a11y: Add role-has-required-aria-props rule

package.json

@@ -124,12 +124,14 @@
     "@rollup/plugin-typescript": "^2.0.1",
     "@rollup/plugin-virtual": "^2.0.0",
     "@sveltejs/eslint-config": "github:sveltejs/eslint-config#v5.8.0",
+    "@types/aria-query": "^5.0.0",
     "@types/mocha": "^7.0.0",
     "@types/node": "^8.10.53",
     "@typescript-eslint/eslint-plugin": "^5.22.0",
     "@typescript-eslint/parser": "^5.22.0",
     "acorn": "^8.4.1",
     "agadoo": "^1.1.0",
+    "aria-query": "^5.0.0",
     "code-red": "^0.2.5",
     "css-tree": "^1.1.2",
     "eslint": "^8.0.0",

src/compiler/compile/compiler_warnings.ts

@@ -80,6 +80,10 @@ export default {
 		code: 'a11y-no-redundant-roles',
 		message: `A11y: Redundant role '${role}'`
 	}),
+	a11y_role_has_required_aria_props: (role: string, props: string[]) => ({
+		code: 'a11y-role-has-required-aria-props',
+		message: `A11y: Elements with the ARIA role "${role}" must have the following attributes defined: ${props.map(name => `"${name}"`).join(', ')}`
+	}),
 	a11y_accesskey: {
 		code: 'a11y-accesskey',
 		message: 'A11y: Avoid using accesskey'

src/compiler/compile/nodes/Element.ts

@@ -23,6 +23,7 @@ import { string_literal } from '../utils/stringify';
 import { Literal } from 'estree';
 import compiler_warnings from '../compiler_warnings';
 import compiler_errors from '../compiler_errors';
+import { ARIARoleDefintionKey, roles } from 'aria-query';
 
 const svg = /^(?:altGlyph|altGlyphDef|altGlyphItem|animate|animateColor|animateMotion|animateTransform|circle|clipPath|color-profile|cursor|defs|desc|discard|ellipse|feBlend|feColorMatrix|feComponentTransfer|feComposite|feConvolveMatrix|feDiffuseLighting|feDisplacementMap|feDistantLight|feDropShadow|feFlood|feFuncA|feFuncB|feFuncG|feFuncR|feGaussianBlur|feImage|feMerge|feMergeNode|feMorphology|feOffset|fePointLight|feSpecularLighting|feSpotLight|feTile|feTurbulence|filter|font|font-face|font-face-format|font-face-name|font-face-src|font-face-uri|foreignObject|g|glyph|glyphRef|hatch|hatchpath|hkern|image|line|linearGradient|marker|mask|mesh|meshgradient|meshpatch|meshrow|metadata|missing-glyph|mpath|path|pattern|polygon|polyline|radialGradient|rect|set|solidcolor|stop|svg|switch|symbol|text|textPath|tref|tspan|unknown|use|view|vkern)$/;
 
@@ -407,9 +408,9 @@ export default class Element extends Node {
 	}
 
 	validate_attributes_a11y() {
-		const { component } = this;
+		const { component, attributes } = this;
 
-		this.attributes.forEach(attribute => {
+		attributes.forEach(attribute => {
 			if (attribute.is_spread) return;
 
 			const name = attribute.name.toLowerCase();
@@ -462,6 +463,17 @@ export default class Element extends Node {
 						component.warn(attribute, compiler_warnings.a11y_no_redundant_roles(value));
 					}
 				}
+
+				// role-has-required-aria-props
+				const role = roles.get(value as ARIARoleDefintionKey);
+				if (role) {
+					const required_role_props = Object.keys(role.requiredProps);
+					const has_missing_props = required_role_props.some(prop => !attributes.find(a => a.name === prop));
+
+					if (has_missing_props) {
+						component.warn(attribute, compiler_warnings.a11y_role_has_required_aria_props(value as string, required_role_props));
+					}
+				}
 			}
 
 			// no-access-key

test/validator/samples/a11y-role-has-required-aria-props/input.svelte

@@ -0,0 +1,9 @@
+<div role="heading"></div>
+<span role="checkbox"></span>
+<div role="meter"></div>
+<div role="scrollbar"></div>
+
+<div role="heading" aria-level="1"></div>
+<span role="checkbox" aria-checked="false"></span>
+<div role="meter" aria-valuenow="50" aria-valuemin="0" aria-valuemax="100"></div>
+<div role="scrollbar" aria-controls="panel" aria-valuenow="50"></div>

test/validator/samples/a11y-role-has-required-aria-props/warnings.json

@@ -0,0 +1,62 @@
+[
+	{
+		"code": "a11y-role-has-required-aria-props",
+		"message": "A11y: Elements with the ARIA role \"heading\" must have the following attributes defined: \"aria-level\"",
+		"start": {
+			"line": 1,
+			"column": 5,
+			"character": 5
+		},
+		"end": {
+			"line": 1,
+			"column": 19,
+			"character": 19
+		},
+		"pos": 5
+	},
+	{
+		"code": "a11y-role-has-required-aria-props",
+		"message": "A11y: Elements with the ARIA role \"checkbox\" must have the following attributes defined: \"aria-checked\"",
+		"start": {
+			"line": 2,
+			"column": 6,
+			"character": 33
+		},
+		"end": {
+			"line": 2,
+			"column": 21,
+			"character": 48
+		},
+		"pos": 33
+	},
+	{
+		"code": "a11y-role-has-required-aria-props",
+		"message": "A11y: Elements with the ARIA role \"meter\" must have the following attributes defined: \"aria-valuenow\"",
+		"start": {
+			"line": 3,
+			"column": 5,
+			"character": 62
+		},
+		"end": {
+			"line": 3,
+			"column": 17,
+			"character": 74
+		},
+		"pos": 62
+	},
+	{
+		"code": "a11y-role-has-required-aria-props",
+		"message": "A11y: Elements with the ARIA role \"scrollbar\" must have the following attributes defined: \"aria-controls\", \"aria-valuenow\"",
+		"start": {
+			"character": 87,
+			"column": 5,
+			"line": 4
+		},
+		"end": {
+			"character": 103,
+			"column": 21,
+			"line": 4
+		},
+		"pos": 87
+	}
+]