From b816c399d79b77e0027d7a5615766fc498c03193 Mon Sep 17 00:00:00 2001
From: Thomas Marshall <thomas@thomasmarshall.com>
Date: Tue, 3 Nov 2020 13:46:37 +0000
Subject: [PATCH 1/2] Ensure hidden inputs are not labelable

The `labels` property on `input` elements of type `hidden` is `null`
rather than `NodeList` [1]. This meant the `getRealLabels` function
would return `null` causing `queryAllByLabelText` to throw an error when
it tried to call `length` on `null` [2].

This commit fixes the issue by ensuring the element is labelable before
calling `labels` on it, and adds a test case for this specific scenario.

[1]: https://html.spec.whatwg.org/multipage/forms.html#dom-lfe-labels
[2]: https://github.com/testing-library/dom-testing-library/blob/62f4e5e09a4b81ef66679560b540523edccdef98/src/queries/label-text.js#L52
---
 src/__tests__/label-helpers.js | 7 +++++++
 src/__tests__/queries.find.js  | 1 +
 src/label-helpers.js           | 4 ++--
 3 files changed, 10 insertions(+), 2 deletions(-)
 create mode 100644 src/__tests__/label-helpers.js

diff --git a/src/__tests__/label-helpers.js b/src/__tests__/label-helpers.js
new file mode 100644
index 00000000..4fd2448f
--- /dev/null
+++ b/src/__tests__/label-helpers.js
@@ -0,0 +1,7 @@
+import {getRealLabels} from '../label-helpers'
+
+test('hidden inputs are not labelable', () => {
+  const element = document.createElement('input')
+  element.type = 'hidden'
+  expect(getRealLabels(element)).toEqual([])
+})
diff --git a/src/__tests__/queries.find.js b/src/__tests__/queries.find.js
index f8c48f1f..6372f957 100644
--- a/src/__tests__/queries.find.js
+++ b/src/__tests__/queries.find.js
@@ -35,6 +35,7 @@ test('find asynchronously finds elements', async () => {
       <div role="dialog"></div>
       <div role="meter progressbar"></div>
       <header>header</header>
+      <input type="hidden" />
     </div>
   `)
   await expect(findByLabelText('test-label')).resolves.toBeTruthy()
diff --git a/src/label-helpers.js b/src/label-helpers.js
index 52c5dc99..d1711edb 100644
--- a/src/label-helpers.js
+++ b/src/label-helpers.js
@@ -34,10 +34,10 @@ function getLabelContent(node) {
 
 // Based on https://github.com/eps1lon/dom-accessibility-api/pull/352
 function getRealLabels(element) {
-  if (element.labels !== undefined) return element.labels
-
   if (!isLabelable(element)) return []
 
+  if (element.labels !== undefined) return element.labels
+
   const labels = element.ownerDocument.querySelectorAll('label')
   return Array.from(labels).filter(label => label.control === element)
 }

From a6605d17c440435fc134656d579d28478b428778 Mon Sep 17 00:00:00 2001
From: Thomas Marshall <thomas@thomasmarshall.com>
Date: Tue, 3 Nov 2020 18:49:51 +0000
Subject: [PATCH 2/2] squash! Ensure hidden inputs are not labelable

This commit fixes the issue by retuning an empty array if the `labels`
property is `null`, and adds a test case for this specific scenario.
---
 src/label-helpers.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/label-helpers.js b/src/label-helpers.js
index d1711edb..d71b4f8e 100644
--- a/src/label-helpers.js
+++ b/src/label-helpers.js
@@ -34,9 +34,9 @@ function getLabelContent(node) {
 
 // Based on https://github.com/eps1lon/dom-accessibility-api/pull/352
 function getRealLabels(element) {
-  if (!isLabelable(element)) return []
+  if (element.labels !== undefined) return element.labels ?? []
 
-  if (element.labels !== undefined) return element.labels
+  if (!isLabelable(element)) return []
 
   const labels = element.ownerDocument.querySelectorAll('label')
   return Array.from(labels).filter(label => label.control === element)