Java: Added Hexists command for BaseClient and BaseTransaction (Hash …

…Commands) (valkey-io#1016)

* Java: Added Hexists command for BaseClient and BaseTransaction (Hash Commands)

* Added examples to documentation.

* Minor fixes based on PR review.

* Minor updates based on PR comments.

* Minor update to TransactionTestUtilities.

java/client/src/main/java/glide/api/BaseClient.java

@@ -10,6 +10,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.Exists;
 import static redis_request.RedisRequestOuterClass.RequestType.GetString;
 import static redis_request.RedisRequestOuterClass.RequestType.HashDel;
+import static redis_request.RedisRequestOuterClass.RequestType.HashExists;
 import static redis_request.RedisRequestOuterClass.RequestType.HashGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashMGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashSet;
@@ -174,6 +175,10 @@ protected String handleStringOrNullResponse(Response response) throws RedisExcep
         return handleRedisResponse(String.class, true, response);
     }
 
+    protected Boolean handleBooleanResponse(Response response) throws RedisException {
+        return handleRedisResponse(Boolean.class, false, response);
+    }
+
     protected Long handleLongResponse(Response response) throws RedisException {
         return handleRedisResponse(Long.class, false, response);
     }
@@ -305,6 +310,12 @@ public CompletableFuture<String[]> hmget(@NonNull String key, @NonNull String[]
                 HashMGet, arguments, response -> castArray(handleArrayResponse(response), String.class));
     }
 
+    @Override
+    public CompletableFuture<Boolean> hexists(@NonNull String key, @NonNull String field) {
+        return commandManager.submitNewCommand(
+                HashExists, new String[] {key, field}, this::handleBooleanResponse);
+    }
+
     @Override
     public CompletableFuture<Long> sadd(String key, String[] members) {
         String[] arguments = ArrayUtils.addFirst(members, key);

java/client/src/main/java/glide/api/commands/HashCommands.java

@@ -64,4 +64,22 @@ public interface HashCommands {
      * </pre>
      */
     CompletableFuture<String[]> hmget(String key, String[] fields);
+
+    /**
+     * Returns if <code>field</code> is an existing field in the hash stored at <code>key</code>.
+     *
+     * @see <a href="https://redis.io/commands/hexists/">redis.io</a> for details.
+     * @param key The key of the hash.
+     * @param field The field to check in the hash stored at <code>key</code>.
+     * @return <code>True</code> if the hash contains the specified field. If the hash does not
+     *     contain the field, or if the key does not exist, it returns <code>False</code>.
+     * @example
+     *     <pre>
+     * Boolean exists = client.hexists("my_hash", "field1").get()
+     * assert exists
+     * Boolean exists = client.hexists("my_hash", "non_existent_field").get()
+     * assert !exists
+     * </pre>
+     */
+    CompletableFuture<Boolean> hexists(String key, String field);
 }

java/client/src/main/java/glide/api/models/BaseTransaction.java

@@ -9,6 +9,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.Exists;
 import static redis_request.RedisRequestOuterClass.RequestType.GetString;
 import static redis_request.RedisRequestOuterClass.RequestType.HashDel;
+import static redis_request.RedisRequestOuterClass.RequestType.HashExists;
 import static redis_request.RedisRequestOuterClass.RequestType.HashGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashMGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashSet;
@@ -382,6 +383,23 @@ public T hmget(@NonNull String key, @NonNull String[] fields) {
         return getThis();
     }
 
+    /**
+     * Returns if <code>field</code> is an existing field in the hash stored at <code>key</code>.
+     *
+     * @see <a href="https://redis.io/commands/hexists/">redis.io</a> for details.
+     * @param key The key of the hash.
+     * @param field The field to check in the hash stored at <code>key</code>.
+     * @return Command Response - <code>True</code> if the hash contains the specified field. If the
+     *     hash does not contain the field, or if the key does not exist, it returns <code>False
+     *     </code>.
+     */
+    public T hexists(@NonNull String key, @NonNull String field) {
+        ArgsArray commandArgs = buildArgs(key, field);
+
+        protobufTransaction.addCommands(buildCommand(HashExists, commandArgs));
+        return getThis();
+    }
+
     /**
      * Add specified members to the set stored at <code>key</code>. Specified members that are already
      * a member of this set are ignored.

