Remove $register and call $sync manually

Require users to call the initial sync function themselves.
Remove the $register function, and move the method registrations into
the Model constructor.

Update the docs

README.md

@@ -192,6 +192,9 @@ const model = await modelsClient.models.get<Post>({
   $merge: merge,
 })
 
+// run the initial sync
+await model.$sync()
+
 // subscribe to live changes to the model data!
 model.subscribe((err, post) => {
   if (err) {

docs/concepts/usage.md

@@ -29,15 +29,16 @@ Note that we pass in the shape of our data model (`Post`) as a type parameter.
 In order to instantiate the model, we need to pass some *registrations* which link up the model to your application code.
 
 ```ts
-await modelsClient.models.get<Post>({
+const model = await modelsClient.models.get<Post>({
   name: /* ... */,
   channelName: /* ... */,
   $sync: /* ... */,
   $merge: /* ... */,
 })
-```
 
-Let's take a look at each of these registrations in turn.
+// run the initial sync
+await model.$sync()
+```
 
 ## Sync Function
 
@@ -57,10 +58,12 @@ async function sync() {
   return result.json();
 }
 
-await modelsClient.models.get<Post>({
+const model = await modelsClient.models.get<Post>({
   $sync: /* ... */,
   /* other registrations */
 })
+
+await model.$sync()
 ```
 
 The model will invoke this function at the start of its lifecycle to initialise your model state. Additionally, this function will be invoked if the model needs to re-synchronise at any point, for example after an extended period of network disconnectivity.

src/Model.discontinuity.test.ts

@@ -47,11 +47,12 @@ describe('Model', () => {
     let counter = 0;
 
     const sync = vi.fn(async () => `${counter++}`);
-    const model = new Model<string>('test', { ably, channelName, logger });
     const mergeFn = vi.fn(async (_, event) => {
       return event.data;
     });
-    await model.$register({ $sync: sync, $merge: mergeFn });
+
+    const model = new Model<string>('test', { $sync: sync, $merge: mergeFn }, { ably, channelName, logger });
+    await model.$sync();
 
     expect(sync).toHaveBeenCalledOnce();