Reject invalid autolabel counters [#48]

lib/sequence-diagram.js

@@ -1612,6 +1612,7 @@ define('sequence/LabelPatternParser',[],() => {
 		let start = 1;
 		let inc = 1;
 		let dp = 0;
+
 		if(args[0]) {
 			start = Number(args[0]);
 			dp = Math.max(dp, countDP(args[0]));
@@ -1620,6 +1621,11 @@ define('sequence/LabelPatternParser',[],() => {
 			inc = Number(args[1]);
 			dp = Math.max(dp, countDP(args[1]));
 		}
+
+		if(Number.isNaN(start) || Number.isNaN(inc)) {
+			return null;
+		}
+
 		return {start, inc, dp};
 	}
 
@@ -1639,11 +1645,12 @@ define('sequence/LabelPatternParser',[],() => {
 			args = token.substr(p + 1).split(',');
 		}
 
+		let result = null;
 		if(type === 'inc') {
-			return parseCounter(args);
+			result = parseCounter(args);
 		}
 
-		return '<' + token + '>';
+		return result || ('<' + token + '>');
 	}
 
 	function parsePattern(raw) {

scripts/sequence/LabelPatternParser.js

@@ -16,6 +16,7 @@ define(() => {
 		let start = 1;
 		let inc = 1;
 		let dp = 0;
+
 		if(args[0]) {
 			start = Number(args[0]);
 			dp = Math.max(dp, countDP(args[0]));
@@ -24,6 +25,11 @@ define(() => {
 			inc = Number(args[1]);
 			dp = Math.max(dp, countDP(args[1]));
 		}
+
+		if(Number.isNaN(start) || Number.isNaN(inc)) {
+			return null;
+		}
+
 		return {start, inc, dp};
 	}
 
@@ -43,11 +49,12 @@ define(() => {
 			args = token.substr(p + 1).split(',');
 		}
 
+		let result = null;
 		if(type === 'inc') {
-			return parseCounter(args);
+			result = parseCounter(args);
 		}
 
-		return '<' + token + '>';
+		return result || ('<' + token + '>');
 	}
 
 	function parsePattern(raw) {

scripts/sequence/LabelPatternParser_spec.js

@@ -73,6 +73,15 @@ defineDescribe('Label Pattern Parser', ['./LabelPatternParser'], (parser) => {
 		]);
 	});
 
+	it('passes invalid counters through unchanged', () => {
+		expect(parser('<inc abc>')).toEqual([
+			'<inc abc>',
+		]);
+		expect(parser('<inc 1, abc>')).toEqual([
+			'<inc 1, abc>',
+		]);
+	});
+
 	it('assigns decimal places to counters by their written precision', () => {
 		const parsed = parser('<inc 5.0, 2.00><inc 2.00, 1.0>');
 		expect(parsed).toEqual([