emberjs
diff --git a/‎packages/@ember/-internals/glimmer/tests/integration/custom-modifier-manager-test.js‎
Lines changed: 29 additions & 0 deletions b/‎packages/@ember/-internals/glimmer/tests/integration/custom-modifier-manager-test.js‎
Lines changed: 29 additions & 0 deletions
diff --git a/‎packages/@glimmer-workspace/integration-tests/test/modifiers/dynamic-modifiers-test.ts‎
Lines changed: 50 additions & 0 deletions b/‎packages/@glimmer-workspace/integration-tests/test/modifiers/dynamic-modifiers-test.ts‎
Lines changed: 50 additions & 0 deletions
@@ -105,6 +105,35 @@ class ModifierManagerTest extends RenderingTestCase {
     runTask(() => set(this.context, 'truthy', true));
   }
 
+  '@test destroys a dynamic modifier that was set after the initial render'(assert) {
+    let ModifierClass = setModifierManager(
+      (owner) => {
+        return new this.CustomModifierManager(owner);
+      },
+      class extends EmberObject {
+        didInsertElement() {
+          assert.step('didInsertElement');
+        }
+        didUpdate() {}
+        willDestroyElement() {
+          assert.step('willDestroyElement');
+        }
+      }
+    );
+
+    this.render('{{#if this.show}}<div {{this.dyn}}></div>{{/if}}', {
+      show: true,
+      dyn: undefined,
+    });
+    assert.verifySteps([]);
+
+    runTask(() => set(this.context, 'dyn', ModifierClass));
+    assert.verifySteps(['didInsertElement']);
+
+    runTask(() => set(this.context, 'show', false));
+    assert.verifySteps(['willDestroyElement']);
+  }
+
   '@test associates manager even through an inheritance structure'(assert) {
     assert.expect(5);
     let ModifierClass = setModifierManager(
 
@@ -7,6 +7,7 @@ import {
   RenderTest,
   syntaxErrorFor,
   test,
+  trackedObj,
 } from '@glimmer-workspace/integration-tests';
 
 class DynamicModifiersResolutionModeTest extends RenderTest {
@@ -199,6 +200,55 @@ class DynamicModifiersResolutionModeTest extends RenderTest {
     this.assertHTML('<div>Hello, world!</div>');
     this.assertStableRerender();
   }
+
+  @test
+  'Destroys a dynamic modifier that was set after the initial render when its block is removed'(
+    assert: Assert
+  ) {
+    const foo = defineSimpleModifier(() => {
+      assert.step('install');
+
+      return () => assert.step('destroy');
+    });
+
+    const Bar = defineComponent({}, '{{#if @show}}<div {{@foo}}></div>{{/if}}');
+    const args = trackedObj({ show: true, foo: undefined });
+
+    this.renderComponent(Bar, args);
+    assert.verifySteps([]);
+
+    args['foo'] = foo;
+    this.rerender();
+    assert.verifySteps(['install']);
+
+    args['show'] = false;
+    this.rerender();
+    assert.verifySteps(['destroy']);
+  }
+
+  @test
+  'Destroys a dynamic modifier that was set after the initial render when the render result is destroyed'(
+    assert: Assert
+  ) {
+    const foo = defineSimpleModifier(() => {
+      assert.step('install');
+
+      return () => assert.step('destroy');
+    });
+
+    const Bar = defineComponent({}, '<div {{@foo}}></div>');
+    const args = trackedObj({ foo: undefined });
+
+    this.renderComponent(Bar, args);
+    assert.verifySteps([]);
+
+    args['foo'] = foo;
+    this.rerender();
+    assert.verifySteps(['install']);
+
+    this.destroy();
+    assert.verifySteps(['destroy']);
+  }
 }
 
 jitSuite(DynamicModifiersResolutionModeTest);