[BUGFIX release] Include renderComponent roots in captureRenderTree

packages/@ember/-internals/glimmer/lib/base-renderer.ts

@@ -1,6 +1,7 @@
 import { ENV } from '@ember/-internals/environment/lib/env';
 import type { InternalOwner } from '@ember/-internals/owner';
 import { assert } from '@ember/debug';
+import { registerComponentRenderer } from '@ember/debug/lib/capture-render-tree';
 import { _backburner, _getCurrentRunLoop } from '@ember/runloop';
 import {
   associateDestroyableChild,
@@ -516,6 +517,7 @@ export function renderComponent(
       hasDOM: env && 'hasDOM' in env ? Boolean(env?.['hasDOM']) : true,
     });
     RENDERER_CACHE.set(owner, renderer);
+    registerComponentRenderer(owner, renderer);
   }
 
   /**

packages/@ember/-internals/glimmer/tests/integration/application/debug-render-tree-test.ts

@@ -1,7 +1,7 @@
 import { ApplicationTestCase, ModuleBasedTestResolver, moduleFor } from 'internal-test-helpers';
 
 import { ENV } from '@ember/-internals/environment';
-import { Component, setComponentManager } from '@ember/-internals/glimmer';
+import { Component, renderComponent, setComponentManager } from '@ember/-internals/glimmer';
 import type { InternalOwner } from '@ember/-internals/owner';
 import Route from '@ember/routing/route';
 import Controller from '@ember/controller';
@@ -1127,6 +1127,53 @@ if (ENV._DEBUG_RENDER_TREE) {
         ]);
       }
 
+      async '@test components rendered with renderComponent'() {
+        await this.visit('/');
+
+        let HelloWorld = setComponentTemplate(
+          precompileTemplate('Hello {{@name}}', { strictMode: true }),
+          templateOnly()
+        );
+        let Root = setComponentTemplate(
+          precompileTemplate('<HelloWorld @name="world" />', {
+            strictMode: true,
+            scope: () => ({ HelloWorld }),
+          }),
+          templateOnly()
+        );
+        let into = document.createElement('div');
+
+        let result = runTask(() => renderComponent(Root, { owner: this.owner, into }));
+
+        let roots = captureRenderTree(this.owner).filter((node) => node.type === 'component');
+
+        this.assertRenderNodes(
+          roots,
+          [
+            {
+              type: 'component',
+              name: '{ROOT}',
+              args: { positional: [], named: {} },
+              instance: null,
+              bounds: this.elementBounds(into),
+              children: [
+                {
+                  type: 'component',
+                  name: 'HelloWorld',
+                  args: { positional: [], named: { name: 'world' } },
+                  instance: null,
+                  bounds: this.elementBounds(into),
+                  children: [],
+                },
+              ],
+            },
+          ],
+          'root'
+        );
+
+        runTask(() => result.destroy());
+      }
+
       async '@test <Input> components'() {
         this.add(
           'template:application',

packages/@ember/debug/lib/capture-render-tree.ts

@@ -1,7 +1,21 @@
 import type { Renderer } from '@ember/-internals/glimmer/lib/renderer';
+import type { BaseRenderer } from '@ember/-internals/glimmer/lib/base-renderer';
 import type Owner from '@ember/owner';
 import type { CapturedRenderNode } from '@glimmer/interfaces';
 
+/**
+ * `renderComponent` renders with its own renderer per owner,
+ * separate from the owner's `renderer:-dom`.
+ *
+ * The renderer registers itself here,
+ * because importing it would be a circular import.
+ */
+const COMPONENT_RENDERERS = new WeakMap<object, BaseRenderer>();
+
+export function registerComponentRenderer(owner: object, renderer: BaseRenderer): void {
+  COMPONENT_RENDERERS.set(owner, renderer);
+}
+
 /**
   @module @ember/debug
 */
@@ -19,14 +33,22 @@ import type { CapturedRenderNode } from '@glimmer/interfaces';
   @since 3.14.0
 */
 export default function captureRenderTree(app: Owner): CapturedRenderNode[] {
-  let domRenderer = app.lookup('renderer:-dom') as Renderer;
+  let domRenderer = app.lookup('renderer:-dom') as Renderer | undefined;
+  let componentRenderer = COMPONENT_RENDERERS.get(app);
 
-  if (!domRenderer) {
+  if (!domRenderer && !componentRenderer) {
     throw new Error(`BUG: owner is missing renderer`);
   }
   // SAFETY: Ideally we'd assert here but that causes awkward circular requires since this is also in @ember/debug.
   // This is only for debug stuff so not very risky.
-  let renderer = domRenderer;
 
-  return renderer.debugRenderTree.capture();
+  let nodes: CapturedRenderNode[] = domRenderer ? domRenderer.debugRenderTree.capture() : [];
+
+  if (componentRenderer) {
+    for (let node of componentRenderer.debugRenderTree.capture()) {
+      nodes.push(node);
+    }
+  }
+
+  return nodes;
 }