Upgrade eslint

eslint.config.mjs

@@ -0,0 +1,98 @@
+// @ts-check
+
+import {fixupPluginRules} from '@eslint/compat'
+import {FlatCompat} from '@eslint/eslintrc'
+import jsEslint from '@eslint/js'
+import eslintConfigPrettier from 'eslint-config-prettier'
+import tsEslint from 'typescript-eslint'
+
+const compat = new FlatCompat({
+  baseDirectory: import.meta.dirname,
+  recommendedConfig: jsEslint.configs.recommended,
+  allConfig: jsEslint.configs.all
+})
+
+/* eslint-disable @typescript-eslint/explicit-function-return-type */
+/**
+ * @param {string} name the pugin name
+ * @param {string} alias the plugin alias
+ * @returns {import("eslint").ESLint.Plugin}
+ */
+function legacyPlugin(name, alias = name) {
+  const plugin = compat.plugins(name)[0]?.plugins?.[alias]
+
+  if (!plugin) {
+    throw new Error(`Unable to resolve plugin ${name} and/or alias ${alias}`)
+  }
+
+  return fixupPluginRules(plugin)
+}
+/* eslint-enable @typescript-eslint/explicit-function-return-type */
+
+export default tsEslint.config(
+  jsEslint.configs.recommended,
+  ...tsEslint.configs.strictTypeChecked,
+  ...tsEslint.configs.stylisticTypeChecked,
+  {
+    languageOptions: {
+      parserOptions: {
+        projectService: {
+          allowDefaultProject: ['*.js', '*.mjs']
+        },
+        tsconfigRootDir: import.meta.dirname
+      }
+    }
+  },
+  {
+    ignores: ['coverage', 'dist', 'lib']
+  },
+  {
+    plugins: {
+      github: legacyPlugin('eslint-plugin-github', 'github'), // pending https://github.com/github/eslint-plugin-github/issues/513
+      import: legacyPlugin('eslint-plugin-import', 'import') // Needed for above
+    },
+    rules: {
+      '@typescript-eslint/await-thenable': 'warn',
+      '@typescript-eslint/explicit-function-return-type': 'warn',
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-floating-promises': ['warn', {ignoreIIFE: true, ignoreVoid: false}],
+      '@typescript-eslint/no-shadow': 'error',
+      '@typescript-eslint/no-unused-vars': ['warn', {argsIgnorePattern: '^_'}],
+      '@typescript-eslint/restrict-template-expressions': [
+        'error',
+        {
+          allowNever: true,
+          allowNumber: true
+        }
+      ],
+      'github/array-foreach': 'error',
+      'github/no-implicit-buggy-globals': 'error',
+      'github/no-then': 'error',
+      'github/no-dynamic-script-tag': 'error',
+      'import/no-extraneous-dependencies': [
+        'error',
+        {
+          devDependencies: true,
+          optionalDependencies: true,
+          peerDependencies: true
+        }
+      ],
+      'import/order': ['warn', {'newlines-between': 'always', alphabetize: {order: 'asc'}}],
+      'no-console': ['warn']
+    }
+  },
+  {
+    files: ['**/*.test.ts'],
+    rules: {
+      '@typescript-eslint/explicit-function-return-type': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+      '@typescript-eslint/no-unsafe-assignment': 'off',
+      '@typescript-eslint/no-unsafe-member-access': 'off'
+    }
+  },
+  {
+    files: ['**/*.js', '**/*.mjs'],
+    ...tsEslint.configs.disableTypeChecked
+  },
+  eslintConfigPrettier
+)