Class Compare<SourceType, TargetType>

omittedProperties

Properties that are present in the source object but not in the target object are considered "omitted" properties. As in they're properties that are present in the source object but omitted in the target object.

const obj1 = { prop1: 1,
               prop2: "foo" };

const obj2 = { prop1: 1 };

console.log(new Compare(obj1, obj2).omittedProperties);
// prints: { prop2: "foo" }

extraProperties

Properties that are not present in the source object but are present in the target object are considered "extra" properties. As in they're extra properties that are present in the target object but not in the source object.

const obj1 = { prop1: 1,
               prop2: "foo" };

const obj2 = { prop1: 1,
               prop2: "foo",
               prop3: true };

console.log(new Compare(obj1, obj2).extraProperties);
// prints: { prop3: true }

sharedProperties

Properties that are present in both the source and target object that are equivalent are considered "shared" properties. If there are keys that are present in both the source and target objects that are also mapped to equivalent values then the key-value pairs are considered shared properties.

const obj1 = { prop1: 1,
               prop2: "foo",
               prop3: false };

const obj2 = { prop1: 1,
               prop2: "foo",
               prop3: true };

console.log(new Compare(obj1, obj2).sharedProperties);
// prints: { prop1: 1,
//           prop2: "foo" }

alteredProperties

Properties that are present in both the source and target object that contain differing values are considered "altered" properties. If there are keys that are present in both the source and target objects that are mapped to differing values then the key-value pairs are considered altered properties.

const obj1 = { prop1: 1,
               prop2: "foo",
               prop3: false };

const obj2 = { prop1: 1,
               prop2: "foo",
               prop3: true };

console.log(new Compare(obj1, obj2).alteredProperties);
// prints: { prop3: { sourceValue: false,
//                    targetValue: true } }