fix(knex): The method getModel in the knex adapter (#3043)

Author: hugo-bach

packages/knex/src/adapter.ts

@@ -63,7 +63,7 @@ export class KnexAdapter<
     return this.getModel()
   }
 
-  getModel(params?: ServiceParams) {
+  getModel(params: ServiceParams = {} as ServiceParams) {
     const { Model } = this.getOptions(params)
     return Model
   }

packages/knex/test/overrides.test.ts

@@ -122,4 +122,11 @@ describe('Feathers Knex Overridden Method With Self-Join', () => {
 
     assert.strictEqual(patchedAnimal.name, newName)
   })
+
+  it('get the service model (getModel)', async () => {
+    const model = animalService.Model
+    const options = animalService.options
+
+    assert.strictEqual(model, options.Model)
+  })
 })