Implement JavaOnlyArray#getType

Reviewed By: AaaChiuuu

Differential Revision: D3504601

fbshipit-source-id: 37dbbcdd8cc0523cb8f1673047995c4410e8f7be

ReactAndroid/src/main/java/com/facebook/react/bridge/JavaOnlyArray.java

@@ -90,6 +90,23 @@ public class JavaOnlyArray implements ReadableArray, WritableArray {
 
   @Override
   public ReadableType getType(int index) {
+    Object object = mBackingList.get(index);
+
+    if (object == null) {
+      return ReadableType.Null;
+    } else if (object instanceof Boolean) {
+      return ReadableType.Boolean;
+    } else if (object instanceof Double ||
+        object instanceof Float ||
+        object instanceof Integer) {
+      return ReadableType.Number;
+    } else if (object instanceof String) {
+      return ReadableType.String;
+    } else if (object instanceof ReadableArray) {
+      return ReadableType.Array;
+    } else if (object instanceof ReadableMap) {
+      return ReadableType.Map;
+    }
     return null;
   }
 

ReactAndroid/src/test/java/com/facebook/react/bridge/JavaOnlyArrayTest.java

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.bridge;
+
+import org.junit.Test;
+
+import static org.fest.assertions.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link JavaOnlyArray}
+ */
+public class JavaOnlyArrayTest {
+
+  @Test
+  public void testGetType() throws Exception {
+    JavaOnlyArray values = JavaOnlyArray.of(
+        1,
+        2f,
+        3.,
+        "4",
+        false,
+        JavaOnlyArray.of(),
+        JavaOnlyMap.of(),
+        null);
+    ReadableType[] expectedTypes = new ReadableType[] {
+      ReadableType.Number,
+      ReadableType.Number,
+      ReadableType.Number,
+      ReadableType.String,
+      ReadableType.Boolean,
+      ReadableType.Array,
+      ReadableType.Map,
+      ReadableType.Null
+    };
+
+    for (int i = 0; i < values.size(); i++) {
+      assertThat(values.getType(i)).isEqualTo(expectedTypes[i]);
+    }
+  }
+}