handle driver.getObjectProperty results with no value property (#1892)

also handle errors thrown in driver.getObjectProperty
GoogleChrome · Mar 27, 2017 · e822cbe · e822cbe
1 parent 909a463
commit e822cbe
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/lighthouse-core/gather/driver.js b/lighthouse-core/gather/driver.js
@@ -496,7 +496,7 @@ class Driver {
   * @return {!Promise<string>} The property value, or null, if property not found
   */
   getObjectProperty(objectId, propName) {
-    return new Promise(resolve => {
+    return new Promise((resolve, reject) => {
       this.sendCommand('Runtime.getProperties', {
         objectId,
         accessorPropertiesOnly: true,
@@ -507,12 +507,12 @@ class Driver {
         const propertyForName = properties.result
           .find(property => property.name === propName);
 
-        if (propertyForName) {
+        if (propertyForName && propertyForName.value) {
           resolve(propertyForName.value.value);
         } else {
           resolve(null);
         }
-      });
+      }).catch(reject);
     });
   }
 

diff --git a/lighthouse-core/test/gather/driver-test.js b/lighthouse-core/test/gather/driver-test.js
@@ -74,6 +74,8 @@ connection.sendCommand = function(command, params) {
           value: {
             value: '123'
           }
+        }, {
+          name: 'novalue'
         }]
       });
     case 'Page.enable':
@@ -139,7 +141,13 @@ describe('Browser Driver', () => {
   });
 
   it('returns null when getObjectProperty finds no property name', () => {
-    return driverStub.getObjectProperty('invalid', 'invalid').catch(value => {
+    return driverStub.getObjectProperty('invalid', 'invalid').then(value => {
+      assert.deepEqual(value, null);
+    });
+  });
+
+  it('returns null when getObjectProperty finds property name with no value', () => {
+    return driverStub.getObjectProperty('test', 'novalue').then(value => {
       assert.deepEqual(value, null);
     });
   });