Did I reproduce a different issue?

Author: NullVoxPopuli

packages/@glimmer-workspace/integration-tests/lib/suites/components.ts

@@ -866,7 +866,7 @@ export class GlimmerishComponents extends RenderTest {
   @test({ kind: 'glimmer' }) 'destruction is not autotracked'() {
     class State {
       @tracked willDestroyCalls = 0;
-      increment = () => this.willDestroyCalls++;
+      incrementWillDestroy = () => this.willDestroyCalls++;
     }
     let state = new State();
     class Child extends GlimmerishComponent {
@@ -884,26 +884,62 @@ export class GlimmerishComponents extends RenderTest {
     this.registerComponent(
       'Glimmer',
       'Example',
-      `
-      <p>willDestroyCalls: {{@willDestroyCalls}}</p>
+      `<p>willDestroyCalls: {{@willDestroyCalls}}</p>
       <button {{on "click" this.toggleChild}}>Toggle child</button>
 
       {{#if this.showChild}}
         <Child @incrementWillDestroy={{@incrementWillDestroy}} />
-      {{/if}}
-      `,
+      {{/if}}`,
       Example
     );
 
     this.render(
-      '<Example @incrementWillDestroy={{this.state.increment}} @willDestroyCalls={{this.state.willDestroyCalls}} />',
+      `<Example
+         @incrementWillDestroy={{this.state.incrementWillDestroy}}
+         @willDestroyCalls={{this.state.willDestroyCalls}}
+       />`,
       { state }
     );
 
-    this.assert.strictEqual(this.takeSnapshot(), '..');
-    this.assert.strictEqual(state.willDestroyCalls, 0);
-    this.assertHTML('', 'p', 'destroys correctly');
+    // Helper because assertHTML is invisible-character sensitive, and this test doesn't care about
+    // that.
+    // Where is qunit-dom?
+    let output = (calls: number, hasChild: boolean) => {
+      if (hasChild) {
+        return `<p>willDestroyCalls: ${calls}</p>
+      <button>Toggle child</button>
 
+        a child
+`;
+      }
+      return `<p>willDestroyCalls: ${calls}</p>
+      <button>Toggle child</button>
+<!---->
+`;
+    };
+
+    const el = () => this.element as unknown as HTMLElement;
+    const click = () => {
+      el().querySelector('button')?.click();
+      this.rerender();
+    };
+
+    this.assert.strictEqual(state.willDestroyCalls, 0, '0 destructions');
+    this.assertHTML(output(0, true), 'initial render');
+
+    click();
+    this.assert.strictEqual(state.willDestroyCalls, 1, '1 destruction');
+    this.assertHTML(output(1, false), 'destroyed once');
+
+    click();
+    this.assert.strictEqual(state.willDestroyCalls, 1, '1 destruction');
+    this.assertHTML(output(1, true), 'shown again, no change');
+
+    click();
+    this.assert.strictEqual(state.willDestroyCalls, 2, '2 destruction');
+    this.assertHTML(output(2, false), 'destroyed twice');
+
+    this.destroy();
     this.assertHTML('', 'destroys correctly');
   }