From 10186a303254e146f00ec3c0ad238582dfc7cdd3 Mon Sep 17 00:00:00 2001
From: SanHalacogluImproving
 <144171266+SanHalacogluImproving@users.noreply.github.com>
Date: Mon, 4 Mar 2024 15:42:47 -0800
Subject: [PATCH] Java: Add LLen command. (List Commands) (#1042)

* Java: Add LLen command. (List Commands)

* Added examples.

* Star import fix.

* Rebase Spotless.
---
 .../src/main/java/glide/api/BaseClient.java   |  6 +++++
 .../glide/api/commands/ListBaseCommands.java  | 15 ++++++++++++
 .../glide/api/models/BaseTransaction.java     | 16 +++++++++++++
 .../test/java/glide/api/RedisClientTest.java  | 24 +++++++++++++++++++
 .../glide/api/models/TransactionTests.java    |  4 ++++
 .../test/java/glide/SharedCommandTests.java   | 19 +++++++++++++++
 .../java/glide/TransactionTestUtilities.java  |  2 ++
 7 files changed, 86 insertions(+)

diff --git a/java/client/src/main/java/glide/api/BaseClient.java b/java/client/src/main/java/glide/api/BaseClient.java
index b345902957..1b78309d34 100644
--- a/java/client/src/main/java/glide/api/BaseClient.java
+++ b/java/client/src/main/java/glide/api/BaseClient.java
@@ -22,6 +22,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.Incr;
 import static redis_request.RedisRequestOuterClass.RequestType.IncrBy;
 import static redis_request.RedisRequestOuterClass.RequestType.IncrByFloat;
+import static redis_request.RedisRequestOuterClass.RequestType.LLen;
 import static redis_request.RedisRequestOuterClass.RequestType.LPop;
 import static redis_request.RedisRequestOuterClass.RequestType.LPush;
 import static redis_request.RedisRequestOuterClass.RequestType.LRange;
@@ -377,6 +378,11 @@ public CompletableFuture<String> ltrim(@NonNull String key, long start, long end
                 this::handleStringResponse);
     }
 
+    @Override
+    public CompletableFuture<Long> llen(@NonNull String key) {
+        return commandManager.submitNewCommand(LLen, new String[] {key}, this::handleLongResponse);
+    }
+
     @Override
     public CompletableFuture<Long> rpush(@NonNull String key, @NonNull String[] elements) {
         String[] arguments = ArrayUtils.addFirst(elements, key);
diff --git a/java/client/src/main/java/glide/api/commands/ListBaseCommands.java b/java/client/src/main/java/glide/api/commands/ListBaseCommands.java
index 948f91b52a..053f0d6697 100644
--- a/java/client/src/main/java/glide/api/commands/ListBaseCommands.java
+++ b/java/client/src/main/java/glide/api/commands/ListBaseCommands.java
@@ -122,6 +122,21 @@ public interface ListBaseCommands {
      */
     CompletableFuture<String> ltrim(String key, long start, long end);
 
+    /**
+     * Returns the length of the list stored at <code>key</code>.
+     *
+     * @see <a href="https://redis.io/commands/llen/">redis.io</a> for details.
+     * @param key The key of the list.
+     * @return The length of the list at <code>key</code>.<br>
+     *     If <code>key</code> does not exist, it is interpreted as an empty list and 0 is returned.
+     * @example
+     *     <pre>
+     * Long lenList = client.llen("my_list").get()
+     * assert lenList == 3L //Indicates that there are 3 elements in the list.
+     * </pre>
+     */
+    CompletableFuture<Long> llen(String key);
+
     /**
      * Inserts all the specified values at the tail of the list stored at <code>key</code>.<br>
      * <code>elements</code> are inserted one after the other to the tail of the list, from the
diff --git a/java/client/src/main/java/glide/api/models/BaseTransaction.java b/java/client/src/main/java/glide/api/models/BaseTransaction.java
index e1d2443a83..d5ca352558 100644
--- a/java/client/src/main/java/glide/api/models/BaseTransaction.java
+++ b/java/client/src/main/java/glide/api/models/BaseTransaction.java
@@ -22,6 +22,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.IncrBy;
 import static redis_request.RedisRequestOuterClass.RequestType.IncrByFloat;
 import static redis_request.RedisRequestOuterClass.RequestType.Info;
+import static redis_request.RedisRequestOuterClass.RequestType.LLen;
 import static redis_request.RedisRequestOuterClass.RequestType.LPop;
 import static redis_request.RedisRequestOuterClass.RequestType.LPush;
 import static redis_request.RedisRequestOuterClass.RequestType.LRange;
@@ -580,6 +581,21 @@ public T ltrim(@NonNull String key, long start, long end) {
         return getThis();
     }
 
+    /**
+     * Returns the length of the list stored at <code>key</code>.
+     *
+     * @see <a href="https://redis.io/commands/llen/">redis.io</a> for details.
+     * @param key The key of the list.
+     * @return Command Response - The length of the list at <code>key</code>.<br>
+     *     If <code>key</code> does not exist, it is interpreted as an empty list and 0 is returned.
+     */
+    public T llen(@NonNull String key) {
+        ArgsArray commandArgs = buildArgs(key);
+
+        protobufTransaction.addCommands(buildCommand(LLen, commandArgs));
+        return getThis();
+    }
+
     /**
      * Inserts all the specified values at the tail of the list stored at <code>key</code>.<br>
      * <code>elements</code> are inserted one after the other to the tail of the list, from the
diff --git a/java/client/src/test/java/glide/api/RedisClientTest.java b/java/client/src/test/java/glide/api/RedisClientTest.java
index 9a8fcd6aed..b8f89ac6d9 100644
--- a/java/client/src/test/java/glide/api/RedisClientTest.java
+++ b/java/client/src/test/java/glide/api/RedisClientTest.java
@@ -32,6 +32,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.IncrBy;
 import static redis_request.RedisRequestOuterClass.RequestType.IncrByFloat;
 import static redis_request.RedisRequestOuterClass.RequestType.Info;
+import static redis_request.RedisRequestOuterClass.RequestType.LLen;
 import static redis_request.RedisRequestOuterClass.RequestType.LPop;
 import static redis_request.RedisRequestOuterClass.RequestType.LPush;
 import static redis_request.RedisRequestOuterClass.RequestType.LRange;
@@ -1093,6 +1094,29 @@ public void ltrim_returns_success() {
         assertEquals(OK, payload);
     }
 
