fix: requireReturnsCheck false positve on async functions (fixes #174)

Author: chiawendt

README.md

@@ -2302,6 +2302,16 @@ function quux () {
  * @returns {*} Foo.
  */
 const quux = () => foo;
+
+/** 
+ * @returns {Promise<void>}
+ */
+async function quux() {}
+
+/** 
+ * @returns {Promise<void>}
+ */
+async () => {}
 ````
 
 

src/rules/requireReturnsCheck.js

@@ -24,6 +24,11 @@ export default iterateJsdoc(({
     return;
   }
 
+  // Async function always returns a promise
+  if (functionNode.async) {
+    return;
+  }
+
   if (JSON.stringify(jsdocTags) !== '[]' && voidReturn && sourcecode.indexOf('return') < 1) {
     report('Present JSDoc @' + targetTagName + ' declaration but not available return expression in function.');
   }

test/rules/assertions/requireReturnsCheck.js

@@ -104,6 +104,28 @@ export default {
            */
           const quux = () => foo;
       `
+    },
+    {
+      code: `
+          /** 
+           * @returns {Promise<void>}
+           */
+          async function quux() {}
+      `,
+      parserOptions: {
+        ecmaVersion: 8
+      }
+    },
+    {
+      code: `
+          /** 
+           * @returns {Promise<void>}
+           */
+          async () => {}
+      `,
+      parserOptions: {
+        ecmaVersion: 8
+      }
     }
   ]
 };