Make EdgeDBClient implement AutoCloseable

src/driver/src/main/java/com/edgedb/driver/EdgeDBClient.java

@@ -31,7 +31,7 @@
 /**
  * Represents a client pool used to interact with EdgeDB.
  */
-public final class EdgeDBClient implements StatefulClient, EdgeDBQueryable {
+public final class EdgeDBClient implements StatefulClient, EdgeDBQueryable, AutoCloseable {
     private static final Logger logger = LoggerFactory.getLogger(EdgeDBClient.class);
 
     private static final class PooledClient {
@@ -115,6 +115,10 @@ private EdgeDBClient(@NotNull EdgeDBClient other, Session session) {
         this.clientAvailability = other.clientAvailability;
     }
 
+    public int getClientCount() {
+        return this.clientCount.get();
+    }
+
     private @NotNull ClientFactory createClientFactory() throws ConfigurationException {
         if(config.getClientType() == ClientType.TCP) {
             return EdgeDBTCPClient::new;
@@ -321,6 +325,15 @@ public CompletionStage<List<Json>> queryJsonElements(@NotNull String query, @Nul
         );
     }
 
+    @Override
+    public void close() throws Exception {
+        int count = clientCount.get();
+        while(!clients.isEmpty() && count > 0) {
+            clients.poll().client.disconnect().toCompletableFuture().get();
+            count = clientCount.decrementAndGet();
+        }
+    }
+
     private synchronized CompletionStage<BaseEdgeDBClient> getClient() {
         logger.trace("polling cached clients...");
         var cachedClient = clients.poll();

src/driver/src/test/java/ClientTests.java

@@ -0,0 +1,29 @@
+import com.edgedb.driver.EdgeDBClient;
+import com.edgedb.driver.exceptions.EdgeDBException;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ClientTests {
+    @Test
+    public void testAutoClose() throws Exception {
+        EdgeDBClient client;
+        try {
+            client = new EdgeDBClient();
+        } catch (IOException | EdgeDBException e) {
+            throw new RuntimeException(e);
+        }
+
+        var result = client.querySingle(String.class, "SELECT 'Hello, Java'")
+                        .toCompletableFuture().get();
+
+        assertThat(result).isEqualTo("Hello, Java");
+        assertThat(client.getClientCount()).isEqualTo(1);
+
+        client.close();
+
+        assertThat(client.getClientCount()).isEqualTo(0);
+    }
+}