wip: move a11y to its on file

package.json

@@ -62,10 +62,13 @@
     "@typescript-eslint/parser": "^2.1.0",
     "acorn": "^7.0.0",
     "agadoo": "^1.1.0",
+    "aria-query": "^3.0.0",
+    "axobject-query": "^2.0.2",
     "c8": "^5.0.1",
     "code-red": "0.0.17",
     "codecov": "^3.5.0",
     "css-tree": "1.0.0-alpha22",
+    "emoji-regex": "^7.0.3",
     "eslint": "^6.3.0",
     "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-svelte3": "^2.7.3",

src/compiler/compile/nodes/Attribute.ts

@@ -7,6 +7,7 @@ import Text from './Text';
 import Expression from './shared/Expression';
 import TemplateScope from './shared/TemplateScope';
 import { x } from 'code-red';
+import validateA11y from '../utils/validate-a11y/Attribute';
 
 export default class Attribute extends Node {
 	type: 'Attribute';
@@ -60,6 +61,12 @@ export default class Attribute extends Node {
 					return expression;
 				});
 		}
+
+		this.validate();
+	}
+
+	validate() {
+		validateA11y(this);
 	}
 
 	get_dependencies() {
@@ -86,7 +93,11 @@ export default class Attribute extends Node {
 		}
 
 		let expression = this.chunks
-			.map(chunk => chunk.type === 'Text' ? string_literal(chunk.data) : chunk.manipulate(block))
+			.map(chunk =>
+				chunk.type === 'Text'
+					? string_literal(chunk.data)
+					: chunk.manipulate(block)
+			)
 			.reduce((lhs, rhs) => x`${lhs} + ${rhs}`);
 
 		if (this.chunks[0].type !== 'Text') {
@@ -95,16 +106,16 @@ export default class Attribute extends Node {
 
 		return expression;
 	}
-
+	
 	get_static_value() {
-		if (this.is_spread || this.dependencies.size > 0) return null;
-
-		return this.is_true
-			? true
-			: this.chunks[0]
-				// method should be called only when `is_static = true`
-				? (this.chunks[0] as Text).data
-				: '';
+		if (this.is_spread || this.dependencies.size > 0) return undefined;
+		if (this.is_true) return true;
+		if (this.is_static) return this.chunks[0] ? (this.chunks[0] as Text).data: '';
+		if (this.chunks[0]) {
+			const expression = (this.chunks[0] as Expression).node;
+			return evaluate_value(expression);
+		}
+		return undefined;
 	}
 
 	should_cache() {
@@ -116,3 +127,25 @@ export default class Attribute extends Node {
 				: true;
 	}
 }
+
+function evaluate_value(node) {
+	switch (node.type) {
+		case 'Literal':
+			return node.value;
+		case 'UnaryExpression':
+			switch (node.operator) {
+				case '~':
+					return ~evaluate_value(node.argument);
+				case '!':
+					return !evaluate_value(node.argument);
+				case '+':
+					return +evaluate_value(node.argument);
+				case '-':
+					return -evaluate_value(node.argument);
+			}
+			break;
+		case 'TemplateLiteral':
+			return node.quasis[0].value.cooked;
+	}
+	return undefined;
+}