add test for parseLine that can not resolve the filename or line/co…

…lumn numbers

index.js

@@ -209,10 +209,15 @@ StackUtils.prototype.parseLine = function parseLine(line) {
 	var col = match[10];
 	var native = match[11] === 'native';
 
-	var res = {
-		line: Number(lnum),
-		column: Number(col)
-	};
+	var res = {};
+
+	if (lnum) {
+		res.line = Number(lnum);
+	}
+
+	if (col) {
+		res.column = Number(col);
+	}
 
 	if (file) {
 		file = file.replace(/\\/g, '/');

test.js

@@ -158,7 +158,7 @@ test('at: with stackStart', t => {
 	const at = capture.redirect1('call', 'at', capture.call);
 
 	t.same(at, {
-		file: `fixtures${path.sep}capture-fixture.js`,
+		file: `fixtures/capture-fixture.js`,
 		line: 11,
 		column: 22,
 		type: 'CaptureFixture',
@@ -274,7 +274,7 @@ test('parseLine', t => {
 		evalOrigin: '<anonymous>',
 		evalLine: 57,
 		evalColumn: 9,
-		evalFile: path.join(fixtureDir, 'capture-fixture.js'),
+		evalFile: path.join(fixtureDir, 'capture-fixture.js').replace(/\\/g, '/'),
 		function: 'eval'
 	};
 
@@ -287,6 +287,13 @@ test('parseLine', t => {
 	t.same(actual, expected);
 });
 
+test('parseLine: handles native errors', t => {
+	t.same(StackUtils.parseLine('    at Error (native)'), {
+		native: true,
+		function: 'Error'
+	});
+});
+
 function join() {
 	var args = Array.prototype.slice.call(arguments);
 	return flatten(args).join('\n') + '\n';