fix(prefer-await-to-then):member access without call (#362)

Author: ota-meshi

__tests__/prefer-await-to-then.js

@@ -21,6 +21,12 @@ ruleTester.run('prefer-await-to-then', rule, {
     }`,
     'something().then(async () => await somethingElse())',
     'function foo() { hey.somethingElse(x => {}) }',
+    `const isThenable = (obj) => {
+      return obj && typeof obj.then === 'function';
+    };`,
+    `function isThenable(obj) {
+      return obj && typeof obj.then === 'function';
+    }`,
   ],
 
   invalid: [

rules/prefer-await-to-then.js

@@ -35,7 +35,7 @@ module.exports = {
     }
 
     return {
-      MemberExpression(node) {
+      'CallExpression > MemberExpression.callee'(node) {
         if (isTopLevelScoped() || isInsideYieldOrAwait()) {
           return
         }