Add configuration for setting custom HTTP headers for requests to the…

… collector (close #34)

android/src/main/kotlin/com/snowplowanalytics/snowplow_tracker/readers/configurations/NetworkConfigurationReader.kt

@@ -20,6 +20,7 @@ class NetworkConfigurationReader(values: Map<String, Any>) {
     val endpoint: String by values
     val method: String? by valuesDefault
     val customPostPath: String? by valuesDefault
+    val requestHeaders: Map<String, String>? by valuesDefault
 
     fun toConfiguration(): NetworkConfiguration {
         val networkConfig: NetworkConfiguration = if (method != null) {
@@ -31,6 +32,7 @@ class NetworkConfigurationReader(values: Map<String, Any>) {
             NetworkConfiguration(endpoint)
         }
         customPostPath?.let { networkConfig.customPostPath(it) }
+        requestHeaders?.let { networkConfig.requestHeaders(it) }
         return networkConfig
     }
 }

doc/02-configuration.md

@@ -22,6 +22,7 @@ The only required attributes of the `Snowplow.createTracker` method are `namespa
 | `endpoint` | `String`                | URI for the Snowplow collector endpoint.                                             |
 | `method` | `Method?`               | HTTP method to use: `Method.get` or `Method.post` (`Method.post` is default).        |
 | `customPostPath` | `String?`               | Custom POST path.                                                                    |
+| `requestHeaders` | `Map<String, String>?` | Map of custom HTTP headers to add to requests to the collector. |
 | `trackerConfig` | `TrackerConfiguration?` | Configuration of the tracker and the core tracker properties.                        |
 | `gdprConfig` | `GdprConfiguration?`    | Determines the GDPR context that will be attached to all events sent by the tracker. |
 | `subjectConfig` | `SubjectConfiguration?` | Subject information about tracked user and device that is added to events.           |

example/integration_test/configuration_test.dart

@@ -246,4 +246,21 @@ void main() {
       return true;
     });
   });
+
+  testWidgets("sets custom request headers", (WidgetTester tester) async {
+    SnowplowTracker tracker = await Snowplow.createTracker(
+        namespace: 'custom-headers',
+        endpoint: SnowplowTests.microEndpoint,
+        requestHeaders: {'Warning': 'works'});
+
+    await tracker
+        .track(const Structured(category: 'category', action: 'action'));
+
+    expect(
+        await SnowplowTests.checkMicroGood((events) =>
+            (events.length == 1) &&
+            (events[0]['rawEvent']['context']['headers']
+                .contains('Warning: works'))),
+        isTrue);
+  });
 }

ios/Classes/readers/configurations/NetworkConfigurationReader.swift

@@ -16,6 +16,7 @@ struct NetworkConfigurationReader: Decodable {
     let endpoint: String
     let method: String?
     let customPostPath: String?
+    let requestHeaders: [String: String]?
 }
 
 extension NetworkConfigurationReader {
@@ -31,6 +32,9 @@ extension NetworkConfigurationReader {
         if let c = customPostPath {
             networkConfig.customPostPath(c)
         }
+        if let h = requestHeaders {
+            networkConfig.requestHeaders(h)
+        }
         return networkConfig
     }
 }

lib/configurations/network_configuration.dart

@@ -26,16 +26,23 @@ class NetworkConfiguration {
   /// You will need to configure your collector to accept your custom path.
   final String? customPostPath;
 
+  /// Custom HTTP headers to add to HTTP requests to the collector.
+  final Map<String, String>? requestHeaders;
+
   const NetworkConfiguration(
-      {required this.endpoint, this.method, this.customPostPath});
+      {required this.endpoint,
+      this.method,
+      this.customPostPath,
+      this.requestHeaders});
 
   Map<String, Object?> toMap() {
     final conf = <String, Object?>{
       'endpoint': endpoint,
       'method': method?.name,
       'customPostPath': customPostPath?[0] == '/'
           ? customPostPath?.substring(1)
-          : customPostPath
+          : customPostPath,
+      'requestHeaders': requestHeaders
     };
     conf.removeWhere((key, value) => value == null);
     return conf;

lib/snowplow.dart

@@ -34,19 +34,24 @@ class Snowplow {
   /// [endpoint] refers to the Snowplow collector endpoint.
   /// [method] is the HTTP method used to send events to collector and it defaults to POST.
   /// [customPostPath] is an optional string for custom POST collector paths.
+  /// [requestHeaders] is an optional map of custom HTTP headers to add to requests to the collector.
   static Future<SnowplowTracker> createTracker(
       {required String namespace,
       required String endpoint,
       Method? method,
       String? customPostPath,
+      Map<String, String>? requestHeaders,
       TrackerConfiguration? trackerConfig,
       SubjectConfiguration? subjectConfig,
       GdprConfiguration? gdprConfig,
       EmitterConfiguration? emitterConfig}) async {
     final configuration = Configuration(
         namespace: namespace,
         networkConfig: NetworkConfiguration(
-            endpoint: endpoint, method: method, customPostPath: customPostPath),
+            endpoint: endpoint,
+            method: method,
+            customPostPath: customPostPath,
+            requestHeaders: requestHeaders),
         trackerConfig: trackerConfig,
         subjectConfig: subjectConfig,
         gdprConfig: gdprConfig,

lib/src/web/readers/configurations/network_configuration_reader.dart

@@ -18,7 +18,10 @@ class NetworkConfigurationReader extends NetworkConfiguration {
             method: map['method'] == null
                 ? null
                 : Method.values.byName(map['method']),
-            customPostPath: map['customPostPath']);
+            customPostPath: map['customPostPath'],
+            requestHeaders: map['requestHeaders'] == null
+                ? null
+                : (map['requestHeaders'] as Map<Object?, Object?>).cast());
 
   void addTrackerOptions(dynamic options) {
     if (method != null) {
@@ -27,5 +30,8 @@ class NetworkConfigurationReader extends NetworkConfiguration {
     if (customPostPath != null) {
       options['postPath'] = '/$customPostPath';
     }
+    if (requestHeaders != null) {
+      options['customHeaders'] = requestHeaders;
+    }
   }
 }

test/snowplow_test.dart

@@ -122,6 +122,23 @@ void main() {
         }));
   });
 
+  test('createsTrackerWithCustomRequestHeaders', () async {
+    await Snowplow.createTracker(
+        namespace: 'tns1',
+        endpoint: 'https://snowplowanalytics.com',
+        requestHeaders: {'header1': 'value1', 'header2': 'value2'});
+
+    expect(
+        methodCall,
+        isMethodCall('createTracker', arguments: {
+          'namespace': 'tns1',
+          'networkConfig': {
+            'endpoint': 'https://snowplowanalytics.com',
+            'requestHeaders': {'header1': 'value1', 'header2': 'value2'}
+          }
+        }));
+  });
+
   test('createsTrackerWithEmitterConfig', () async {
     await Snowplow.createTracker(
         namespace: 'tns1',