fix: Allow overriding VariableModel via options.plugins. (#9257)

Author: gonfunko

core/registry.ts

@@ -119,9 +119,9 @@ export class Type<_T> {
   /** @internal */
   static PASTER = new Type<IPaster<ICopyData, ICopyable<ICopyData>>>('paster');
 
-  static VARIABLE_MODEL = new Type<IVariableModelStatic<IVariableState>>(
-    'variableModel',
-  );
+  static VARIABLE_MODEL = new Type<
+    IVariableModelStatic<IVariableState> & IVariableModel<IVariableState>
+  >('variableModel');
 
   static VARIABLE_MAP = new Type<IVariableMap<IVariableModel<IVariableState>>>(
     'variableMap',

core/variable_map.ts

@@ -255,9 +255,9 @@ export class VariableMap
     }
     const id = opt_id || idGenerator.genUid();
     const type = opt_type || '';
-    const VariableModel = registry.getObject(
+    const VariableModel = registry.getClassFromOptions(
       registry.Type.VARIABLE_MODEL,
-      registry.DEFAULT,
+      this.workspace.options,
       true,
     );
     if (!VariableModel) {