fix: don't warn about redundant `link` role on `<area>` without `href` (#18872)

Since #11737, `<a role="link">` without an `href` no longer triggers
`a11y_no_redundant_roles`, but `<area role="link">` without an `href`
still does. Per [ARIA in
HTML](https://www.w3.org/TR/html-aria/#el-area-no-href), an `<area>`
without `href` has the implicit role `generic` and `link` is one of its
allowed roles, so the role isn't redundant. This applies the existing
`<a>` exception to `<area>` and adds test cases for `<area>` with and
without `href`.

Closes #9261. The `<a>` example in that issue was already fixed by
#11737, but the issue was left open.

### Before submitting the PR, please make sure you do the following

- [x] It's really useful if your PR references an issue where it is
discussed ahead of time. In many cases, features are absent for a
reason. For large changes, please create an RFC:
https://github.com/sveltejs/rfcs
- [x] Prefix your PR title with `feat:`, `fix:`, `chore:`, or `docs:`.
- [x] This message body should clearly illustrate what problems it
solves.
- [x] Ideally, include a test that fails without this PR but passes with
it.
- [x] If this PR changes code within `packages/svelte/src`, add a
changeset (`npx changeset`).

### Tests and linting

- [x] Run the tests with `pnpm test` and lint the project with `pnpm
lint`

.changeset/quiet-areas-link.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: don't warn about a redundant `link` role on `<area>` elements without an `href`

packages/svelte/src/compiler/phases/2-analyze/visitors/shared/a11y/index.js

@@ -173,8 +173,8 @@ export function check_element(node, context) {
 						current_role === get_implicit_role(node.name, attribute_map) &&
 						// <ul role="list"> is ok because CSS list-style:none removes the semantics and this is a way to bring them back
 						!['ul', 'ol', 'li', 'menu'].includes(node.name) &&
-						// <a role="link" /> is ok because without href the a tag doesn't have a role of link
+						// <a role="link" /> and <area role="link" /> are ok because without href they don't have a role of link
-						!(node.name === 'a' && !attribute_map.has('href'))
+						!((node.name === 'a' || node.name === 'area') && !attribute_map.has('href'))
 					) {
 						w.a11y_no_redundant_roles(attribute, current_role);
 					}

packages/svelte/tests/validator/samples/a11y-no-redundant-roles/input.svelte

@@ -43,6 +43,11 @@
 <header role="banner"></header>
 <footer role="contentinfo"></footer>
 
+<!-- area with href has an implicit role of link -->
+<area href="/" role="link" alt="foo" />
+
 <!-- Allowed -->
 <!-- menu has same interactive role exceptions as ul/ol -->
 <menu role="menu"></menu>
+<!-- area without href doesn't have a role of link, same as a without href -->
+<area role="link" aria-label="foo" />

packages/svelte/tests/validator/samples/a11y-no-redundant-roles/warnings.json

@@ -454,5 +454,17 @@
 			"column": 8,
 			"line": 44
 		}
+	},
+	{
+		"code": "a11y_no_redundant_roles",
+		"end": {
+			"column": 26,
+			"line": 47
+		},
+		"message": "Redundant role 'link'",
+		"start": {
+			"column": 15,
+			"line": 47
+		}
 	}
 ]