fix: FlagsmithClient.close() doesn't kill polling manager properly (#133)

* Convert to daemon thread and ensure that closing works correctly * Remove unnecessary call to getEnvironmentFlags * Add comment * typo Co-authored-by: Kim Gustyr <kim.gustyr@flagsmith.com> --------- Co-authored-by: Kim Gustyr <kim.gustyr@flagsmith.com>

Author: matthewelwell

src/main/java/com/flagsmith/threads/PollingManager.java

@@ -32,7 +32,7 @@ public PollingManager(FlagsmithClient client, Integer interval) {
  * @return
  */
  private Thread initializeThread() {
- return new Thread() {
+ Thread thread = new Thread() {
  @Override
  public void run() {
  try {
@@ -45,6 +45,8 @@ public void run() {
  }
  }
  };
+ thread.setDaemon(true);
+ return thread;
  }
 
  /**
@@ -61,5 +63,10 @@ public void stopPolling() {
  internalThread.interrupt();
  }
 
-
+ /**
+ * Get thread status
+ */
+ public Boolean getIsThreadAlive() {
+ return internalThread.isAlive();
+ }
 }

src/test/java/com/flagsmith/FlagsmithClientTest.java

@@ -7,7 +7,6 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonNode;
-import com.flagsmith.responses.FlagsAndTraitsResponse;
 import com.flagsmith.config.FlagsmithCacheConfig;
 import com.flagsmith.config.FlagsmithConfig;
 import com.flagsmith.exceptions.FlagsmithApiError;
@@ -20,6 +19,7 @@
 import com.flagsmith.models.DefaultFlag;
 import com.flagsmith.models.Flags;
 import com.flagsmith.models.Segment;
+import com.flagsmith.responses.FlagsAndTraitsResponse;
 import com.flagsmith.threads.PollingManager;
 import com.flagsmith.threads.RequestProcessor;
 
@@ -591,4 +591,36 @@ public void testLocalEvaluation_ReturnsConsistentResults() throws FlagsmithClien
  Assert.assertEquals(flags.getFeatureValue("some_feature"), expectedValue);
  }
  }
+
+ @Test(groups = "unit")
+ public void testClose() throws FlagsmithApiError, InterruptedException {
+ // Given
+ int pollingInterval = 1;
+
+ FlagsmithConfig config = FlagsmithConfig
+ .newBuilder()
+ .withLocalEvaluation(true)
+ .withEnvironmentRefreshIntervalSeconds(pollingInterval)
+ .build();
+
+ FlagsmithApiWrapper mockedApiWrapper = mock(FlagsmithApiWrapper.class);
+ when(mockedApiWrapper.getEnvironment()).thenReturn(FlagsmithTestHelper.environmentModel());
+ when(mockedApiWrapper.getConfig()).thenReturn(config);
+
+ FlagsmithClient client = FlagsmithClient.newBuilder()
+ .withFlagsmithApiWrapper(mockedApiWrapper)
+ .withConfiguration(config)
+ .setApiKey("ser.dummy-key")
+ .build();
+
+ // When
+ client.close();
+
+ // Then
+ // Since the thread will only stop once it reads the interrupt signal correctly
+ // on its next polling interval, we need to wait for the polling interval
+ // to complete before checking the thread has been killed correctly.
+ Thread.sleep(pollingInterval);
+ Assert.assertFalse(client.getPollingManager().getIsThreadAlive());
+ }
 }