[a11y][Violation][4.1.2 Name, Role, Value] Some Notebook UI elements missing roles and labels

[nkn2022]

Description

I am running an accessibility test suite with Notebook UI using the IBM Equal Access Accessibility Checker tool on Chrome browser. The results look good overall, only a few things are missing to reach a first formal level of compliance. So kindly help look into these.

Issues reported were violating WCAG 2.2 requirements.
Ref: https://www.ibm.com/able/requirements/checker-rule-sets

Full report (includes information on element locations where issue were found):
Accessibility_Report-7a73e10e-f8a4-4a06-a78d-5174a1309c5b.xlsx

Category: 4.1.2 Name, Role, Value

Ref: https://www.ibm.com/able/requirements/requirements/?version=v7_3#4_1_2

Violation of Rule: element_tabbable_role_valid

List of issues with elements that violate this rule with a screenshots

Issue 1
The tabbable element's role 'generic' is not a widget role
Element location:
<div data-windowed-list-index="0" tabindex="0" aria-label="Code Cell Content with Output" class="lm-Widget jp-Cell jp-CodeCell jp-Notebook-cell jp-mod-selected jp-mod-active">

Issue 2
The tabbable element's role 'none' is not a widget role
Element location:
<jp-button minimal="" appearance="stealth" current-value="" tabindex="0" title="Create a duplicate of this cell below" data-command="notebook:duplicate-below" aria-label="Create a duplicate of this cell below" aria-disabled="false" class="jp-ToolbarButtonComponent">
Screenshot:

**Violation of Rule: input_label_exists

List of issues with elements that violate this rule with a screenshots

Issue 1
Form control with "textbox" role has no associated label
Element location:
<div data-language="python" style="tab-size: 4;" tabindex="-1" aria-multiline="true" role="textbox" class="cm-content" contenteditable="true" translate="no" autocapitalize="off" autocorrect="off" spellcheck="false">
Screenshot:

Reproduce

• Install Chrome extension for IBM accessibility checker tool. Ref: https://www.ibm.com/able/toolkit/verify/automated
• Open Notebook UI on Chrome browser. Add some cells with code.
• Run the tool and we can see the above Violations reported.

Here is the screenshot of the UI scanned for the attached report:

Expected behavior

Missing roles/labels are in place.
Reference on how to fix this issue can be found in these links:
Add accessible names for inputs lacking visible labels
If repurposing a standard component, use ARIA to set the correct name and role
On custom components, use ARIA to expose name, role, and value

[RRosio]

Linking jupyterlab/jupyterlab#16890 here.