[feat]: Add A11y aria-proptypes check (#6978)

* Add aria prop type list * feat: check aria attribute types * feat: add proptype tests * Add documentation * use aria-query Co-authored-by: Nurassyl Zekenov <[email protected]> Co-authored-by: [email protected] <[email protected]> Co-authored-by: tanhauhau <[email protected]> Co-authored-by: David Mosher <[email protected]>
sveltejs · Jul 11, 2022 · 3990198 · 3990198
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diff --git a/site/content/docs/05-accessibility-warnings.md b/site/content/docs/05-accessibility-warnings.md
@@ -98,6 +98,18 @@ Enforce img alt attribute does not contain the word image, picture, or photo. Sc
 
 ---
 
+### `a11y-incorrect-aria-attribute-type`
+
+Enforce that only the correct type of value is used for aria attributes. For example, `aria-hidden`
+should only receive a boolean.
+
+```sv
+<!-- A11y: The value of 'aria-hidden' must be exactly one of true or false -->
+<div aria-hidden="yes"/>
+```
+
+---
+
 ### `a11y-invalid-attribute`
 
 Enforce that attributes important for accessibility have a valid value. For example, `href` should not be empty, `'#'`, or `javascript:`.

diff --git a/src/compiler/compile/compiler_warnings.ts b/src/compiler/compile/compiler_warnings.ts
@@ -1,12 +1,14 @@
 // All compiler warnings should be listed and accessed from here
 
+import { ARIAPropertyDefinition } from 'aria-query';
+
 /**
  * @internal
  */
 export default {
 	custom_element_no_tag: {
 		code: 'custom-element-no-tag',
-		message: 'No custom element \'tag\' option was specified. To automatically register a custom element, specify a name with a hyphen in it, e.g. <svelte:options tag="my-thing"/>. To hide this warning, use <svelte:options tag={null}/>'			
+		message: 'No custom element \'tag\' option was specified. To automatically register a custom element, specify a name with a hyphen in it, e.g. <svelte:options tag="my-thing"/>. To hide this warning, use <svelte:options tag={null}/>'
 	},
 	unused_export_let: (component: string, property: string) => ({
 		code: 'unused-export-let',
@@ -60,6 +62,35 @@ export default {
 		code: 'a11y-aria-attributes',
 		message: `A11y: <${name}> should not have aria-* attributes`
 	}),
+	a11y_incorrect_attribute_type: (schema: ARIAPropertyDefinition, attribute: string) => {
+		let message;
+		switch (schema.type) {
+			case 'boolean':
+				message = `The value of '${attribute}' must be exactly one of true or false`;
+				break;
+			case 'id':
+				message = `The value of '${attribute}' must be a string that represents a DOM element ID`;
+				break;
+			case 'idlist':
+				message = `The value of '${attribute}' must be a space-separated list of strings that represent DOM element IDs`;
+				break;
+			case 'tristate':
+				message = `The value of '${attribute}' must be exactly one of true, false, or mixed`;
+				break;
+			case 'token':
+				message = `The value of '${attribute}' must be exactly one of ${(schema.values || []).join(', ')}`;
+				break;
+			case 'tokenlist':
+				message = `The value of '${attribute}' must be a space-separated list of one or more of ${(schema.values || []).join(', ')}`;
+				break;
+			default:
+				message = `The value of '${attribute}' must be of type ${schema.type}`;
+		}
+		return {
+			code: 'a11y-incorrect-aria-attribute-type',
+			message: `A11y: ${message}`
+		};
+	},
 	a11y_unknown_aria_attribute: (attribute: string, suggestion?: string) => ({
 		code: 'a11y-unknown-aria-attribute',
 		message: `A11y: Unknown aria attribute 'aria-${attribute}'` + (suggestion ? ` (did you mean '${suggestion}'?)` : '')

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
@@ -23,7 +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';
+import { ARIARoleDefintionKey, roles, aria, ARIAPropertyDefinition, ARIAProperty } 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)$/;
 
@@ -177,6 +177,32 @@ function get_namespace(parent: Element, element: Element, explicit_namespace: st
 	return parent_element.namespace;
 }
 
