Label the <button> using aria-labelledby

Reference the `<label>` and the `<button>` itself so there's no duplication
of content, ensuring that when translated, the accessible name matches what's
visible on the screen.

packages/govuk-frontend/src/govuk/components/file-upload/file-upload.mjs

@@ -61,7 +61,13 @@ export class FileUpload extends ConfigurableComponent {
       locale: closestAttributeValue(this.$root, 'lang')
     })
 
-    this.$label = this.findLabel()
+    const $label = this.findLabel()
+    $label.setAttribute('for', `${this.id}-input`)
+    // Add an ID to the label if it doesn't have one already
+    // so it can be referenced by `aria-labelledby`
+    if (!$label.id) {
+      $label.id = `${this.id}-label`
+    }
 
     // we need to copy the 'id' of the root element
     // to the new button replacement element
@@ -72,10 +78,6 @@ export class FileUpload extends ConfigurableComponent {
     const $wrapper = document.createElement('div')
     $wrapper.className = 'govuk-file-upload-wrapper'
 
-    const commaSpan = document.createElement('span')
-    commaSpan.className = 'govuk-visually-hidden'
-    commaSpan.innerText = ', '
-
     // Create the file selection button
     const $button = document.createElement('button')
     $button.classList.add('govuk-file-upload__button')
@@ -93,11 +95,16 @@ export class FileUpload extends ConfigurableComponent {
     const $status = document.createElement('span')
     $status.className = 'govuk-body govuk-file-upload__status'
     $status.innerText = this.i18n.t('filesSelectedDefault')
-    $status.setAttribute('aria-hidden', 'true')
     $status.classList.add('govuk-file-upload__status--empty')
 
     $button.appendChild($status)
-    $button.appendChild(commaSpan.cloneNode(true))
+
+    const commaSpan = document.createElement('span')
+    commaSpan.className = 'govuk-visually-hidden'
+    commaSpan.innerText = ', '
+    commaSpan.id = `${this.id}-comma`
+
+    $button.appendChild(commaSpan)
 
     const containerSpan = document.createElement('span')
     containerSpan.className = 'govuk-file-upload__pseudo-button-container'
@@ -106,10 +113,8 @@ export class FileUpload extends ConfigurableComponent {
     buttonSpan.className =
       'govuk-button govuk-button--secondary govuk-file-upload__pseudo-button'
     buttonSpan.innerText = this.i18n.t('selectFilesButton')
-    buttonSpan.setAttribute('aria-hidden', 'true')
 
     containerSpan.appendChild(buttonSpan)
-    containerSpan.appendChild(commaSpan.cloneNode(true))
 
     const instructionSpan = document.createElement('span')
     instructionSpan.className = 'govuk-body govuk-file-upload__instruction'
@@ -119,8 +124,8 @@ export class FileUpload extends ConfigurableComponent {
 
     $button.appendChild(containerSpan)
     $button.setAttribute(
-      'aria-label',
-      `${this.$label.innerText}, ${this.i18n.t('selectFilesButton')} ${this.i18n.t('instruction')}, ${$status.innerText}`
+      'aria-labelledby',
+      `${$label.id} ${commaSpan.id} ${$button.id}`
     )
     $button.addEventListener('click', this.onClick.bind(this))
 
@@ -144,7 +149,7 @@ export class FileUpload extends ConfigurableComponent {
     // Bind change event to the underlying input
     this.$root.addEventListener('change', this.onChange.bind(this))
 
-    // Syncronise the `disabled` state between the button and underlying input
+    // Synchronise the `disabled` state between the button and underlying input
     this.updateDisabledState()
     this.observeDisabledState()
 
@@ -271,11 +276,6 @@ export class FileUpload extends ConfigurableComponent {
 
       this.$status.classList.remove('govuk-file-upload__status--empty')
     }
-
-    this.$button.setAttribute(
-      'aria-label',
-      `${this.$label.innerText}, ${this.i18n.t('selectFilesButton')} ${this.i18n.t('instruction')}, ${this.$status.innerText}`
-    )
   }
 
