fix: improve eslint rule detecting (#457)

fixes #455

lib/utils.js

@@ -3,18 +3,19 @@
 const { getStaticValue, findVariable } = require('eslint-utils');
 const estraverse = require('estraverse');
 
+const functionTypes = new Set([
+  'FunctionExpression',
+  'ArrowFunctionExpression',
+  'FunctionDeclaration',
+]);
+
 /**
  * Determines whether a node is a 'normal' (i.e. non-async, non-generator) function expression.
  * @param {ASTNode} node The node in question
  * @returns {boolean} `true` if the node is a normal function expression
  */
 function isNormalFunctionExpression(node) {
-  const functionTypes = [
-    'FunctionExpression',
-    'ArrowFunctionExpression',
-    'FunctionDeclaration',
-  ];
-  return functionTypes.includes(node.type) && !node.generator && !node.async;
+  return functionTypes.has(node.type) && !node.generator && !node.async;
 }
 
 /**
@@ -150,12 +151,7 @@ function getRuleExportsESM(ast, scopeManager) {
           // skip if it's function-style to avoid false positives
           // refs: https://github.com/eslint-community/eslint-plugin-eslint-plugin/issues/450
           possibleNodes.push(
-            ...nodes.filter(
-              (node) =>
-                node &&
-                node.type !== 'FunctionDeclaration' &&
-                node.type !== 'FunctionExpression'
-            )
+            ...nodes.filter((node) => node && !functionTypes.has(node.type))
           );
         }
         break;

tests/lib/utils.js

@@ -91,6 +91,7 @@ describe('utils', () => {
         'export function foo(options) { return {}; }',
         'export async function foo(options) { return {}; }',
         'export const foo = function (options) { return {}; }',
+        'export const foo = (options) => { return {}; }',
         'export function foo(options) { return; }',
         'export function foo({opt1, opt2}) { return {}; }',