2 files changed, 55 insertions, 13 deletions

diff --git a/packages/browser/src/helpers/webAuthnAbortService.test.ts b/packages/browser/src/helpers/webAuthnAbortService.test.ts
index 506bb2a..87d2535 100644
--- a/packages/browser/src/helpers/webAuthnAbortService.test.ts
+++ b/packages/browser/src/helpers/webAuthnAbortService.test.ts
@@ -1,23 +1,23 @@
-import { webauthnAbortService } from './webAuthnAbortService';
+import { WebAuthnAbortService } from './webAuthnAbortService';
 
 test('should create a new abort signal every time', () => {
-  const signal1 = webauthnAbortService.createNewAbortSignal();
-  const signal2 = webauthnAbortService.createNewAbortSignal();
+  const signal1 = WebAuthnAbortService.createNewAbortSignal();
+  const signal2 = WebAuthnAbortService.createNewAbortSignal();
 
   expect(signal2).not.toBe(signal1);
 });
 
 test('should call abort() with AbortError on existing controller when creating a new signal', () => {
   // Populate `.controller`
-  webauthnAbortService.createNewAbortSignal();
+  WebAuthnAbortService.createNewAbortSignal();
 
   // Spy on the existing instance of AbortController
   const abortSpy = jest.fn();
   // @ts-ignore: Ignore the fact that `controller` is private
-  webauthnAbortService.controller.abort = abortSpy;
+  WebAuthnAbortService.controller.abort = abortSpy;
 
   // Generate a new signal, which should call `abort()` on the existing controller
-  webauthnAbortService.createNewAbortSignal();
+  WebAuthnAbortService.createNewAbortSignal();
   expect(abortSpy).toHaveBeenCalledTimes(1);
 
   // Make sure we raise an AbortError so it can be detected correctly
@@ -25,3 +25,26 @@ test('should call abort() with AbortError on existing controller when creating a
   expect(abortReason).toBeInstanceOf(Error);
   expect(abortReason.name).toEqual('AbortError');
 });
+
+test('should cancel active WebAuthn ceremony when manually cancelled', () => {
+  // Populate `.controller`
+  WebAuthnAbortService.createNewAbortSignal();
+
+  // Spy on the existing instance of AbortController
+  const abortSpy = jest.fn();
+  // @ts-ignore: Ignore the fact that `controller` is private
+  WebAuthnAbortService.controller.abort = abortSpy;
+
+  // Cancel the in-flight ceremony, which should call `abort()` on the existing controller
+  WebAuthnAbortService.cancelCeremony();
+  expect(abortSpy).toHaveBeenCalledTimes(1);
+
+  // Make sure we raise an AbortError so it can be detected correctly
+  const abortReason = abortSpy.mock.calls[0][0];
+  expect(abortReason).toBeInstanceOf(Error);
+  expect(abortReason.name).toEqual('AbortError');
+
+  // Ensure that we don't set up a new AbortController because it's unnecessary to do so
+  // @ts-ignore: Ignore the fact that `controller` is private
+  expect(WebAuthnAbortService.controller).toBeUndefined();
+});
diff --git a/packages/browser/src/helpers/webAuthnAbortService.ts b/packages/browser/src/helpers/webAuthnAbortService.ts
index 50e00ba..395ceea 100644
--- a/packages/browser/src/helpers/webAuthnAbortService.ts
+++ b/packages/browser/src/helpers/webAuthnAbortService.ts
@@ -1,13 +1,10 @@
-/**
- * A way to cancel an existing WebAuthn request, for example to cancel a
- * WebAuthn autofill authentication request for a manual authentication attempt.
- */
-class WebAuthnAbortService {
+class BaseWebAuthnAbortService {
   private controller: AbortController | undefined;
 
   /**
    * Prepare an abort signal that will help support multiple auth attempts without needing to
-   * reload the page
+   * reload the page. This is automatically called whenever `startRegistration()` and
+   * `startAuthentication()` are called.
    */
   createNewAbortSignal() {
     // Abort any existing calls to navigator.credentials.create() or navigator.credentials.get()
@@ -24,6 +21,28 @@ class WebAuthnAbortService {
     this.controller = newController;
     return newController.signal;
   }
+
+  /**
+   * Manually cancel any active WebAuthn registration or authentication attempt.
+   */
+  cancelCeremony() {
+    if (this.controller) {
+      const abortError = new Error(
+        'Manually cancelling existing WebAuthn API call',
+      );
+      abortError.name = 'AbortError';
+      this.controller.abort(abortError);
+
+      this.controller = undefined;
+    }
+  }
 }
 
-export const webauthnAbortService = new WebAuthnAbortService();
+/**
+ * A service singleton to help ensure that only a single WebAuthn ceremony is active at a time.
+ *
+ * Users of **@simplewebauthn/browser** shouldn't typically need to use this, but it can help e.g.
+ * developers building projects that use client-side routing to better control the behavior of
+ * their UX in response to router navigation events.
+ */
+export const WebAuthnAbortService = new BaseWebAuthnAbortService();