docs: Add JS doc for Parse.Object.revert() (#555)

Author: NicksonYap

.husky/pre-commit

@@ -0,0 +1,4 @@
+#!/usr/bin/env sh
+. "$(dirname -- "$0")/_/husky.sh"
+
+npm run husky-pre-commit

_includes/js/queries.md

@@ -570,6 +570,34 @@ query.distinct("age")
   });
 ```
 
+## Local vs. Server Data
+
+The value of a Parse Object field is determined from two data sources: the last-known value sent by the server, and any local changes made via `.set()` that have not been saved and sent to the server yet. When calling `.get()` on a field, the returned value will be the unsaved local value, or if no change has been made, the last-known value sent by the server.
+
+If you called `.set()` on a field but did not save it, then calling `.get()` will always return the unsaved value, regardless of how the value changed on the server side.
+
+If this is not a desired behavior, use `.revert()` to clear and unsaved local changes applied to the object.
+
+```javascript
+// Save object
+const GameScore = Parse.Object.extend("GameScore");
+const localObject = new Parse.Object(GameScore);
+localObject.set('field', 'a');
+await localObject.save();
+
+// Modify object locally without saving it
+localObject.set('field', 'b');
+
+// Fetch local object from server
+const query = new Parse.Query(GameScore);
+const fetchedObject = await query.first();
+
+// Determine field value
+fetchedObject.get('field'); // Returns value 'b'
+fetchedObject.revert();
+fetchedObject.get('field'); // Returns value 'a'
+```
+
 ## Read Preference
 
 When using a MongoDB replica set, you can use the `query.readPreference(readPreference, includeReadPreference, subqueryReadPreference)` function to choose from which replica the objects will be retrieved. The `includeReadPreference` argument chooses from which replica the included pointers will be retrieved and the `subqueryReadPreference` argument chooses in which replica the subqueries will run. The possible values are `PRIMARY` (default), `PRIMARY_PREFERRED`, `SECONDARY`, `SECONDARY_PREFERRED`, or `NEAREST`. If the `includeReadPreference` argument is not passed, the same replica chosen for `readPreference` will be also used for the includes. The same rule applies for the `subqueryReadPreference` argument.

assets/js/bundle.js

@@ -11,7 +11,7 @@
     "dev": "npm run dev-webpack & npm run jekyll",
     "dev-win": "start npm run dev-webpack & start npm run jekyll",
     "prod": "npm run webpack & npm run jekyll",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "husky-pre-commit": "npm run webpack && git add assets/js/bundle.js"
   },
   "repository": {
     "type": "git",
@@ -29,17 +29,12 @@
     "babel-loader": "8.3.0",
     "babel-preset-es2015": "6.24.1",
     "babel-preset-react": "6.24.1",
-    "husky": "8.0.3",
+    "husky": "9.0.11",
     "webpack": "5.76.0",
     "webpack-cli": "4.1.0"
   },
   "dependencies": {
     "jquery": "3.5.1",
     "underscore": "1.12.1"
-  },
-  "husky": {
-    "hooks": {
-      "pre-commit": "npm run webpack && git add assets/js/bundle.js"
-    }
   }
 }