Support unmapped areas in source maps.

pkg/source_maps/test/parser_test.dart

Index: pkg/source_maps/test/parser_test.dart
diff --git a/pkg/source_maps/test/parser_test.dart b/pkg/source_maps/test/parser_test.dart
index c99acb2f10ac4eba95a86a1001a0cac144b3744d..afdd7fb2c0396a2ebb0c1943cb501ea7fe7a6f27 100644
--- a/pkg/source_maps/test/parser_test.dart
+++ b/pkg/source_maps/test/parser_test.dart
@@ -9,6 +9,33 @@ import 'package:unittest/unittest.dart';
 import 'package:source_maps/source_maps.dart';
 import 'common.dart';
 
+const Map<String, dynamic> MAP_WITH_NO_SOURCE_LOCATION = const {
+    'version': 3,
+    'sourceRoot': '',
+    'sources': const ['input.dart'],
+    'names': const [],
+    'mappings': 'A',
+    'file': 'output.dart'
+};
+
+const Map<String, dynamic> MAP_WITH_SOURCE_LOCATION = const {
+    'version': 3,
+    'sourceRoot': '',
+    'sources': const ['input.dart'],
+    'names': const [],
+    'mappings': 'AAAA',
+    'file': 'output.dart'
+};
+
+const Map<String, dynamic> MAP_WITH_SOURCE_LOCATION_AND_NAME = const {
+    'version': 3,
+    'sourceRoot': '',
+    'sources': const ['input.dart'],
+    'names': const ['var'],
+    'mappings': 'AAAAA',
+    'file': 'output.dart'
+};
+
 main() {
   test('parse', () {
     var mapping = parseJson(EXPECTED_MAP);
@@ -33,4 +60,43 @@ main() {
     check(outputFunction, mapping, inputFunction, true);
     check(outputExpr, mapping, inputExpr, true);
   });
+
+  test('parse with no source location', () {
+    SingleMapping map = parse(JSON.encode(MAP_WITH_NO_SOURCE_LOCATION));
+    expect(map.lines.length, 1);
+    expect(map.lines.first.entries.length, 1);
+    TargetEntry entry = map.lines.first.entries.first;
+
+    expect(entry.column, 0);
+    expect(entry.sourceUrlId, null);
+    expect(entry.sourceColumn, null);
+    expect(entry.sourceLine, null);
+    expect(entry.sourceNameId, null);
+  });
+
+  test('parse with source location and no name', () {
+    SingleMapping map = parse(JSON.encode(MAP_WITH_SOURCE_LOCATION));
+    expect(map.lines.length, 1);
+    expect(map.lines.first.entries.length, 1);
+    TargetEntry entry = map.lines.first.entries.first;
+
+    expect(entry.column, 0);
+    expect(entry.sourceUrlId, 0);
+    expect(entry.sourceColumn, 0);
+    expect(entry.sourceLine, 0);
+    expect(entry.sourceNameId, null);
+  });
+
+  test('parse with source location and name', () {
+    SingleMapping map = parse(JSON.encode(MAP_WITH_SOURCE_LOCATION_AND_NAME));
+    expect(map.lines.length, 1);
+    expect(map.lines.first.entries.length, 1);
+    TargetEntry entry = map.lines.first.entries.first;
+
+    expect(entry.sourceUrlId, 0);
+    expect(entry.sourceUrlId, 0);
+    expect(entry.sourceColumn, 0);
+    expect(entry.sourceLine, 0);
+    expect(entry.sourceNameId, 0);
+  });
 }