Match types for User#callFunction implementation across platforms

The unifies the call signature of User#callFunction across all documentation
and platforms.
`callFunction` now has the signature:
```javascript
  user.callFunction('func', 1, 2, 3);
```

CHANGELOG.md

@@ -1,5 +1,12 @@
 x.x.x Release notes (yyyy-MM-dd)
 =============================================================
+### Breaking change
+* Unify the call signature documentation of `User#callFunction` ([#3733](https://github.com/realm/realm-js/issues/3733))
+    * Example:
+    ```javascript
+    user.callFunction("sum", 1, 2, 3); // Valid
+    user.callFunction("sum", [1, 2, 3]); // Invalid
+    ```
 ### Enhancements
 * None.
 

docs/sync.js

@@ -871,10 +871,10 @@ class User {
   /**
    * Calls the named server function as this user.
    * @param {string} name - name of the function to call
-   * @param {any[]} args = [] - list of arguments to pass
+   * @param {...*} [args] - arguments to pass to the function
    * @return {Promise<any>} - resolves when the function terminates.
    */
-  callFunction(name, args) {}
+  callFunction(name, ...args) {}
 
   /**
    * Convenience wrapper around `callFunction(name, [args])`

lib/user.js

@@ -30,10 +30,14 @@ const instanceMethods = {
     return promisify((cb) => this._logOut(cb));
   },
 
-  async callFunction(name, args = [], service = undefined) {
+  async callFunction(name, ...args) {
+    this._callFunctionOnService(name, undefined, ...args);
+  },
+
+  async _callFunctionOnService(name, serviceName, ...args) {
     const cleanedArgs = cleanArguments(args);
     const stringifiedArgs = EJSON.stringify(cleanedArgs, { relaxed: false });
-    const result = await promisify((cb) => this._callFunction(name, stringifiedArgs, service, cb));
+    const result = await promisify((cb) => this._callFunction(name, stringifiedArgs, serviceName, cb));
     return EJSON.parse(result);
   },
 
@@ -98,15 +102,15 @@ const instanceMethods = {
   },
 
   // Internal helpers.
-  _functionsOnService(service) {
+  _functionsOnService(serviceName) {
     const user = this;
     return new Proxy(
       {},
       {
         get(target, name, receiver) {
           if (typeof name === "string" && name != "inspect") {
             return (...args) => {
-              return user.callFunction(name, args, service);
+              return user._callFunctionOnService(name, serviceName, args);
             };
           } else {
             return Reflect.get(target, name, receiver);

tests/js/user-tests.js

@@ -333,7 +333,7 @@ module.exports = {
     let user = await app.logIn(credentials);
 
     TestCase.assertEqual(await user.callFunction("sumFunc"), 0);
-    TestCase.assertEqual(await user.callFunction("sumFunc", [123]), 123);
+    TestCase.assertEqual(await user.callFunction("sumFunc", 123), 123);
     TestCase.assertEqual(await user.functions.sumFunc(123), 123);
     TestCase.assertEqual(await user.functions["sumFunc"](123), 123);
 

types/app.d.ts

@@ -404,7 +404,7 @@ declare namespace Realm {
   class User<
     FunctionsFactoryType = DefaultFunctionsFactory,
     CustomDataType = SimpleObject,
-    UserProfileDataType = DefaultUserProfileData,
+    UserProfileDataType = DefaultUserProfileData
   > {
     /**
      * The automatically-generated internal ID of the user.
@@ -490,7 +490,7 @@ declare namespace Realm {
      *
      * @example
      * // These are all equivalent:
-     * await user.callFunction("doThing", [a1, a2, a3]);
+     * await user.callFunction("doThing", a1, a2, a3);
      * await user.functions.doThing(a1, a2, a3);
      * await user.functions["doThing"](a1, a2, a3);
      * @example