Handle new VM service message format (#364)

"Observatory listening on..." is eventually being updated to "Dart VM
Service listening on...". This change allows for parsing the VM service
URI from messages of either format.

See dart-lang/sdk#46756

Author: bkonyi

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.1-dev
+
+* Add support for scraping the service URI from the new Dart VM service message.
+
 ## 1.1.0 - 2022-1-18
 
 * Support function level coverage information, when running tests in the Dart

README.md

@@ -8,7 +8,7 @@ Dart.
 
 Tools
 -----
-`collect_coverage` collects coverage JSON from the Dart VM Observatory.
+`collect_coverage` collects coverage JSON from the Dart VM Service.
 `format_coverage` formats JSON coverage data into either
 [LCOV](http://ltp.sourceforge.net/coverage/lcov.php) or pretty-printed format.
 
@@ -33,7 +33,7 @@ or if the `pub global run` executables are on your PATH,
 collect_coverage --uri=http://... -o coverage.json --resume-isolates
 ```
 
-where `--uri` specifies the Observatory URI emitted by the VM.
+where `--uri` specifies the Dart VM Service URI emitted by the VM.
 
 If `collect_coverage` is invoked before the script from which coverage is to be
 collected, it will wait until it detects a VM observatory to which it can

lib/src/run_and_collect.dart

@@ -35,7 +35,7 @@ Future<Map<String, dynamic>> runAndCollect(String scriptPath,
       .transform(utf8.decoder)
       .transform(const LineSplitter())
       .listen((line) {
-    final uri = extractObservatoryUri(line);
+    final uri = extractVMServiceUri(line);
     if (uri != null) {
       serviceUriCompleter.complete(uri);
     }

lib/src/util.dart

@@ -38,20 +38,19 @@ Future<dynamic> retry(Future Function() f, Duration interval,
   }, duration: timeout);
 }
 
-/// Scrapes and returns the observatory URI from a string, or null if not found.
+/// Scrapes and returns the Dart VM service URI from a string, or null if not
+/// found.
 ///
 /// Potentially useful as a means to extract it from log statements.
-Uri? extractObservatoryUri(String str) {
-  const kObservatoryListening = 'Observatory listening on ';
-  final msgPos = str.indexOf(kObservatoryListening);
-  if (msgPos == -1) return null;
-  final startPos = msgPos + kObservatoryListening.length;
-  final endPos = str.indexOf(RegExp(r'(\s|$)'), startPos);
-  try {
-    return Uri.parse(str.substring(startPos, endPos));
-  } on FormatException {
-    return null;
+Uri? extractVMServiceUri(String str) {
+  final listeningMessageRegExp = RegExp(
+    r'(?:Observatory|Dart VM Service) listening on ((http|//)[a-zA-Z0-9:/=_\-\.\[\]]+)',
+  );
+  final match = listeningMessageRegExp.firstMatch(str);
+  if (match != null) {
+    return Uri.parse(match[1]!);
   }
+  return null;
 }
 
 /// Returns an open port by creating a temporary Socket

test/collect_coverage_api_test.dart

@@ -116,7 +116,7 @@ Future<Map<String, dynamic>> _collectCoverage(
       .transform(LineSplitter())
       .listen((line) {
     if (!serviceUriCompleter.isCompleted) {
-      final serviceUri = extractObservatoryUri(line);
+      final serviceUri = extractVMServiceUri(line);
       if (serviceUri != null) {
         serviceUriCompleter.complete(serviceUri);
       }

test/collect_coverage_test.dart

@@ -306,7 +306,7 @@ Future<String> _collectCoverage(bool functionCoverage) async {
       .transform(LineSplitter())
       .listen((line) {
     if (!serviceUriCompleter.isCompleted) {
-      final serviceUri = extractObservatoryUri(line);
+      final serviceUri = extractVMServiceUri(line);
       if (serviceUri != null) {
         serviceUriCompleter.complete(serviceUri);
       }

test/lcov_test.dart

@@ -221,7 +221,7 @@ Future<Map<String, HitMap>> _getHitMap() async {
       .transform(LineSplitter())
       .listen((line) {
     if (!serviceUriCompleter.isCompleted) {
-      final serviceUri = extractObservatoryUri(line);
+      final serviceUri = extractVMServiceUri(line);
       if (serviceUri != null) {
         serviceUriCompleter.complete(serviceUri);
       }

test/util_test.dart

@@ -96,37 +96,43 @@ void main() {
     });
   });
 
-  group('extractObservatoryUri', () {
+  group('extractVMServiceUri', () {
     test('returns null when not found', () {
-      expect(extractObservatoryUri('foo bar baz'), isNull);
+      expect(extractVMServiceUri('foo bar baz'), isNull);
     });
 
     test('returns null for an incorrectly formatted URI', () {
       const msg = 'Observatory listening on :://';
-      expect(extractObservatoryUri(msg), null);
+      expect(extractVMServiceUri(msg), null);
     });
 
     test('returns URI at end of string', () {
       const msg = 'Observatory listening on http://foo.bar:9999/';
-      expect(extractObservatoryUri(msg), Uri.parse('http://foo.bar:9999/'));
+      expect(extractVMServiceUri(msg), Uri.parse('http://foo.bar:9999/'));
     });
 
     test('returns URI with auth token at end of string', () {
       const msg = 'Observatory listening on http://foo.bar:9999/cG90YXRv/';
-      expect(extractObservatoryUri(msg),
-          Uri.parse('http://foo.bar:9999/cG90YXRv/'));
+      expect(
+          extractVMServiceUri(msg), Uri.parse('http://foo.bar:9999/cG90YXRv/'));
     });
 
     test('return URI embedded within string', () {
       const msg = '1985-10-26 Observatory listening on http://foo.bar:9999/ **';
-      expect(extractObservatoryUri(msg), Uri.parse('http://foo.bar:9999/'));
+      expect(extractVMServiceUri(msg), Uri.parse('http://foo.bar:9999/'));
     });
 
     test('return URI with auth token embedded within string', () {
       const msg =
           '1985-10-26 Observatory listening on http://foo.bar:9999/cG90YXRv/ **';
-      expect(extractObservatoryUri(msg),
-          Uri.parse('http://foo.bar:9999/cG90YXRv/'));
+      expect(
+          extractVMServiceUri(msg), Uri.parse('http://foo.bar:9999/cG90YXRv/'));
+    });
+
+    test('handles new Dart VM service message format', () {
+      const msg = 'Dart VM Service listening on http://foo.bar:9999/cG90YXRv/';
+      expect(
+          extractVMServiceUri(msg), Uri.parse('http://foo.bar:9999/cG90YXRv/'));
     });
   });