java/client/src/test/java/glide/api/RedisClientTest.java

@@ -19,6 +19,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.Exists;
 import static redis_request.RedisRequestOuterClass.RequestType.GetString;
 import static redis_request.RedisRequestOuterClass.RequestType.HashDel;
+import static redis_request.RedisRequestOuterClass.RequestType.HashExists;
 import static redis_request.RedisRequestOuterClass.RequestType.HashGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashMGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashSet;
@@ -594,6 +595,31 @@ public void hmget_success() {
         assertEquals(value, payload);
     }
 
+    @SneakyThrows
+    @Test
+    public void hexists_success() {
+        // setup
+        String key = "testKey";
+        String field = "testField";
+        String[] args = new String[] {key, field};
+        Boolean value = true;
+
+        CompletableFuture<Boolean> testResponse = mock(CompletableFuture.class);
+        when(testResponse.get()).thenReturn(value);
+
+        // match on protobuf request
+        when(commandManager.<Boolean>submitNewCommand(eq(HashExists), eq(args), any()))
+                .thenReturn(testResponse);
+
+        // exercise
+        CompletableFuture<Boolean> response = service.hexists(key, field);
+        Boolean payload = response.get();
+
+        // verify
+        assertEquals(testResponse, response);
+        assertEquals(value, payload);
+    }
+
     @SneakyThrows
     @Test
     public void sadd_returns_success() {

java/client/src/test/java/glide/api/models/TransactionTests.java

@@ -9,6 +9,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.Exists;
 import static redis_request.RedisRequestOuterClass.RequestType.GetString;
 import static redis_request.RedisRequestOuterClass.RequestType.HashDel;
+import static redis_request.RedisRequestOuterClass.RequestType.HashExists;
 import static redis_request.RedisRequestOuterClass.RequestType.HashGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashMGet;
 import static redis_request.RedisRequestOuterClass.RequestType.HashSet;
@@ -122,6 +123,10 @@ public void transaction_builds_protobuf_request(BaseTransaction<?> transaction)
         transaction.hdel("key", new String[] {"field"});
         results.add(Pair.of(HashDel, ArgsArray.newBuilder().addArgs("key").addArgs("field").build()));
 
+        transaction.hexists("key", "field");
+        results.add(
+                Pair.of(HashExists, ArgsArray.newBuilder().addArgs("key").addArgs("field").build()));
+
         transaction.sadd("key", new String[] {"value"});
         results.add(Pair.of(SAdd, ArgsArray.newBuilder().addArgs("key").addArgs("value").build()));
 

java/integTest/src/test/java/glide/SharedCommandTests.java

@@ -10,6 +10,7 @@
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -444,6 +445,21 @@ public void hmget_multiple_existing_fields_non_existing_field_non_existing_key(
                 client.hmget("non_existing_key", new String[] {field1, field2}).get());
     }
 
+    @SneakyThrows
+    @ParameterizedTest
+    @MethodSource("getClients")
+    public void hexists_existing_field_non_existing_field_non_existing_key(BaseClient client) {
+        String key = UUID.randomUUID().toString();
+        String field1 = UUID.randomUUID().toString();
+        String field2 = UUID.randomUUID().toString();
+        Map<String, String> fieldValueMap = Map.of(field1, "value1", field2, "value1");
+
+        assertEquals(2, client.hset(key, fieldValueMap).get());
+        assertTrue(client.hexists(key, field1).get());
+        assertFalse(client.hexists(key, "non_existing_field").get());
+        assertFalse(client.hexists("non_existing_key", field2).get());
+    }
+
     @SneakyThrows
     @ParameterizedTest
     @MethodSource("getClients")

java/integTest/src/test/java/glide/TransactionTestUtilities.java

@@ -44,6 +44,7 @@ public static BaseTransaction<?> transactionTest(BaseTransaction<?> baseTransact
 
         baseTransaction.hset(key4, Map.of(field1, value1, field2, value2));
         baseTransaction.hget(key4, field1);
+        baseTransaction.hexists(key4, field2);
         baseTransaction.hmget(key4, new String[] {field1, "non_existing_field", field2});
         baseTransaction.hdel(key4, new String[] {field1});
 
@@ -73,6 +74,7 @@ public static Object[] transactionTestResult() {
             0.5,
             2L,
             value1,
+            true,
             new String[] {value1, null, value2},
             1L,
             2L,