clean up helper functions

Author: Hweinstock

plugins/eslint-plugin-aws-toolkits/lib/rules/no-inline-async-foreach.ts

@@ -10,25 +10,38 @@ import { RuleContext } from '@typescript-eslint/utils/ts-eslint'
 
 export const errMsg = 'Avoid using async methods with .forEach as it leads to race conditions'
 
+function isFunctionExpression(
+    node: TSESTree.Node
+): node is TSESTree.ArrowFunctionExpression | TSESTree.FunctionExpression {
+    return node.type === AST_NODE_TYPES.ArrowFunctionExpression || node.type === AST_NODE_TYPES.FunctionExpression
+}
+
 function isAsyncFunction<T extends string, T2 extends readonly unknown[]>(
     context: RuleContext<T, T2>,
     funcNode: TSESTree.CallExpressionArgument
 ) {
     if (funcNode.type === AST_NODE_TYPES.Identifier) {
-        console.log('is identifier')
         const scope = context.sourceCode.getScope(funcNode)
         const maybeFNode =
             scope.variables.find((v) => v.name === funcNode.name)?.defs.find((d) => !!d)?.node ?? undefined
-        console.log(maybeFNode)
+        // function declartions Ex. async function f() {}
         if (
             maybeFNode &&
-            (maybeFNode.type === AST_NODE_TYPES.ArrowFunctionExpression ||
-                maybeFNode.type === AST_NODE_TYPES.FunctionExpression ||
-                maybeFNode.type === AST_NODE_TYPES.FunctionDeclaration) &&
+            (isFunctionExpression(maybeFNode) || maybeFNode.type === AST_NODE_TYPES.FunctionDeclaration) &&
             maybeFNode.async
         ) {
             return true
         }
+        // variable-style function declarations Ex. const f = async function () {}
+        if (
+            maybeFNode &&
+            maybeFNode.type === AST_NODE_TYPES.VariableDeclarator &&
+            maybeFNode.init &&
+            isFunctionExpression(maybeFNode.init) &&
+            maybeFNode.init.async
+        ) {
+            return true
+        }
         return false
     }
     return (

plugins/eslint-plugin-aws-toolkits/test/rules/no-inline-async-foreach.test.ts

@@ -25,6 +25,5 @@ getRuleTester().run('no-inline-async-foreach', rules['no-inline-async-foreach'],
         { code: 'async function f(){} \n list.forEach(f)', errors: [errMsg] },
         { code: 'const f = async () => {} \n list.forEach(f)', errors: [errMsg] },
         { code: 'const f = async function () {} \n list.forEach(f)', errors: [errMsg] },
-        { code: 'const f = function () {} \n list.forEach(f)', errors: [errMsg] },
     ],
 })