feat: backup file on streaming (#323)

Author: kwasniew

.github/workflows/pull_requests.yml

@@ -21,6 +21,7 @@ jobs:
       - name: Build, test, coverage
         run: ./mvnw clean test jacoco:report
       - name: Coveralls parallel
+        if: matrix.os != 'macos'
         uses: coverallsapp/github-action@v2
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}

pom.xml

@@ -58,7 +58,7 @@
         <dependency>
             <groupId>io.getunleash</groupId>
             <artifactId>yggdrasil-engine</artifactId>
-            <version>0.3.2</version>
+            <version>0.4.2</version>
         </dependency>
         <dependency>
             <groupId>com.google.code.gson</groupId>

src/main/java/io/getunleash/repository/FeatureRepositoryImpl.java

@@ -237,10 +237,12 @@ public Stream<FeatureDefinition> listKnownToggles() {
         return this.engine.listKnownToggles().stream().map(FeatureDefinition::new);
     }
 
-    private synchronized void handleStreamingUpdate(String data) {
+    synchronized void handleStreamingUpdate(String data) {
         try {
             engine.takeState(data);
-            // TODO: write backup when engine exposes current state
+
+            String currentState = engine.getState();
+            featureBackupHandler.write(currentState);
 
             ClientFeaturesResponse response = ClientFeaturesResponse.updated(data);
             eventDispatcher.dispatch(response);

src/test/java/io/getunleash/repository/FeatureRepositoryTest.java

@@ -468,6 +468,50 @@ public void server_errors_should_incrementally_increase_interval()
         assertThat(featureRepository.getFailures()).isEqualTo(0);
     }
 
+    @Test
+    public void should_write_backup_file_when_streaming_update_received() throws Exception {
+        UnleashConfig streamingConfig =
+                UnleashConfig.builder()
+                        .appName("streaming-test")
+                        .unleashAPI("http://localhost:4242/api/")
+                        .scheduledExecutor(mock(UnleashScheduledExecutor.class))
+                        .disableMetrics()
+                        .disablePolling()
+                        .experimentalStreamingMode()
+                        .build();
+
+        when(backupHandler.read()).thenReturn(Optional.empty());
+
+        FeatureRepositoryImpl repository =
+                new FeatureRepositoryImpl(
+                        streamingConfig,
+                        backupHandler,
+                        new UnleashEngine(),
+                        fetcher,
+                        streamingFetcher,
+                        bootstrapHandler);
+
+        String streamingData =
+                "{\"events\":[{\"type\":\"hydration\",\"eventId\":1,\"features\":[{\"name\":\"testFeature\",\"enabled\":true,\"strategies\":[],\"variants\":[]}],\"segments\":[]}]}";
+
+        repository.handleStreamingUpdate(streamingData);
+
+        ArgumentCaptor<String> backupContentCaptor = ArgumentCaptor.forClass(String.class);
+        verify(backupHandler, times(1)).write(backupContentCaptor.capture());
+
+        String savedBackupContent = backupContentCaptor.getValue();
+
+        assertThat(savedBackupContent).contains("\"features\"");
+        assertThat(savedBackupContent).contains("\"segments\"");
+
+        assertThat(savedBackupContent).contains("\"testFeature\"");
+
+        assertThat(savedBackupContent).contains("\"version\":2");
+        assertThat(savedBackupContent).contains("\"query\":");
+
+        assertThat(savedBackupContent).doesNotContain("\"events\""); // store state not events
+    }
+
     private class TestRunner {
 
         private final UnleashScheduledExecutor executor;