Align R18 with specification

.changeset/violet-coats-tie.md

@@ -0,0 +1,5 @@
+---
+"@siteimprove/alfa-rules": minor
+---
+
+**Fixed:** SIA-R18 now accepts attributes for `input type=file` and `input type=color` according to the [ARIA in HTML](https://w3c.github.io/html-aria/#el-input-file) specification

packages/alfa-aria/src/feature.ts

@@ -399,6 +399,7 @@ const Features: Features = {
             return element.attribute("list").isSome()
               ? "combobox"
               : "searchbox";
+          // Note: The specification for email has changed, it now has role textbox. We should look into this if it becomes an issue.
           case "email":
           case "tel":
           case "text":

packages/alfa-rules/src/sia-r18/rule.ts

@@ -70,6 +70,33 @@ export default Rule.Atomic.of<Page, Attribute>({
   },
 });
 
+function allowedForInputType(
+  attributeName: aria.Attribute.Name,
+): Predicate<Element> {
+  return hasInputType((inputType) => {
+    switch (inputType) {
+      case "color":
+        return attributeName === "aria-disabled";
+      case "date":
+      case "datetime-local":
+      case "email":
+      case "month":
+      case "password":
+      case "time":
+      case "week":
+        return Role.of("textbox").isAttributeSupported(attributeName);
+      case "file":
+        return (
+          attributeName === "aria-disabled" ||
+          attributeName === "aria-invalid" ||
+          attributeName === "aria-required"
+        );
+      default:
+        return false;
+    }
+  });
+}
+
 function ariaHtmlAllowed(target: Attribute): boolean {
   const attributeName = target.name as aria.Attribute.Name;
   for (const element of target.owner) {
@@ -78,17 +105,7 @@ function ariaHtmlAllowed(target: Attribute): boolean {
         return Role.of("document").isAttributeSupported(attributeName);
 
       case "input":
-        return (
-          hasInputType(
-            "date",
-            "datetime-local",
-            "email",
-            "month",
-            "password",
-            "time",
-            "week",
-          )(element) && Role.of("textbox").isAttributeSupported(attributeName)
-        );
+        return allowedForInputType(attributeName)(element);
 
       case "select":
         return (

packages/alfa-rules/test/sia-r18/rule.spec.tsx

@@ -23,6 +23,58 @@ test(`evaluate() passes input with type password field and aria-required state`,
   ]);
 });
 
+test(`evaluate() passes input with type file field and aria-disabled state`, async (t) => {
+  const target = <input type="file" aria-disabled="true" />;
+
+  const document = h.document([target]);
+
+  t.deepEqual(await evaluate(R18, { document }), [
+    passed(R18, target.attribute("aria-disabled").getUnsafe(), {
+      1: Outcomes.IsAllowed,
+      2: Outcomes.IsNotProhibited,
+    }),
+  ]);
+});
+
+test(`evaluate() passes input with type file field and aria-invalid state`, async (t) => {
+  const target = <input type="file" aria-invalid="true" />;
+
+  const document = h.document([target]);
+
+  t.deepEqual(await evaluate(R18, { document }), [
+    passed(R18, target.attribute("aria-invalid").getUnsafe(), {
+      1: Outcomes.IsAllowed,
+      2: Outcomes.IsNotProhibited,
+    }),
+  ]);
+});
+
+test(`evaluate() passes input with type file field and aria-required state`, async (t) => {
+  const target = <input type="file" aria-required="true" />;
+
+  const document = h.document([target]);
+
+  t.deepEqual(await evaluate(R18, { document }), [
+    passed(R18, target.attribute("aria-required").getUnsafe(), {
+      1: Outcomes.IsAllowed,
+      2: Outcomes.IsNotProhibited,
+    }),
+  ]);
+});
+
+test(`evaluate() passes input with type color field and aria-disabled state`, async (t) => {
+  const target = <input type="color" aria-disabled="true" />;
+
+  const document = h.document([target]);
+
+  t.deepEqual(await evaluate(R18, { document }), [
+    passed(R18, target.attribute("aria-disabled").getUnsafe(), {
+      1: Outcomes.IsAllowed,
+      2: Outcomes.IsNotProhibited,
+    }),
+  ]);
+});
+
 test(`evaluate() passes a button with aria-pressed state`, async (t) => {
   const target = <button aria-pressed="false">My button</button>;