Add a test for root_line with aboslute test path

Towards #2037

Add a test case running a file with an absolute path.

pkgs/test/test/runner/json_reporter_test.dart

@@ -512,7 +512,7 @@ void main() {
  args: ['-p', 'chrome']);
  }, tags: ['chrome'], skip: 'https://github.com/dart-lang/test/issues/872');
 
- test('the root suite if applicable', () {
+ test('the root suite from a relative path', () {
  return _expectReport(
  '''
  customTest('success 1', () {});
@@ -543,6 +543,43 @@ void main() {
  'common.dart': '''
 import 'package:test/test.dart';
 
+void customTest(String name, dynamic Function() testFn) => test(name, testFn);
+''',
+ });
+ });
+
+ test('the root suite from an absolute path', () {
+ return _expectReport(
+ '''
+ customTest('success 1', () {});
+ test('success 2', () {});
+ ''',
+ useRelativePath: false,
+ [
+ [
+ suiteJson(0),
+ testStartJson(1, 'loading test.dart', groupIDs: []),
+ testDoneJson(1, hidden: true),
+ ],
+ [
+ groupJson(2, testCount: 2),
+ testStartJson(3, 'success 1',
+ line: 3,
+ column: 60,
+ url: p.toUri(p.join(d.sandbox, 'common.dart')).toString(),
+ rootColumn: 7,
+ rootLine: 7,
+ rootUrl: p.toUri(p.join(d.sandbox, 'test.dart')).toString()),
+ testDoneJson(3),
+ testStartJson(4, 'success 2', line: 8, column: 7),
+ testDoneJson(4),
+ ]
+ ],
+ doneJson(),
+ externalLibraries: {
+ 'common.dart': '''
+import 'package:test/test.dart';
+
 void customTest(String name, dynamic Function() testFn) => test(name, testFn);
 ''',
  });
@@ -586,6 +623,7 @@ void customTest(String name, dynamic Function() testFn) => test(name, testFn);
 Future<void> _expectReport(String tests,
  List<List<Object /*Map|Matcher*/ >> expected, Map<Object, Object> done,
  {List<String> args = const [],
+ bool useRelativePath = true,
  Map<String, String> externalLibraries = const {}}) async {
  var testContent = StringBuffer('''
 import 'dart:async';
@@ -603,8 +641,9 @@ import 'package:test/test.dart';
  ..writeln('}');
 
  await d.file('test.dart', testContent.toString()).create();
+ var testPath = useRelativePath ? 'test.dart' : p.join(d.sandbox, 'test.dart');
 
- var test = await runTest(['test.dart', '--chain-stack-traces', ...args],
+ var test = await runTest([testPath, '--chain-stack-traces', ...args],
  reporter: 'json');
  await test.shouldExit();