feat: Prevent excessive fetch calls

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.6.0
+
+* Feat: save network calls when context fields don't change
+
 ## 1.5.3
 
 * Fix: payload stringify in bootstrap

README.md

@@ -30,6 +30,7 @@ final unleash = UnleashClient(
     url: Uri.parse('https://<your-unleash-instance>/api/frontend'),
     clientKey: '<your-client-side-token>',
     appName: 'my-app');
+unleash.start();
 ```
 
 #### Connection options

lib/unleash_context.dart

@@ -29,4 +29,32 @@ class UnleashContext {
 
     return params;
   }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    if (other is! UnleashContext) return false;
+    return other.userId == userId &&
+        other.sessionId == sessionId &&
+        other.remoteAddress == remoteAddress &&
+        _mapEquals(other.properties, properties);
+  }
+
+  @override
+  int get hashCode {
+    return Object.hash(
+      userId,
+      sessionId,
+      remoteAddress,
+      properties,
+    );
+  }
+
+  static bool _mapEquals(Map<String, String> map1, Map<String, String> map2) {
+    if (map1.length != map2.length) return false;
+    for (final key in map1.keys) {
+      if (map1[key] != map2[key]) return false;
+    }
+    return true;
+  }
 }

lib/unleash_proxy_client_flutter.dart

@@ -257,7 +257,27 @@ class UnleashClient extends EventEmitter {
     }
   }
 
+  /// Checks if any of the provided context fields are different from the current ones.
+  bool _anyFieldHasChanged(Map<String, String> fields) {
+    for (var entry in fields.entries) {
+      String key = entry.key;
+      String newValue = entry.value;
+
+      if (key == 'userId') {
+        if (context.userId != newValue) return true;
+      } else if (key == 'sessionId') {
+        if (context.sessionId != newValue) return true;
+      } else if (key == 'remoteAddress') {
+        if (context.remoteAddress != newValue) return true;
+      } else {
+        if (context.properties[key] != newValue) return true;
+      }
+    }
+    return false;
+  }
+
   Future<void> updateContext(UnleashContext unleashContext) async {
+    if (unleashContext == context) return;
     if (started == false) {
       await _waitForEvent('initialized');
       _updateContextFields(unleashContext);
@@ -286,6 +306,7 @@ class UnleashClient extends EventEmitter {
   }
 
   Future<void> setContextFields(Map<String, String> fields) async {
+    if (!_anyFieldHasChanged(fields)) return;
     if (clientState == ClientState.ready) {
       fields.forEach((field, value) {
         _updateContextField(field, value);

pubspec.yaml

@@ -3,7 +3,7 @@ description: A Flutter/Dart client that can be used together with the unleash-pr
 homepage: https://github.com/Unleash/unleash_proxy_client_flutter
 repository: https://github.com/Unleash/unleash_proxy_client_flutter
 issue_tracker: https://github.com/Unleash/unleash_proxy_client_flutter
-version: 1.5.3
+version: 1.6.0
 
 environment:
   sdk: ">=2.18.0 <4.0.0"

test/unleash_proxy_client_flutter_test.dart

@@ -588,6 +588,100 @@ void main() {
     ]);
   });
 
+  test(
+      'set and update context with the same value will not trigger new fetch call',
+      () async {
+    final getMock = GetMock();
+    final unleash = UnleashClient(
+        url: url,
+        clientKey: 'proxy-123',
+        appName: 'flutter-test',
+        sessionIdGenerator: generateSessionId,
+        storageProvider: InMemoryStorageProvider(),
+        fetcher: getMock);
+    await unleash.updateContext(UnleashContext(
+        userId: '123',
+        remoteAddress: 'address',
+        sessionId: 'session',
+        properties: {'customKey': 'customValue'}));
+    // update whole context before start but keep data identical
+    await unleash.updateContext(UnleashContext(
+        userId: '123',
+        remoteAddress: 'address',
+        sessionId: 'session',
+        properties: {'customKey': 'customValue'}));
+    // set standard property before start
+    unleash.setContextField('userId', '123');
+    // set standard an custom property before start
+    unleash.setContextFields({'customKey': 'customValue', 'userId': '123'});
+    await unleash.start();
+
+    // set standard properties after start
+    await unleash.setContextField('userId', '123');
+    await unleash.setContextField('remoteAddress', 'address');
+    await unleash.setContextField('sessionId', 'session');
+    // set custom property after start
+    await unleash.setContextField('customKey', 'customValue');
+    // set standard and custom property after start
+    await unleash
+        .setContextFields({'customKey': 'customValue', 'userId': '123'});
+    // update whole context after start
+    await unleash.updateContext(UnleashContext(
+        userId: '123',
+        remoteAddress: 'address',
+        sessionId: 'session',
+        properties: {'customKey': 'customValue'}));
+
+    expect(getMock.calledTimes, 1);
+    expect(getMock.calledWithUrls, [
+      Uri.parse(
+          'https://app.unleash-hosted.com/demo/api/proxy?userId=123&remoteAddress=address&sessionId=session&properties%5BcustomKey%5D=customValue&appName=flutter-test&environment=default')
+    ]);
+  });
+
+  test('update context removing fields triggers new flag update', () async {
+    final getMock = GetMock();
+    final unleash = UnleashClient(
+        url: url,
+        clientKey: 'proxy-123',
+        appName: 'flutter-test',
+        sessionIdGenerator: generateSessionId,
+        storageProvider: InMemoryStorageProvider(),
+        fetcher: getMock);
+    // ignore this one
+    unleash.updateContext(UnleashContext(
+        userId: '123',
+        remoteAddress: 'address',
+        sessionId: 'session',
+        properties: {
+          'customKey': 'customValue',
+          'remove1': 'val1',
+          'remove2': 'val2'
+        }));
+    // first call
+    unleash.updateContext(UnleashContext(
+        userId: '123',
+        remoteAddress: 'address',
+        sessionId: 'session',
+        properties: {'customKey': 'customValue', 'remove1': 'val1'}));
+    await unleash.start();
+
+    // remove another field and second call
+    await unleash.updateContext(UnleashContext(
+        userId: '123',
+        remoteAddress: 'address',
+        sessionId: 'session',
+        properties: {'customKey': 'customValue'}));
+
+    expect(getMock.calledTimes, 2);
+    expect(getMock.calledWithUrls, [
+      Uri.parse(
+          'https://app.unleash-hosted.com/demo/api/proxy?userId=123&remoteAddress=address&sessionId=session&properties%5BcustomKey%5D=customValue&properties%5Bremove1%5D=val1&appName=flutter-test&environment=default'),
+      Uri.parse(
+          'https://app.unleash-hosted.com/demo/api/proxy?userId=123&remoteAddress=address&sessionId=session&properties%5BcustomKey%5D=customValue&appName=flutter-test&environment=default')
+    ]);
+  });
+
   test('update context without await', () async {
     final getMock = GetMock();
     final unleash = UnleashClient(