fix: eventType should be required positional param

example/lib/event_form.dart

@@ -14,7 +14,7 @@ class _EventFormState extends State<EventForm> {
 
   void onPress() {
     AppState.of(context)
-      ..analytics.track(BaseEvent(eventType: _controller.text))
+      ..analytics.track(BaseEvent(_controller.text))
       ..setMessage('Event sent.');
   }
 

lib/amplitude.dart

@@ -51,7 +51,7 @@ class Amplitude {
   /// (whichever comes first), as well as on app close.
   ///
   /// ```
-  /// amplitude.track(BaseEvent(eventType: 'Button Clicked'))
+  /// amplitude.track(BaseEvent('Button Clicked'))
   /// ```
   Future<void> track(
     BaseEvent event, [

lib/events/base_event.dart

@@ -9,51 +9,51 @@ class BaseEvent extends EventOptions {
   Map<String, dynamic>? groups;
   Map<String, dynamic>? groupProperties;
 
-  BaseEvent({
-    String? userId,
-    String? deviceId,
-    int? timestamp,
-    int? eventId,
-    int? sessionId,
-    String? insertId,
-    double? locationLat,
-    double? locationLng,
-    String? appVersion,
-    String? versionName,
-    String? platform,
-    String? osName,
-    String? osVersion,
-    String? deviceBrand,
-    String? deviceManufacturer,
-    String? deviceModel,
-    String? carrier,
-    String? country,
-    String? region,
-    String? city,
-    String? dma,
-    String? idfa,
-    String? idfv,
-    String? adid,
-    String? appSetId,
-    String? androidId,
-    String? language,
-    String? library,
-    String? ip,
-    Plan? plan,
-    IngestionMetadata? ingestionMetadata,
-    double? revenue,
-    double? price,
-    int? quantity,
-    String? productId,
-    String? revenueType,
-    Map<String, dynamic>? extra,
-    String? partnerId,
-    required this.eventType,
-    this.eventProperties,
-    this.userProperties,
-    this.groups,
-    this.groupProperties,
-  }) : super(
+  BaseEvent(
+    this.eventType, {
+        String? userId,
+        String? deviceId,
+        int? timestamp,
+        int? eventId,
+        int? sessionId,
+        String? insertId,
+        double? locationLat,
+        double? locationLng,
+        String? appVersion,
+        String? versionName,
+        String? platform,
+        String? osName,
+        String? osVersion,
+        String? deviceBrand,
+        String? deviceManufacturer,
+        String? deviceModel,
+        String? carrier,
+        String? country,
+        String? region,
+        String? city,
+        String? dma,
+        String? idfa,
+        String? idfv,
+        String? adid,
+        String? appSetId,
+        String? androidId,
+        String? language,
+        String? library,
+        String? ip,
+        Plan? plan,
+        IngestionMetadata? ingestionMetadata,
+        double? revenue,
+        double? price,
+        int? quantity,
+        String? productId,
+        String? revenueType,
+        Map<String, dynamic>? extra,
+        String? partnerId,
+        this.eventProperties,
+        this.userProperties,
+        this.groups,
+        this.groupProperties,
+      }) : super(
           userId: userId,
           deviceId: deviceId,
           timestamp: timestamp,
@@ -131,7 +131,8 @@ class BaseEvent extends EventOptions {
       if (library != null) 'library': library,
       if (ip != null) 'ip': ip,
       if (plan != null) 'plan': plan?.toMap(),
-      if (ingestionMetadata != null) 'ingestion_metadata': ingestionMetadata?.toMap(),
+      if (ingestionMetadata != null)
+        'ingestion_metadata': ingestionMetadata?.toMap(),
       if (revenue != null) 'revenue': revenue,
       if (price != null) 'price': price,
       if (quantity != null) 'quantity': quantity,

lib/events/group_identify_event.dart

@@ -2,5 +2,5 @@ import '../constants.dart';
 import 'base_event.dart';
 
 class GroupIdentifyEvent extends BaseEvent {
-  GroupIdentifyEvent() : super(eventType: Constants.groupIdentifyEvent);
+  GroupIdentifyEvent() : super(Constants.groupIdentifyEvent);
 }

lib/events/identify_event.dart

@@ -2,5 +2,5 @@ import '../constants.dart';
 import 'base_event.dart';
 
 class IdentifyEvent extends BaseEvent {
-  IdentifyEvent() : super(eventType: Constants.identifyEvent);
+  IdentifyEvent() : super(Constants.identifyEvent);
 }

lib/events/revenue_event.dart

@@ -2,5 +2,5 @@ import '../constants.dart';
 import 'base_event.dart';
 
 class RevenueEvent extends BaseEvent {
-  RevenueEvent() : super(eventType: Constants.revenueEvent);
+  RevenueEvent() : super(Constants.revenueEvent);
 }

test/amplitude_test.dart

@@ -86,7 +86,7 @@ void main() {
     // Pass it for FlutterLibraryPlugin
     'library': '${Constants.packageName}/${Constants.packageVersion}'
   };
-  final testEvent = BaseEvent(eventType: 'testEvent');
+  final testEvent = BaseEvent('testEvent');
   final testEventMap = {
     'event_type': 'testEvent',
     'attempts': 0,

test/events/base_event_test.dart

@@ -8,7 +8,7 @@ void main() {
   group('BaseEvent', () {
     test('Should init with default values', () {
       final testEventType = 'test-event-type';
-      final event = BaseEvent(eventType: testEventType);
+      final event = BaseEvent(testEventType);
 
       expect(event.eventType, testEventType);
       expect(event.eventProperties, isNull);
@@ -30,7 +30,7 @@ void main() {
         'test-group-property-key': 'test-group-property-value'
       };
       final event = BaseEvent(
-        eventType: testEventType,
+        testEventType,
         eventProperties: testEventProperties,
         userProperties: testUserProperties,
         groups: testGroups,
@@ -86,6 +86,7 @@ void main() {
       final partnerId = 'partner_id';
 
       final event = BaseEvent(
+        eventType,
         userId: userId,
         deviceId: deviceId,
         timestamp: timestamp,
@@ -124,7 +125,6 @@ void main() {
         revenueType: revenueType,
         extra: extra,
         partnerId: partnerId,
-        eventType: eventType,
       );
 
       final expectedMap = {
@@ -179,7 +179,7 @@ void main() {
       final deviceId = 'device_id';
       final eventType = 'event_type';
 
-      final originalEvent = BaseEvent(userId: originalUserId, deviceId: deviceId, eventType: eventType);
+      final originalEvent = BaseEvent(eventType, userId: originalUserId, deviceId: deviceId);
       final newOptions = EventOptions(userId: newUserId);
 
       originalEvent.mergeEventOptions(newOptions);