+function is_valid_aria_attribute_value(schema: ARIAPropertyDefinition, value: string | boolean): boolean {
+	switch (schema.type) {
+		case 'boolean':
+			return typeof value === 'boolean';
+		case 'string':
+		case 'id':
+			return typeof value === 'string';
+		case 'tristate':
+			return typeof value === 'boolean' || value === 'mixed';
+		case 'integer':
+		case 'number':
+			return typeof value !== 'boolean' && isNaN(Number(value)) === false;
+		case 'token': // single token
+			return (schema.values || [])
+				.indexOf(typeof value === 'string' ? value.toLowerCase() : value) > -1;
+		case 'idlist': // if list of ids, split each
+			return typeof value === 'string'
+				&& value.split(' ').every((id) => typeof id === 'string');
+		case 'tokenlist': // if list of tokens, split each
+			return typeof value === 'string'
+				&& value.split(' ').every((token) => (schema.values || []).indexOf(token.toLowerCase()) > -1);
+		default:
+			return false;
+	}
+}
+
 export default class Element extends Node {
 	type: 'Element';
 	name: string;
@@ -431,6 +457,18 @@ export default class Element extends Node {
 				if (name === 'aria-hidden' && /^h[1-6]$/.test(this.name)) {
 					component.warn(attribute, compiler_warnings.a11y_hidden(this.name));
 				}
+
+				// aria-proptypes
+				let value = attribute.get_static_value();
+				if (value === 'true') value = true;
+				if (value === 'false') value = false;
+
+				if (value !== null && value !== undefined && aria.has(name as ARIAProperty)) {
+					const schema = aria.get(name as ARIAProperty);
+					if (!is_valid_aria_attribute_value(schema, value)) {
+						component.warn(attribute, compiler_warnings.a11y_incorrect_attribute_type(schema, name));
+					}
+				}
 			}
 
