[SPARK-14127][SQL] Makes 'DESC [EXTENDED|FORMATTED] <table>' support data source tables

## What changes were proposed in this pull request?

This is a follow-up of PR #12844. It makes the newly updated `DescribeTableCommand` to support data sources tables.

## How was this patch tested?

A test case is added to check `DESC [EXTENDED | FORMATTED] <table>` output.

Author: Cheng Lian <lian@databricks.com>

Closes #12934 from liancheng/spark-14127-desc-table-follow-up.

1 files changed, 18 insertions, 1 deletions

diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala
index d55ddb251d..aa5b5e6309 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala
@@ -365,7 +365,7 @@ class HiveDDLSuite
     }
   }
 
-  test("desc table") {
+  test("desc table for Hive table") {
     withTable("tab1") {
       val tabName = "tab1"
       sql(s"CREATE TABLE $tabName(c1 int)")
@@ -503,4 +503,21 @@ class HiveDDLSuite
     }.getMessage
     assert(message.contains("Can not drop default database"))
   }
+
+  test("desc table for data source table") {
+    withTable("tab1") {
+      val tabName = "tab1"
+      sqlContext.range(1).write.format("json").saveAsTable(tabName)
+
+      assert(sql(s"DESC $tabName").collect().length == 1)
+
+      assert(
+        sql(s"DESC FORMATTED $tabName").collect()
+          .exists(_.getString(0) == "# Storage Information"))
+
+      assert(
+        sql(s"DESC EXTENDED $tabName").collect()
+          .exists(_.getString(0) == "# Detailed Table Information"))
+    }
+  }
 }