Normalise CSS parse errors

src/generators/shared/processCss.js

@@ -1,31 +1,24 @@
-import parse from 'css-tree/lib/parser/index.js';
-import walk from 'css-tree/lib/utils/walk.js';
-
 const commentsPattern = /\/\*[\s\S]*?\*\//g;
 
 export default function processCss ( parsed, code ) {
 	const css = parsed.css.content.styles;
 	const offset = parsed.css.content.start;
 
-	const ast = parse( css, {
-		positions: true
-	});
-
 	const attr = `[svelte-${parsed.hash}]`;
 
-	walk.rules( ast, rule => {
-		rule.selector.children.each( selector => {
-			const start = selector.loc.start.offset;
-			const end = selector.loc.end.offset;
+	function transform ( rule ) {
+		rule.selector.children.forEach( selector => {
+			const start = selector.start - offset;
+			const end = selector.end - offset;
 
 			const selectorString = css.slice( start, end );
 
-			const firstToken = selector.children.head;
+			const firstToken = selector.children[0];
 
 			let transformed;
 
-			if ( firstToken.data.type === 'TypeSelector' ) {
-				const insert = firstToken.data.loc.end.offset;
+			if ( firstToken.type === 'TypeSelector' ) {
+				const insert = firstToken.end - offset;
 				const head = css.slice( start, insert );
 				const tail = css.slice( insert, end );
 
@@ -36,7 +29,19 @@ export default function processCss ( parsed, code ) {
 
 			code.overwrite( start + offset, end + offset, transformed );
 		});
-	});
+	}
+
+	function walk ( node ) {
+		if ( node.type === 'Rule' ) {
+			transform( node );
+		} else if ( node.children ) {
+			node.children.forEach( walk );
+		} else if ( node.block ) {
+			walk( node.block );
+		}
+	}
+
+	parsed.css.children.forEach( walk );
 
 	// remove comments. TODO would be nice if this was exposed in css-tree
 	let match;

src/parse/read/style.js

@@ -1,15 +1,43 @@
+import parse from 'css-tree/lib/parser/index.js';
+import walk from 'css-tree/lib/utils/walk.js';
+
 export default function readStyle ( parser, start, attributes ) {
 	const contentStart = parser.index;
 	const styles = parser.readUntil( /<\/style>/ );
 	const contentEnd = parser.index;
 
+	let ast;
+
+	try {
+		ast = parse( styles, {
+			positions: true,
+			offset: contentStart
+		});
+	} catch ( err ) {
+		if ( err.name === 'CssSyntaxError' ) {
+			parser.error( err.message, err.offset );
+		} else {
+			throw err;
+		}
+	}
+
+	// tidy up AST
+	walk.all( ast, node => {
+		if ( node.loc ) {
+			node.start = node.loc.start.offset;
+			node.end = node.loc.end.offset;
+			delete node.loc;
+		}
+	});
+
 	parser.eat( '</style>', true );
 	const end = parser.index;
 
 	return {
 		start,
 		end,
 		attributes,
+		children: JSON.parse( JSON.stringify( ast.children ) ),
 		content: {
 			start: contentStart,
 			end: contentEnd,

test/parse.js

@@ -16,7 +16,7 @@ describe( 'parse', () => {
 			const input = fs.readFileSync( `test/parser/${dir}/input.html`, 'utf-8' ).replace( /\s+$/, '' );
 
 			try {
-				const actual = svelte.parse( input );
+				const actual = JSON.parse( JSON.stringify( svelte.parse( input ) ) );
 				const expected = require( `./parser/${dir}/output.json` );
 
 				assert.deepEqual( actual.html, expected.html );

test/parser/css/output.json

@@ -29,7 +29,61 @@
 			"start": 23,
 			"end": 48,
 			"styles": "\n\tdiv {\n\t\tcolor: red;\n\t}\n"
-		}
+		},
+		"children": [
+			{
+				"type": "Rule",
+				"start": 25,
+				"end": 47,
+				"selector": {
+					"type": "SelectorList",
+					"start": 25,
+					"end": 28,
+					"children": [
+						{
+							"type": "Selector",
+							"start": 25,
+							"end": 28,
+							"children": [
+								{
+									"type": "TypeSelector",
+									"start": 25,
+									"end": 28,
+									"name": "div"
+								}
+							]
+						}
+					]
+				},
+				"block": {
+					"type": "Block",
+					"start": 29,
+					"end": 47,
+					"children": [
+						{
+							"type": "Declaration",
+							"start": 33,
+							"end": 43,
+							"important": false,
+							"property": "color",
+							"value": {
+								"type": "Value",
+								"start": 39,
+								"end": 43,
+								"children": [
+									{
+										"type": "Identifier",
+										"start": 40,
+										"end": 43,
+										"name": "red"
+									}
+								]
+							}
+						}
+					]
+				}
+			}
+		]
 	},
 	"js": null
 }

test/parser/error-css/error.json

@@ -0,0 +1,8 @@
+{
+	"message": "LeftCurlyBracket is expected",
+	"loc": {
+		"line": 2,
+		"column": 16
+	},
+	"pos": 24
+}

test/parser/error-css/input.html

@@ -0,0 +1,3 @@
+<style>
+	this is not css
+</style>