tidy and adjust error message

src/compiler/parse/index.ts

@@ -8,7 +8,7 @@ import error from '../utils/error';
 
 type ParserState = (parser: Parser) => (ParserState | void);
 
-interface LastAutoCloseTag {
+interface LastAutoClosedTag {
 	tag: string;
 	reason: string;
 	depth: number;
@@ -26,7 +26,7 @@ export class Parser {
 	css: Style[] = [];
 	js: Script[] = [];
 	meta_tags = {};
-	last_auto_closed_tag?: LastAutoCloseTag;
+	last_auto_closed_tag?: LastAutoClosedTag;
 
 	constructor(template: string, options: ParserOptions) {
 		if (typeof template !== 'string') {

src/compiler/parse/state/tag.ts

@@ -134,16 +134,12 @@ export default function tag(parser: Parser) {
 		// close any elements that don't have their own closing tags, e.g. <div><p></div>
 		while (parent.name !== name) {
 			if (parent.type !== 'Element') {
-				if (parser.last_auto_closed_tag && parser.last_auto_closed_tag.tag === name) {
+				const message = parser.last_auto_closed_tag && parser.last_auto_closed_tag.tag === name
+					? `</${name}> attempted to close <${name}> that was already automatically closed by <${parser.last_auto_closed_tag.reason}>`
+					: `</${name}> attempted to close an element that was not open`;
 				parser.error({
 					code: `invalid-closing-tag`,
-						message: `<${parser.last_auto_closed_tag.tag}> cannot have child element <${parser.last_auto_closed_tag.reason}>`,
-					}, start);
-				}
-
-				parser.error({
-					code: `invalid-closing-tag`,
-					message: `</${name}> attempted to close an element that was not open`
+					message
 				}, start);
 			}
 
@@ -164,7 +160,7 @@ export default function tag(parser: Parser) {
 	} else if (closing_tag_omitted(parent.name, name)) {
 		parent.end = start;
 		parser.stack.pop();
-		parser.last_auto_closed_tag ={
+		parser.last_auto_closed_tag = {
 			tag: parent.name,
 			reason: name,
 			depth: parser.stack.length,

test/parser/samples/error-unmatched-closing-tag-autoclose/error.json

@@ -1,6 +1,6 @@
 {
 	"code": "invalid-closing-tag",
-	"message": "<p> cannot have child element <pre>",
+	"message": "</p> attempted to close <p> that was already automatically closed by <pre>",
 	"pos": 24,
 	"start": {
 		"character": 24,