improve unit tests on get_instance

@@ -15,6 +15,7 @@ dependencies:
 
 dev_dependencies:
   test: ">=1.0.0 <2.0.0"
+  test_coverage: ">=0.4.3 <1.0.0"
 
 
 # For information on the generic Dart part of this file, see the

+// Auto-generated by test_coverage. Do not edit by hand.
+// Consider adding this file to your .gitignore.
+
+import 'get_instance_test.dart' as get_instance_test;
+
+void main() {
+  get_instance_test.main();
+}

@@ -13,6 +13,15 @@ class Mock {
 class Controller {}
 
 class DisposableController extends GetLifeCycle {
+  DisposableController() {
+    onStart.callback = _onStart;
+  }
+
+  // Internal callback that starts the cycle of this controller.
+  void _onStart() {
+    onInit();
+  }
+
   bool initialized = false;
 
   void onInit() async {

@@ -18,4 +18,5 @@ dependencies:
 
 dev_dependencies:
   test: ">=1.0.0 <2.0.0"
+  test_coverage: ">=0.4.3 <1.0.0"
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