chore: update eslint, fix lint issues

Author: macno

.eslintrc.js

@@ -0,0 +1,7 @@
+{
+  "singleQuote": true,
+  "arrowParens": "avoid",
+  "printWidth": 120,
+  "bracketSpacing": true,
+  "trailingComma": "none"
+}

.prettierrc

@@ -0,0 +1,85 @@
+import globals from 'globals';
+import pluginJs from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import pluginPrettierRecommended from 'eslint-plugin-prettier/recommended';
+import nodePlugin from 'eslint-plugin-n';
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  {
+    name: 'ignore files',
+    ignores: ['dist/', 'build/', 'reports/', 'node_modules/']
+  },
+  {
+    name: 'include files',
+    files: ['**/*.{js,mjs,cjs,ts}']
+  },
+  {
+    name: 'globals for node',
+    files: ['**/*.{mjs,cjs,ts}'],
+    languageOptions: { globals: globals.node }
+  },
+  {
+    ...pluginJs.configs.recommended,
+    name: 'plugin-js recommended'
+  },
+  {
+    ...nodePlugin.configs['flat/recommended-module'],
+    name: 'custom eslint-plugin-n plugin config',
+    files: ['**/*.ts'],
+    rules: {
+      'n/no-process-env': 'error',
+      'n/no-missing-import': [
+        'off', // eslint-plugin-n fails to resolve index.ts files
+        {
+          tryExtensions: ['.ts', '.d.ts']
+        }
+      ]
+    },
+    languageOptions: {
+      globals: {
+        ...globals.node,
+        NodeJS: true
+      }
+    }
+  },
+  {
+    ...nodePlugin.configs['flat/recommended-module'],
+    name: 'custom eslint-plugin-n plugin config for tests',
+    files: ['tests*/**/*.ts'],
+    // eslint-plugin-n rules
+    rules: {
+      'n/no-process-env': 'off'
+    },
+    languageOptions: {
+      globals: {
+        ...globals.jest
+      }
+    }
+  },
+  ...tseslint.configs.recommended.map(config => ({
+    ...config,
+    files: ['**/*.ts'],
+    rules: {
+      'no-unused-vars': 'off',
+      'no-redeclare': 'off',
+      '@typescript-eslint/no-redeclare': 'error',
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        {
+          argsIgnorePattern: '^_',
+          caughtErrorsIgnorePattern: '^_'
+        }
+      ]
+    }
+  })),
+  {
+    // eslint core rules
+    rules: {
+      complexity: ['error', 10],
+      'no-console': 'error',
+      eqeqeq: ['error', 'smart']
+    }
+  },
+  pluginPrettierRecommended
+];