Add test for instrument highlights

client/cypress/e2e/frontend/modules/highlights.cy.ts

@@ -228,4 +228,27 @@ describe('Highlights', () => {
     cy.getByDataCy('highlight-note-text').should('contain.text', textPart);
     cy.get(`[href="${urlPart}"]`).should('exist');
   });
+
+  it.only('visits an instrument and highlights some text', () => {
+    cy.mockGraphqlOps({
+      operations: {
+        ...operations,
+        InstrumentQuery: {
+          instrument: {
+            title: 'My Instrument',
+            contents: [
+              {
+                type: 'text_block',
+                value: {
+                  text: '<p>Hello my beautiful World!</p>',
+                },
+              },
+            ],
+          },
+        },
+      },
+    });
+    cy.visit('/instrument/my-instrument');
+    markText();
+  });
 });