diff --git a/src/core/singletons/tests/components-registry.test.ts b/src/core/singletons/tests/components-registry.test.ts
new file mode 100644
index 000000000..4cdeb231a
--- /dev/null
+++ b/src/core/singletons/tests/components-registry.test.ts
@@ -0,0 +1,104 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { wait } from '@/testing/utils';
+import { CoreComponentsRegistry } from '@singletons/components-registry';
+
+const cssClassName = 'core-components-registry-test';
+const createAndRegisterInstance = () => {
+    const element = document.createElement('div');
+    element.classList.add(cssClassName);
+    const instance = new ComponentsRegistryTestClass();
+
+    CoreComponentsRegistry.register(element, instance);
+
+    return { element, instance };
+};
+
+describe('CoreComponentsRegistry singleton', () => {
+
+    let element: HTMLElement;
+    let testClassInstance: ComponentsRegistryTestClass;
+
+    beforeEach(() => {
+        const result = createAndRegisterInstance();
+        element = result.element;
+        testClassInstance = result.instance;
+    });
+
+    it('resolves stored instances', () => {
+        expect(CoreComponentsRegistry.resolve(element)).toEqual(testClassInstance);
+        expect(CoreComponentsRegistry.resolve(element, ComponentsRegistryTestClass)).toEqual(testClassInstance);
+        expect(CoreComponentsRegistry.resolve(element, CoreComponentsRegistry)).toEqual(null);
+        expect(CoreComponentsRegistry.resolve(document.createElement('div'))).toEqual(null);
+    });
+
+    it('requires stored instances', () => {
+        expect(CoreComponentsRegistry.require(element)).toEqual(testClassInstance);
+        expect(CoreComponentsRegistry.require(element, ComponentsRegistryTestClass)).toEqual(testClassInstance);
+        expect(() => CoreComponentsRegistry.require(element, CoreComponentsRegistry)).toThrow();
+        expect(() => CoreComponentsRegistry.require(document.createElement('div'))).toThrow();
+    });
+
+    it('waits for component ready', async () => {
+        expect(testClassInstance.isReady).toBe(false);
+
+        await CoreComponentsRegistry.waitComponentReady(element);
+
+        expect(testClassInstance.isReady).toBe(true);
+    });
+
+    it('waits for components ready: just one', async () => {
+        expect(testClassInstance.isReady).toBe(false);
+
+        await CoreComponentsRegistry.waitComponentsReady(element, `.${cssClassName}`);
+
+        expect(testClassInstance.isReady).toBe(true);
+    });
+
+    it('waits for components ready: multiple', async () => {
+        const secondResult = createAndRegisterInstance();
+        const thirdResult = createAndRegisterInstance();
+        thirdResult.element.classList.remove(cssClassName); // Remove the class so the element and instance aren't treated.
+
+        const parent = document.createElement('div');
+        parent.appendChild(element);
+        parent.appendChild(secondResult.element);
+        parent.appendChild(thirdResult.element);
+
+        expect(testClassInstance.isReady).toBe(false);
+        expect(secondResult.instance.isReady).toBe(false);
+        expect(thirdResult.instance.isReady).toBe(false);
+
+        await CoreComponentsRegistry.waitComponentsReady(parent, `.${cssClassName}`);
+
+        expect(testClassInstance.isReady).toBe(true);
+        expect(secondResult.instance.isReady).toBe(true);
+        expect(thirdResult.instance.isReady).toBe(false);
+    });
+
+});
+
+class ComponentsRegistryTestClass {
+
+    randomId = Math.random();
+    isReady = false;
+
+    async ready(): Promise<void> {
+        await wait(50);
+
+        this.isReady = true;
+    }
+
+}
diff --git a/src/testing/utils.ts b/src/testing/utils.ts
index cd9a09696..4f097a35a 100644
--- a/src/testing/utils.ts
+++ b/src/testing/utils.ts
@@ -256,3 +256,16 @@ export async function renderWrapperComponent<T>(
 export function agnosticPath(unixPath: string): string {
     return unixPath.replace(/\//g, sep);
 }
+
+/**
+ * Waits a certain time.
+ *
+ * @param time Number of milliseconds.
+ */
+export function wait(time: number): Promise<void> {
+    return new Promise((resolve) => {
+        setTimeout(() => {
+            resolve();
+        }, time);
+    });
+}