Bug fix, return object type for field which has implicit object datat…

…ype when describe the table (opendistro-for-elasticsearch#377)

* Bug fix, return object type for field which has implicit object datatype when describe the table

(cherry picked from commit c30e342)

src/main/java/com/amazon/opendistroforelasticsearch/sql/executor/format/DescribeResultSet.java

@@ -36,6 +36,12 @@ public class DescribeResultSet extends ResultSet {
     private static final int DEFAULT_NUM_PREC_RADIX = 10;
     private static final String IS_AUTOINCREMENT = "NO";
 
+    /**
+     * You are not required to set the field type to object explicitly, as this is the default value.
+     * https://www.elastic.co/guide/en/elasticsearch/reference/current/object.html
+     */
+    private static final String DEFAULT_OBJECT_DATATYPE = "object";
+
     private IndexStatement statement;
     private Object queryResult;
 
@@ -159,7 +165,7 @@ private Map<String, String> flattenMappingMetaData(Map<String, Object> mappingMe
             Map<String, Object> metaData = (Map<String, Object>) entry.getValue();
 
             String fullPath = addToPath(currPath, entry.getKey());
-            flattenedMapping.put(fullPath, (String) metaData.get("type"));
+            flattenedMapping.put(fullPath, (String) metaData.getOrDefault("type", DEFAULT_OBJECT_DATATYPE));
             if (metaData.containsKey("properties")) {
                 flattenedMapping = flattenMappingMetaData(metaData, fullPath, flattenedMapping);
             }

src/test/java/com/amazon/opendistroforelasticsearch/sql/esintgtest/MetaDataQueriesIT.java

@@ -16,14 +16,19 @@
 package com.amazon.opendistroforelasticsearch.sql.esintgtest;
 
 import org.elasticsearch.client.Request;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeMatcher;
 import org.json.JSONArray;
 import org.json.JSONObject;
 import org.junit.Test;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
+import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_GAME_OF_THRONES;
+import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifySome;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.hasItems;
@@ -290,6 +295,31 @@ public void describeSingleIndex() throws IOException {
         assertThat(row.get(5), not(equalTo(JSONObject.NULL)));
     }
 
+    @Test
+    public void describeSingleIndexWithObjectFieldShouldPass() throws IOException {
+        JSONObject response =
+                executeQuery(String.format("DESCRIBE TABLES LIKE %s", TEST_INDEX_GAME_OF_THRONES));
+
+        // Schema for DESCRIBE is filled with a lot of fields that aren't used so only the important
+        // ones are checked for here
+        String[] fields = {"TABLE_NAME", "COLUMN_NAME", "TYPE_NAME"};
+        checkContainsColumns(getSchema(response), fields);
+
+        JSONArray dataRows = getDataRows(response);
+        assertThat(dataRows.length(), greaterThan(0));
+        assertThat(dataRows.getJSONArray(0).length(), equalTo(DESCRIBE_FIELD_LENGTH));
+
+        verifySome(dataRows,
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "nickname", "text"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "name", "object"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "name.firstname", "text"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "name.lastname", "text"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "name.ofHerName", "integer"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "name.ofHisName", "integer"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "house", "text"),
+                   describeRow(TEST_INDEX_GAME_OF_THRONES, "gender", "text"));
+    }
+
     @Test
     public void describeCaseSensitivityCheck() throws IOException {
         JSONObject response = executeQuery(String.format("describe tables like %s", TestsConstants.TEST_INDEX_ACCOUNT));
@@ -374,4 +404,25 @@ private String getClusterName() throws IOException {
         String response = executeRequest(new Request("GET", "_cluster/health"));
         return new JSONObject(response).optString("cluster_name", "");
     }
+
+    public static TypeSafeMatcher<JSONArray> describeRow(Object... expectedObjects) {
+        return new TypeSafeMatcher<JSONArray>() {
+            @Override
+            public void describeTo(Description description) {
+                description.appendText(String.join(",", Arrays.asList(expectedObjects).toString()));
+            }
+
+            @Override
+            protected boolean matchesSafely(JSONArray array) {
+                List<Object> actualObjects = new ArrayList<>();
+                // TABLE_NAME
+                actualObjects.add(array.get(2));
+                // COLUMN_NAME
+                actualObjects.add(array.get(3));
+                // TYPE_NAME
+                actualObjects.add(array.get(5));
+                return Arrays.asList(expectedObjects).equals(actualObjects);
+            }
+        };
+    }
 }

src/test/java/com/amazon/opendistroforelasticsearch/sql/util/MatcherUtils.java

@@ -34,9 +34,9 @@
 import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.arrayContaining;
 import static org.hamcrest.Matchers.arrayContainingInAnyOrder;
-import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.emptyArray;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.hasEntry;
 import static org.hamcrest.Matchers.hasItems;
 import static org.junit.Assert.assertEquals;
@@ -148,6 +148,17 @@ public static <T> void verify(JSONArray array, Matcher<T>... matchers) {
         assertThat(objects, containsInAnyOrder(matchers));
     }
 
+    @SuppressWarnings("unchecked")
+    public static <T> void verifySome(JSONArray array, Matcher<T>... matchers) {
+        List<T> objects = new ArrayList<>();
+        array.iterator().forEachRemaining(o -> objects.add((T) o));
+
+        assertThat(matchers.length, greaterThan(0));
+        for (Matcher<T> matcher : matchers) {
+            assertThat(objects, hasItems(matcher));
+        }
+    }
+
     public static TypeSafeMatcher<JSONObject> schema(String expectedName, String expectedAlias, String expectedType) {
         return new TypeSafeMatcher<JSONObject>() {
             @Override