Add cypress tests for partial page load on vocab home page

cypress/e2e/vocab-home.cy.js

@@ -1,11 +1,34 @@
 describe('Vocabulary home page', () => {
-  it('contains vocabulary title', () => {
-    // go to the Skosmos front page
-    cy.visit('/')
-    // click on the first vocabulary in the list
-    cy.get('#vocabulary-list').find('a').first().click()
+  // using context because otherwise cypress would not clear the state and tests couldn't be run independently
+  context('Vocabulary home page', () => {
+    it('contains vocabulary title', () => {
+      // go to the Skosmos front page
+      cy.visit('/')
+      // click on the first vocabulary in the list
+      cy.get('#vocabulary-list').find('a').first().click()
+
+      // check that the vocabulary title is not empty
+      cy.get('#vocab-title > a').invoke('text').should('match', /.+/)
+    })
+  })
+
+  context('partial page load', () => {
+    it('does a partial page load', () => {
+      // go to the YSO home page (Allärs does not have an index in the backend for some reason)
+      cy.visit('/yso/en')
+      // click on the first concept in the alphabetical index
+      cy.get('#alpha-list').find('a').first().click()
+      // check that the term heading exists
+      cy.get('#term-heading')
+    })
 
-    // check that the vocabulary title is not empty
-    cy.get('#vocab-title > a').invoke('text').should('match', /.+/)
+    it('updates mappings component after partial page load', () => {
+      // go to the YSO home page
+      cy.visit('/yso/en')
+      // click on the first concept in the alphabetical index
+      cy.get('#alpha-list').find('a').first().click()
+      // check that concept mappings is not empty
+      cy.get('#concept-mappings').should('not.be.empty')
+    })
   })
 })