fix(check-types): proper use of optional chaining; fixes #861

Author: brettz9

README.md

@@ -5576,6 +5576,18 @@ function quux (foo) {
 }
 // Settings: {"jsdoc":{"mode":"typescript"}}
 // Message: Invalid JSDoc @param "foo" type "object"; prefer: "Object<>".
+
+/**
+ *
+ * @param {Object} param
+ * @return {Object | String}
+ */
+function abc(param) {
+  if (param.a)
+    return {};
+  return 'abc';
+}
+// Message: Invalid JSDoc @param "param" type "Object"; prefer: "object".
 ````
 
 The following patterns are not considered problems:

src/rules/checkTypes.js

@@ -206,8 +206,8 @@ export default iterateJsdoc(({
           //   `unifyParentAndChildTypeChecks`) and we don't want
           //   `object<>` given TypeScript issue https://github.com/microsoft/TypeScript/issues/20555
           parentNode?.elements.length && (
-            parentNode?.left.type === 'JsdocTypeName' &&
-            parentNode?.left.value === 'Object'
+            parentNode?.left?.type === 'JsdocTypeName' &&
+            parentNode?.left?.value === 'Object'
           )
         )
       ) {

test/rules/assertions/checkTypes.js

@@ -2356,6 +2356,46 @@ export default {
         },
       },
     },
+    {
+      code: `
+        /**
+         *
+         * @param {Object} param
+         * @return {Object | String}
+         */
+        function abc(param) {
+          if (param.a)
+            return {};
+          return 'abc';
+        }
+      `,
+      errors: [
+        {
+          line: 4,
+          message: 'Invalid JSDoc @param "param" type "Object"; prefer: "object".',
+        },
+        {
+          line: 5,
+          message: 'Invalid JSDoc @return type "Object"; prefer: "object".',
+        },
+        {
+          line: 5,
+          message: 'Invalid JSDoc @return type "String"; prefer: "string".',
+        },
+      ],
+      output: `
+        /**
+         *
+         * @param {object} param
+         * @return {Object | String}
+         */
+        function abc(param) {
+          if (param.a)
+            return {};
+          return 'abc';
+        }
+      `,
+    },
   ],
   valid: [
     {