From 7801f8a56874692154e187d85ec6908ee0b7e2de Mon Sep 17 00:00:00 2001
From: Brett Kyle <brett.kyle@digital.cabinet-office.gov.uk>
Date: Tue, 5 Sep 2023 14:22:42 +0100
Subject: [PATCH] Throw MissingElementError if key HTML missing

---
 src/govuk/components/skip-link/skip-link.mjs     |  3 ++-
 src/govuk/components/skip-link/skip-link.test.js | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/govuk/components/skip-link/skip-link.mjs b/src/govuk/components/skip-link/skip-link.mjs
index 4c15ca2669..cae167bc0f 100644
--- a/src/govuk/components/skip-link/skip-link.mjs
+++ b/src/govuk/components/skip-link/skip-link.mjs
@@ -1,3 +1,4 @@
+import { MissingElementError } from '../../errors/index.mjs'
 import { GOVUKFrontendComponent } from '../../govuk-frontend-component.mjs'
 
 /**
@@ -33,7 +34,7 @@ export class SkipLink extends GOVUKFrontendComponent {
     // Check for linked element
     const $linkedElement = this.getLinkedElement()
     if (!$linkedElement) {
-      return
+      throw new MissingElementError('The linked HTML element does not exist')
     }
 
     this.$linkedElement = $linkedElement
diff --git a/src/govuk/components/skip-link/skip-link.test.js b/src/govuk/components/skip-link/skip-link.test.js
index ad065b1a65..14f708f74b 100644
--- a/src/govuk/components/skip-link/skip-link.test.js
+++ b/src/govuk/components/skip-link/skip-link.test.js
@@ -81,5 +81,19 @@ describe('Skip Link', () => {
         message: 'GOV.UK Frontend is not supported in this browser'
       })
     })
+
+    it('throws when the linked element is missing', async () => {
+      await expect(
+        renderAndInitialise(page, 'skip-link', {
+          params: {
+            text: 'Skip to main content',
+            href: '#this-element-does-not-exist'
+          }
+        })
+      ).rejects.toEqual({
+        name: 'MissingElementError',
+        message: 'The linked HTML element does not exist'
+      })
+    })
   })
 })