typescript-eslint/quotes': ['warn', 'single'],
        '@typescript-eslint/no-extra-parens': 'error',
        '@typescript-eslint/no-unused-vars': 'warn',
        '@typescript-eslint/no-useless-constructor': 'warn',
        '@typescript-eslint/no-explicit-any': 'off',
        '@typescript-eslint/ban-ts-comment': 'warn',
        '@typescript-eslint/no-unsafe-return': 'off',
        '@typescript-eslint/no-unsafe-assignment': 'off',
        '@typescript-eslint/explicit-module-boundary-types': ['error', {
            allowArgumentsExplicitlyTypedAsAny: true,
            allowedNames: ['setup']
        }],
        '@typescript-eslint/prefer-nullish-coalescing': 'warn',
        '@typescript-eslint/prefer-optional-chain': 'warn',
        '@typescript-eslint/prefer-ts-expect-error': 'warn',
        '@typescript-eslint/promise-function-async': 'error',
        '@typescript-eslint/func-call-spacing': ['error', 'never'],
        '@typescript-eslint/comma-spacing': 'warn',
        '@typescript-eslint/keyword-spacing': 'warn',
        '@typescript-eslint/consistent-indexed-object-style': ['error', 'record'],
        '@typescript-eslint/consistent-type-imports': ['error', { prefer: 'type-imports' }],
        '@typescript-eslint/member-delimiter-style': 'warn',
        '@typescript-eslint/type-annotation-spacing': 'warn',
        '@typescript-eslint/naming-convention': [
            'error',
            {
                "selector": "objectLiteralProperty",
                "format": ["camelCase"],
                "filter": {
                    "regex": "(^(UI)|(vue-(argument|modifier))|(doc-url))",
                    "match": false
                }
            }
        ],
        '@typescript-eslint/no-non-null-assertion': 'off',

        // https://eslint.vuejs.org/rules/
        // if unsure and eslint doesn't cover it please refer to https://v3.vuejs.org/style-guide/
        'vue/html-indent': ['warn', 4],
        'vue/component-name-in-template-casing': ['warn', 'PascalCase'],
        'vue/match-component-file-name': ['off', { // until we have storybook working
            extensions: ['jsx', 'vue', 'tsx']
        }],
        'vue/new-line-between-multi-line-property': 'warn',
        'vue/max-attributes-per-line': ['warn', {
            'singleline': 3,
            'multiline': 1
        }],
        "vue/first-attribute-linebreak": ["error", {
            "singleline": "beside",
            "multiline": "beside"
        }],
        'vue/no-boolean-default': ['error', 'default-false'],
        'vue/no-duplicate-attr-inheritance': 'error',
        'vue/no-empty-component-block': 'warn',
        'vue/no-multiple-objects-in-class': 'error',
        'vue/no-potential-component-option-typo': ['error', {
            presets: ['vue', 'vue-router']
        }],
        'vue/no-reserved-component-names': ['error', {
            'disallowVueBuiltInComponents': true,
            'disallowVue3BuiltInComponents': true
        }],
        'vue/no-template-target-blank': 'error',
        'vue/no-unsupported-features': ['error', {
            'version': '^3.0.0'
        }],
        'vue/no-useless-mustaches': 'warn',
        'vue/no-useless-v-bind': 'error',
        'vue/padding-line-between-blocks': 'warn',
        'vue/require-name-property': 'error',
        'vue/v-for-delimiter-style': 'error',
        'vue/v-on-event-hyphenation': 'error',
        'vue/v-on-function-call': ['error', 'never', {
            'ignoreIncludesComment': true
        }],
        'vue/eqeqeq': 'error',
        'vue/no-extra-parens': 'warn',
        'vue/html-closing-bracket-newline': ['warn', {
            'multiline': 'never'
        }],
        'vue/no-v-html': 'off',
        'vue/require-default-prop': 'off',
    },
    overrides: [
        {
            files: ["Demo.vue"],
            rules: {
                'vue/match-component-file-name': 'off'
            }
        },
        {
            files: [
                '*.test.ts'
            ],
            env: {
                jest: true,
                browser: true,
                es2020: true,
            },
            plugins: [
                "jest"
            ],
            extends: [
                "plugin:jest/all"
            ],
            parser: '@typescript-eslint/parser',
            rules: {
                "@typescript-eslint/no-empty-function": "off",
                "@typescript-eslint/no-unsafe-call": "off",
                "@typescript-eslint/no-unsafe-member-access": "off",

                // https://www.npmjs.com/package/eslint-plugin-jest#rules
                "jest/prefer-expect-assertions": "off",
                "jest/no-hooks": "off",
                "jest/prefer-called-with": "off",
                "jest/valid-title": ["error", {
                    mustMatch: {
                        it: '^should '
                    }
                }],
                "jest/no-restricted-matchers": [
                    "error",
                    {
                        "toBeFalsy": 'Use toBe(false) instead to avoid unexpected type coercion.',
                        "toBeTruthy": 'Use toBe(true) instead to avoid unexpected type coercion.',
                    }
                ],
                "jest/prefer-lowercase-title": [
                    "error",
                    {
                        "ignore": ["describe"]
                    }
                ],
                "jest/no-disabled-tests": "off",
                "jest/no-conditional-in-test": "off",
                "jest/prefer-snapshot-hint": "off",
                "jest/max-expects": "off"
            }
        }
    ]
}