chore: add new eslint setup

eslint.config.mjs

@@ -0,0 +1,103 @@
+/* eslint-disable import/no-unresolved -- We don't care about resolving imports in here  */
+
+import eslint from '@eslint/js';
+import eslintCommentPlugin from '@eslint-community/eslint-plugin-eslint-comments/configs';
+import stylisticPlugin from '@stylistic/eslint-plugin';
+import importPlugin from 'eslint-plugin-import';
+import tseslint from 'typescript-eslint';
+
+const stylisticConfig = stylisticPlugin.configs.customize({
+	indent: 'tab',
+	quotes: 'single',
+	semi: true,
+	commaDangle: 'never',
+	braceStyle: '1tbs'
+});
+
+export default tseslint.config(
+	{
+		// https://eslint.org/docs/rules/
+		extends: [eslint.configs.recommended],
+		rules: {
+			'require-atomic-updates': 'off', // This rule is widely controversial and causes false positives
+			'no-console': 'off',
+			'prefer-const': 'error',
+			'no-var': 'error',
+			'no-unused-vars': [
+				'error',
+				{ argsIgnorePattern: '^_', caughtErrorsIgnorePattern: '^ignore' }
+			],
+			'one-var': ['error', 'never']
+		}
+	},
+	{
+		// https://typescript-eslint.io/rules/
+		extends: [tseslint.configs.recommended],
+		files: ['**/*.ts', '**/*.d.ts'],
+		rules: {
+			'@typescript-eslint/no-unused-vars': [
+				'error',
+				{ argsIgnorePattern: '^_', caughtErrorsIgnorePattern: '^ignore' }
+			],
+			'@typescript-eslint/no-inferrable-types': 'off',
+			'@typescript-eslint/explicit-function-return-type': 'error',
+			'@typescript-eslint/no-explicit-any': 'off',
+			'@typescript-eslint/no-empty-object-type': ['off'],
+			'@typescript-eslint/no-import-type-side-effects': 'error',
+			'@typescript-eslint/consistent-type-imports': ['error', {
+				fixStyle: 'separate-type-imports'
+			}]
+		}
+	},
+	{
+		// https://eslint-community.github.io/eslint-plugin-eslint-comments/rules/
+		extends: [eslintCommentPlugin.recommended],
+		rules: {
+			'@eslint-community/eslint-comments/disable-enable-pair': ['error', { allowWholeFile: true }],
+			'@eslint-community/eslint-comments/require-description': 'error'
+		}
+	},
+	{
+		// https://eslint.style/rules
+		extends: [stylisticConfig],
+		rules: {
+			'@stylistic/no-extra-semi': 'error',
+			'@stylistic/yield-star-spacing': ['error', 'after'],
+			'@stylistic/operator-linebreak': ['error', 'after', { overrides: { '?': 'before', ':': 'before' } }],
+			'@stylistic/curly-newline': ['error', {
+				multiline: true,
+				consistent: true
+			}],
+			'@stylistic/object-curly-newline': ['error', {
+				multiline: true,
+				consistent: true
+			}]
+		}
+	},
+	{
+		// https://www.npmjs.com/package/eslint-plugin-import
+		extends: [importPlugin.flatConfigs.recommended, importPlugin.flatConfigs.warnings],
+		rules: {
+			'import/order': ['warn', {
+				'groups': ['builtin', 'external', 'internal', 'parent', 'sibling', 'index', 'object', 'type'],
+				'newlines-between': 'never'
+			}],
+			'import/first': 'error',
+			'import/consistent-type-specifier-style': ['error', 'prefer-top-level']
+		}
+	},
+	{
+		// https://www.npmjs.com/package/eslint-plugin-import - but specifically for TypeScript
+		extends: [importPlugin.flatConfigs.typescript],
+		files: ['**/*.ts', '**/*.d.ts'],
+		settings: {
+			'import/resolver': {
+				typescript: {
+					alwaysTryTypes: true,
+					project: './tsconfig.json'
+				},
+				node: true
+			}
+		}
+	}
+);