Fixed an issue with not being able to call createMachine in a gener…

…ic context (#3027)

* Remove type assertion in createMachine

* Add a type test for a generic context

* Update .changeset/lemon-mugs-attack.md

Co-authored-by: Daniel Playfair Cal <dcal@atlassian.com>
Co-authored-by: Mateusz Burzyński <mateuszburzynski@gmail.com>

.changeset/lemon-mugs-attack.md

@@ -0,0 +1,5 @@
+---
+'xstate': patch
+---
+
+Fixed an issue with not being able to call `createMachine` in a generic context when the type for the context was generic and not concrete.

packages/core/src/Machine.ts

@@ -1,4 +1,3 @@
-import { Model } from './model.types';
 import { StateNode } from './StateNode';
 import {
   AnyEventObject,
@@ -86,16 +85,14 @@ export function createMachine<
   TServiceMap extends ServiceMap = ServiceMap,
   TTypesMeta extends TypegenConstraint = TypegenDisabled
 >(
-  config: TContext extends Model<any, any, any, any>
-    ? 'Model type no longer supported as generic type. Please use `model.createMachine(...)` instead.'
-    : MachineConfig<
-        TContext,
-        any,
-        TEvent,
-        BaseActionObject,
-        TServiceMap,
-        TTypesMeta
-      >,
+  config: MachineConfig<
+    TContext,
+    any,
+    TEvent,
+    BaseActionObject,
+    TServiceMap,
+    TTypesMeta
+  >,
   options?: InternalMachineOptions<
     TContext,
     TEvent,

packages/core/test/types.test.ts

@@ -1,5 +1,12 @@
 import { from } from 'rxjs';
-import { Machine, assign, createMachine, interpret } from '../src/index';
+import {
+  Machine,
+  assign,
+  createMachine,
+  interpret,
+  StateMachine,
+  MachineConfig
+} from '../src/index';
 import { raise } from '../src/actions';
 
 function noop(_x: unknown) {
@@ -410,6 +417,16 @@ describe('context', () => {
       }
     );
   });
+
+  it('should work with generic context', () => {
+    function createMachineWithExtras<TContext>(
+      context: TContext
+    ): StateMachine<TContext, any, any> {
+      return createMachine({ context });
+    }
+
+    createMachineWithExtras({ counter: 42 });
+  });
 });
 
 describe('interpreter', () => {