   /**

packages/govuk-frontend/src/govuk/components/file-upload/file-upload.puppeteer.test.js

@@ -1,6 +1,9 @@
 /* eslint-disable no-new */
 
-const { render } = require('@govuk-frontend/helpers/puppeteer')
+const {
+  render,
+  getAccessibleName
+} = require('@govuk-frontend/helpers/puppeteer')
 const { getExamples } = require('@govuk-frontend/lib/components')
 
 const inputSelector = '.govuk-file-upload'
@@ -104,15 +107,8 @@ describe('/components/file-upload', () => {
               (el) => el.innerHTML.trim()
             )
 
-            const buttonAriaText = await page.$eval(buttonSelector, (el) =>
-              el.getAttribute('aria-label')
-            )
-
             expect(buttonElementText).toBe('Choose file')
             expect(statusElementText).toBe('No file chosen')
-            expect(buttonAriaText).toBe(
-              'Upload a file, Choose file or drop file, No file chosen'
-            )
           })
         })
       })
@@ -348,6 +344,61 @@ describe('/components/file-upload', () => {
         })
       })
 
+      describe('accessible name', () => {
+        beforeEach(async () => {})
+
+        it('includes the label, the status, the pseudo button and instruction', async () => {
+          await render(page, 'file-upload', examples.enhanced)
+
+          const $element = await page.$('.govuk-file-upload__button')
+
+          const accessibleName = await getAccessibleName(page, $element)
+          await expect(accessibleName.replaceAll(/\s+/g, ' ')).toBe(
+            'Upload a file , No file chosen , Choose file or drop file'
+          )
+        })
+
+        it('includes the label, file name, pseudo button and instruction once a file is selected', async () => {
+          await render(page, 'file-upload', examples.enhanced)
+
+          const $element = await page.$('.govuk-file-upload__button')
+
+          const [fileChooser] = await Promise.all([
+            page.waitForFileChooser(),
+            page.click(buttonSelector)
+          ])
+          await fileChooser.accept(['fakefile.txt'])
+
+          const accessibleName = await getAccessibleName(page, $element)
+          await expect(accessibleName.replaceAll(/\s+/g, ' ')).toBe(
+            'Upload a file , fakefile.txt , Choose file or drop file'
+          )
+        })
+
+        it('includes the label, file name, pseudo button and instruction once a file is selected', async () => {
+          await render(page, 'file-upload', examples.enhanced, {
+            beforeInitialisation() {
+              document
+                .querySelector('[type="file"]')
+                .setAttribute('multiple', '')
+            }
+          })
+
+          const $element = await page.$('.govuk-file-upload__button')
+
+          const [fileChooser] = await Promise.all([
+            page.waitForFileChooser(),
+            page.click(buttonSelector)
+          ])
+          await fileChooser.accept(['fakefile1.txt', 'fakefile2.txt'])
+
+          const accessibleName = await getAccessibleName(page, $element)
+          await expect(accessibleName.replaceAll(/\s+/g, ' ')).toBe(
+            'Upload a file , 2 files chosen , Choose file or drop file'
+          )
+        })
+      })
+
       describe('i18n', () => {
         beforeEach(async () => {
           await render(page, 'file-upload', examples.translated)
@@ -363,15 +414,8 @@ describe('/components/file-upload', () => {
             el.innerHTML.trim()
           )
 
-          const buttonAriaText = await page.$eval(buttonSelector, (el) =>
-            el.getAttribute('aria-label')
-          )
-
           expect(buttonElementText).toBe('Dewiswch ffeil')
           expect(statusElementText).toBe("Dim ffeiliau wedi'u dewis")
-          expect(buttonAriaText).toBe(
-            "Llwythwch ffeil i fyny, Dewiswch ffeil neu ollwng ffeil, Dim ffeiliau wedi'u dewis"
-          )
         })
 
         describe('status element', () => {