Support user context

lib/sentry.dart

@@ -143,6 +143,13 @@ class SentryClient {
   /// Attached to the event payload.
   final String projectId;
 
+  @visibleForTesting
+  User _userContext;
+
+  set userContext(User val) {
+    _userContext = val;
+  }
+
   @visibleForTesting
   String get postUri =>
       '${dsnUri.scheme}://${dsnUri.host}/api/$projectId/store/';
@@ -170,6 +177,10 @@ class SentryClient {
     if (environmentAttributes != null)
       mergeAttributes(environmentAttributes.toJson(), into: data);
 
+    // merge the user context
+    if (_userContext != null) {
+      mergeAttributes({'user': _userContext.toJson()}, into: data);
+    }
     mergeAttributes(event.toJson(), into: data);
 
     List<int> body = utf8.encode(json.encode(data));
@@ -285,6 +296,7 @@ class Event {
     this.tags,
     this.extra,
     this.fingerprint,
+    this.userContext,
   });
 
   /// The logger that logged the event.
@@ -330,6 +342,8 @@ class Event {
   /// they must be JSON-serializable.
   final Map<String, dynamic> extra;
 
+  final User userContext;
+
   /// Used to deduplicate events by grouping ones with the same fingerprint
   /// together.
   ///
@@ -389,9 +403,45 @@ class Event {
 
     if (extra != null && extra.isNotEmpty) json['extra'] = extra;
 
+    Map<String, String> userContextMap;
+    if (userContext != null &&
+        (userContextMap = userContext.toJson()).isNotEmpty)
+      json['user'] = userContextMap;
+
     if (fingerprint != null && fingerprint.isNotEmpty)
       json['fingerprint'] = fingerprint;
 
     return json;
   }
 }
+
+/// Conforms to the User Interface contract for Sentry
+/// https://docs.sentry.io/clientdev/interfaces/user/
+///
+/// "user": {
+///  "id": "unique_id",
+///  "username": "my_user",
+///  "email": "[email protected]",
+///  "ip_address": "127.0.0.1",
+///  "subscription": "basic"
+///}
+///
+class User {
+  final String id;
+  final String username;
+  final String email;
+  final String ipAddress;
+  final String subscription;
+
+  const User(this.id, this.username, this.email, this.ipAddress, this.subscription);
+
+  Map<String, String> toJson() {
+    return <String, String>{
+      "id": id,
+      "username": username,
+      "email": email,
+      "ip_address": ipAddress,
+      "subscription": subscription
+    };
+  }
+}

test/sentry_test.dart

@@ -171,10 +171,71 @@ void main() {
 
       await client.close();
     });
+
+    test('$Event userContext overrides client', () async {
+      final MockClient httpMock = new MockClient();
+      final Clock fakeClock = new Clock.fixed(new DateTime(2017, 1, 2));
+
+      String loggedUserId; // used to find out what user context was sent
+      httpMock.answerWith((Invocation invocation) async {
+        if (invocation.memberName == #close) {
+          return null;
+        }
+        if (invocation.memberName == #post) {
+          // parse the body and detect which user context was sent
+          var bodyData = invocation.namedArguments[new Symbol("body")];
+          var decoded = new Utf8Codec().decode(bodyData);
+          var decodedJson = new JsonDecoder().convert(decoded);
+          loggedUserId = decodedJson['user']['id'];
+          return new Response('', 401, headers: <String, String>{
+            'x-sentry-error': 'Invalid api key',
+          });
+        }
+        fail('Unexpected invocation of ${invocation.memberName} in HttpMock');
+      });
+
+      const clientUserContext = const User(
+          "client_user", "username", "[email protected]", "127.0.0.1", "basic");
+      final eventUserContext = new User(
+          "event_user", "username", "[email protected]", "127.0.0.1", "basic");
+
+      final SentryClient client = new SentryClient(
+        dsn: _testDsn,
+        httpClient: httpMock,
+        clock: fakeClock,
+        uuidGenerator: () => 'X' * 32,
+        compressPayload: false,
+        environmentAttributes: const Event(
+          serverName: 'test.server.com',
+          release: '1.2.3',
+          environment: 'staging',
+        ),
+      );
+      client.userContext = clientUserContext;
+
+      try {
+        throw new ArgumentError('Test error');
+      } catch (error, stackTrace) {
+        final eventWithoutContext =
+            new Event(exception: error, stackTrace: stackTrace);
+        final eventWithContext = new Event(
+            exception: error,
+            stackTrace: stackTrace,
+            userContext: eventUserContext);
+        await client.capture(event: eventWithoutContext);
+        expect(loggedUserId, clientUserContext.id);
+        await client.capture(event: eventWithContext);
+        expect(loggedUserId, eventUserContext.id);
+      }
+
+      await client.close();
+    });
   });
 
   group('$Event', () {
     test('serializes to JSON', () {
+      final user = new User(
+          "user_id", "username", "[email protected]", "127.0.0.1", "basic");
       expect(
         new Event(
           message: 'test-message',
@@ -190,6 +251,7 @@ void main() {
             'g': 2,
           },
           fingerprint: <String>[Event.defaultFingerprint, 'foo'],
+          userContext: user,
         ).toJson(),
         <String, dynamic>{
           'platform': 'dart',
@@ -203,6 +265,13 @@ void main() {
           'tags': {'a': 'b', 'c': 'd'},
           'extra': {'e': 'f', 'g': 2},
           'fingerprint': ['{{ default }}', 'foo'],
+          'user': {
+            'id': 'user_id',
+            'username': 'username',
+            'email': '[email protected]',
+            'ip_address': '127.0.0.1',
+            'subscription': 'basic'
+          },
         },
       );
     });