+    @SneakyThrows
+    @Test
+    public void llen_returns_success() {
+        // setup
+        String key = "testKey";
+        String[] args = new String[] {key};
+        long value = 2L;
+
+        CompletableFuture<Long> testResponse = mock(CompletableFuture.class);
+        when(testResponse.get()).thenReturn(value);
+
+        // match on protobuf request
+        when(commandManager.<Long>submitNewCommand(eq(LLen), eq(args), any())).thenReturn(testResponse);
+
+        // exercise
+        CompletableFuture<Long> response = service.llen(key);
+        Long payload = response.get();
+
+        // verify
+        assertEquals(testResponse, response);
+        assertEquals(value, payload);
+    }
+
     @SneakyThrows
     @Test
     public void rpush_returns_success() {
diff --git a/java/client/src/test/java/glide/api/models/TransactionTests.java b/java/client/src/test/java/glide/api/models/TransactionTests.java
index 0a86c6dbee..89a507fbb7 100644
--- a/java/client/src/test/java/glide/api/models/TransactionTests.java
+++ b/java/client/src/test/java/glide/api/models/TransactionTests.java
@@ -22,6 +22,7 @@
 import static redis_request.RedisRequestOuterClass.RequestType.IncrBy;
 import static redis_request.RedisRequestOuterClass.RequestType.IncrByFloat;
 import static redis_request.RedisRequestOuterClass.RequestType.Info;
+import static redis_request.RedisRequestOuterClass.RequestType.LLen;
 import static redis_request.RedisRequestOuterClass.RequestType.LPop;
 import static redis_request.RedisRequestOuterClass.RequestType.LPush;
 import static redis_request.RedisRequestOuterClass.RequestType.LRange;
@@ -175,6 +176,9 @@ public void transaction_builds_protobuf_request(BaseTransaction<?> transaction)
         results.add(
                 Pair.of(LTrim, ArgsArray.newBuilder().addArgs("key").addArgs("1").addArgs("2").build()));
 
+        transaction.llen("key");
+        results.add(Pair.of(LLen, ArgsArray.newBuilder().addArgs("key").build()));
+
         transaction.rpush("key", new String[] {"element"});
         results.add(Pair.of(RPush, ArgsArray.newBuilder().addArgs("key").addArgs("element").build()));
 
diff --git a/java/integTest/src/test/java/glide/SharedCommandTests.java b/java/integTest/src/test/java/glide/SharedCommandTests.java
index 1776dc5332..26acf92eda 100644
--- a/java/integTest/src/test/java/glide/SharedCommandTests.java
+++ b/java/integTest/src/test/java/glide/SharedCommandTests.java
@@ -603,6 +603,25 @@ public void ltrim_existing_non_existing_key_and_type_error(BaseClient client) {
         assertTrue(ltrimException.getCause() instanceof RequestException);
     }
 
+    @SneakyThrows
+    @ParameterizedTest
+    @MethodSource("getClients")
+    public void llen_existing_non_existing_key_and_type_error(BaseClient client) {
+        String key1 = UUID.randomUUID().toString();
+        String key2 = UUID.randomUUID().toString();
+        String[] valueArray = new String[] {"value4", "value3", "value2", "value1"};
+
+        assertEquals(4, client.lpush(key1, valueArray).get());
+        assertEquals(4, client.llen(key1).get());
+        assertEquals(0, client.llen("non_existing_key").get());
+
+        assertEquals(OK, client.set(key2, "foo").get());
+
+        Exception lrangeException =
+                assertThrows(ExecutionException.class, () -> client.llen(key2).get());
+        assertTrue(lrangeException.getCause() instanceof RequestException);
+    }
+
     @SneakyThrows
     @ParameterizedTest
     @MethodSource("getClients")
diff --git a/java/integTest/src/test/java/glide/TransactionTestUtilities.java b/java/integTest/src/test/java/glide/TransactionTestUtilities.java
index 61db76a57c..3524d7e26d 100644
--- a/java/integTest/src/test/java/glide/TransactionTestUtilities.java
+++ b/java/integTest/src/test/java/glide/TransactionTestUtilities.java
@@ -64,6 +64,7 @@ public static BaseTransaction<?> transactionTest(BaseTransaction<?> baseTransact
         baseTransaction.hincrByFloat(key4, field3, 5.5);
 
         baseTransaction.lpush(key5, new String[] {value1, value2, value3, value3});
+        baseTransaction.llen(key5);
         baseTransaction.ltrim(key5, 1, -1);
         baseTransaction.lrange(key5, 0, -2);
         baseTransaction.lpop(key5);
@@ -109,6 +110,7 @@ public static Object[] transactionTestResult() {
             5L,
             10.5,
             4L,
+            4L,
             OK,
             new String[] {value3, value2},
             value3,