 			// aria-role

diff --git a/test/validator/samples/a11y-aria-proptypes-boolean/input.svelte b/test/validator/samples/a11y-aria-proptypes-boolean/input.svelte
@@ -0,0 +1,8 @@
+<script>
+    const abc = 'abc';
+</script>
+
+<button aria-disabled="yes"/>
+<button aria-disabled="no"/>
+<button aria-disabled={1234}/>
+<button aria-disabled={`${abc}`}/>
diff --git a/test/validator/samples/a11y-aria-proptypes-boolean/warnings.json b/test/validator/samples/a11y-aria-proptypes-boolean/warnings.json
@@ -0,0 +1,32 @@
+[
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-disabled' must be exactly one of true or false",
+    "start": {
+      "line": 5,
+      "column": 8,
+      "character": 51
+    },
+    "end": {
+      "line": 5,
+      "column": 27,
+      "character": 70
+    },
+    "pos": 51
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-disabled' must be exactly one of true or false",
+    "start": {
+      "line": 6,
+      "column": 8,
+      "character": 81
+    },
+    "end": {
+      "line": 6,
+      "column": 26,
+      "character": 99
+    },
+    "pos": 81
+  }
+]
diff --git a/test/validator/samples/a11y-aria-proptypes-integer/input.svelte b/test/validator/samples/a11y-aria-proptypes-integer/input.svelte
@@ -0,0 +1,7 @@
+<div aria-level="yes" />
+<div aria-level="no" />
+<div aria-level={`abc`} />
+<div aria-level={true} />
+<div aria-level />
+<div aria-level={"false"} />
+<div aria-level={!"false"} />
diff --git a/test/validator/samples/a11y-aria-proptypes-integer/warnings.json b/test/validator/samples/a11y-aria-proptypes-integer/warnings.json
@@ -0,0 +1,47 @@
+[
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-level' must be of type integer",
+    "start": {
+      "line": 1,
+      "column": 5,
+      "character": 5
+    },
+    "end": {
+      "line": 1,
+      "column": 21,
+      "character": 21
+    },
+    "pos": 5
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-level' must be of type integer",
+    "start": {
+      "line": 2,
+      "column": 5,
+      "character": 30
+    },
+    "end": {
+      "line": 2,
+      "column": 20,
+      "character": 45
+    },
+    "pos": 30
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-level' must be of type integer",
+    "start": {
+      "line": 5,
+      "column": 5,
+      "character": 107
+    },
+    "end": {
+      "line": 5,
+      "column": 15,
+      "character": 117
+    },
+    "pos": 107
+  }
+]
diff --git a/test/validator/samples/a11y-aria-proptypes-number/input.svelte b/test/validator/samples/a11y-aria-proptypes-number/input.svelte
@@ -0,0 +1,7 @@
+<div aria-valuemax="yes" />
+<div aria-valuemax="no" />
+<div aria-valuemax={`abc`} />
+<div aria-valuemax={true} />
+<div aria-valuemax />
+<div aria-valuemax={'false'} />
+<div aria-valuemax={!'false'} />
diff --git a/test/validator/samples/a11y-aria-proptypes-number/warnings.json b/test/validator/samples/a11y-aria-proptypes-number/warnings.json
@@ -0,0 +1,47 @@
+[
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-valuemax' must be of type number",
+    "start": {
+      "line": 1,
+      "column": 5,
+      "character": 5
+    },
+    "end": {
+      "line": 1,
+      "column": 24,
+      "character": 24
+    },
+    "pos": 5
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-valuemax' must be of type number",
+    "start": {
+      "line": 2,
+      "column": 5,
+      "character": 33
+    },
+    "end": {
+      "line": 2,
+      "column": 23,
+      "character": 51
+    },
+    "pos": 33
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-valuemax' must be of type number",
+    "start": {
+      "line": 5,
+      "column": 5,
+      "character": 119
+    },
+    "end": {
+      "line": 5,
+      "column": 18,
+      "character": 132
+    },
+    "pos": 119
+  }
+]
diff --git a/test/validator/samples/a11y-aria-proptypes-string/input.svelte b/test/validator/samples/a11y-aria-proptypes-string/input.svelte
@@ -0,0 +1,5 @@
+<div aria-label />
+<div aria-label={true} />
+<div aria-label={false} />
+<div aria-label={1234} />
+<div aria-label={!true} />
diff --git a/test/validator/samples/a11y-aria-proptypes-string/warnings.json b/test/validator/samples/a11y-aria-proptypes-string/warnings.json
@@ -0,0 +1,17 @@
+[
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-label' must be of type string",
+    "start": {
+      "line": 1,
+      "column": 5,
+      "character": 5
+    },
+    "end": {
+      "line": 1,
+      "column": 15,
+      "character": 15
+    },
+    "pos": 5
+  }
+]
diff --git a/test/validator/samples/a11y-aria-proptypes-token/input.svelte b/test/validator/samples/a11y-aria-proptypes-token/input.svelte
@@ -0,0 +1,6 @@
+<div aria-sort="" />
+<div aria-sort="descnding" />
+<div aria-sort />
+<div aria-sort={true} />
+<div aria-sort={"false"} />
+<div aria-sort="ascending descending" />
diff --git a/test/validator/samples/a11y-aria-proptypes-token/warnings.json b/test/validator/samples/a11y-aria-proptypes-token/warnings.json
@@ -0,0 +1,62 @@
+[
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-sort' must be exactly one of ascending, descending, none, other",
+    "start": {
+      "line": 1,
+      "column": 5,
+      "character": 5
+    },
+    "end": {
+      "line": 1,
+      "column": 17,
+      "character": 17
+    },
+    "pos": 5
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-sort' must be exactly one of ascending, descending, none, other",
+    "start": {
+      "line": 2,
+      "column": 5,
+      "character": 26
+    },
+    "end": {
+      "line": 2,
+      "column": 26,
+      "character": 47
+    },
+    "pos": 26
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-sort' must be exactly one of ascending, descending, none, other",
+    "start": {
+      "line": 3,
+      "column": 5,
+      "character": 56
+    },
+    "end": {
+      "line": 3,
+      "column": 14,
+      "character": 65
+    },
+    "pos": 56
+  },
+  {
+    "code": "a11y-incorrect-aria-attribute-type",
+    "message": "A11y: The value of 'aria-sort' must be exactly one of ascending, descending, none, other",
+    "start": {
+      "line": 6,
+      "column": 5,
+      "character": 127
+    },
+    "end": {
+      "line": 6,
+      "column": 37,
+      "character": 159
+    },
+    "pos": 127
+  }
+]
diff --git a/test/validator/samples/a11y-aria-proptypes-tokenlist/input.svelte b/test/validator/samples/a11y-aria-proptypes-tokenlist/input.svelte
@@ -0,0 +1,7 @@
+<div aria-relevant="" />
+<div aria-relevant="foobar" />
+<div aria-relevant />
+<div aria-relevant={true} />
+<div aria-relevant={"false"} />
+<div aria-relevant="additions removalss" />
+<div aria-relevant="additions removalss " />