feat: Add createOrGetCache method to the SDK (#86)

* feat: Add createOrGetCache method to the SDK

* add test

* fix formatting

momento-sdk/src/intTest/java/momento/sdk/MomentoTest.java

@@ -50,12 +50,20 @@ void testHappyPath() {
     runHappyPathTest(momento, cacheName);
   }
 
+  @Test
+  void recreatingCacheWithSameName_throwsAlreadyExists() {
+    Momento momento = Momento.builder(authToken).build();
+    momento.createOrGetCache(cacheName);
+    assertThrows(CacheAlreadyExistsException.class, () -> momento.createCache(cacheName));
+  }
+
   @Test
   void testInvalidCacheName() {
     Momento momento =
         Momento.builder(authToken).endpointOverride(DEFAULT_MOMENTO_HOSTED_ZONE_ENDPOINT).build();
 
-    assertThrows(InvalidArgumentException.class, () -> getOrCreate(momento, "     "));
+    assertThrows(InvalidArgumentException.class, () -> momento.createCache("     "));
+    assertThrows(InvalidArgumentException.class, () -> momento.createOrGetCache("     "));
   }
 
   @Test
@@ -82,7 +90,7 @@ void deleteForNonExistantCache_throwsNotFound() {
   }
 
   private static void runHappyPathTest(Momento momento, String cacheName) {
-    Cache cache = getOrCreate(momento, cacheName);
+    Cache cache = momento.createOrGetCache(cacheName);
 
     String key = java.util.UUID.randomUUID().toString();
 
@@ -96,14 +104,4 @@ private static void runHappyPathTest(Momento momento, String cacheName) {
     assertEquals(MomentoCacheResult.Hit, rsp.result());
     assertEquals("bar", rsp.asStringUtf8().get());
   }
-
-  // TODO: Update this to be recreated each time and add a separate test case for Already Exists
-  private static Cache getOrCreate(Momento momento, String cacheName) {
-    try {
-      momento.createCache(cacheName);
-    } catch (CacheAlreadyExistsException e) {
-      // Just get Cache following a successful create
-    }
-    return momento.getCache(cacheName);
-  }
 }

momento-sdk/src/main/java/momento/sdk/Momento.java

@@ -96,6 +96,27 @@ public DeleteCacheResponse deleteCache(String cacheName) {
     }
   }
 
+  /**
+   * Creates a client to interact with the given cache name.
+   *
+   * <p>If a cache with given name already exists then returns a client to interact with the cache.
+   * Otherwise, first creates a new Momento Cache and then returns a client to interact with the
+   * newly created cache.
+   *
+   * @param cacheName
+   * @return {@link Cache} client to perform operations against the Momento Cache with the provided
+   *     name.
+   */
+  public Cache createOrGetCache(String cacheName) {
+    checkCacheNameValid(cacheName);
+    try {
+      createCache(cacheName);
+    } catch (CacheAlreadyExistsException e) {
+      // This implies that cache with the given name already exists. Just create a client.
+    }
+    return getCache(cacheName);
+  }
+
   public Cache getCache(String cacheName) {
     checkCacheNameValid(cacheName);
     return makeCacheClient(authToken, cacheName, momentoEndpoints.cacheEndpoint());