[SPARK-37031][SQL][TESTS] Unify v1 and v2 DESCRIBE NAMESPACE tests

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/DDLParserSuite.scala

@@ -1193,15 +1193,6 @@ class DDLParserSuite extends AnalysisTest {
         "DESC TABLE COLUMN for a specific partition is not supported"))
   }
 
-  test("describe database") {
-    val sql1 = "DESCRIBE DATABASE EXTENDED a.b"
-    val sql2 = "DESCRIBE DATABASE a.b"
-    comparePlans(parsePlan(sql1),
-      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
-    comparePlans(parsePlan(sql2),
-      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = false))
-  }
-
   test("SPARK-17328 Fix NPE with EXPLAIN DESCRIBE TABLE") {
     comparePlans(parsePlan("describe t"),
       DescribeRelation(

sql/core/src/test/scala/org/apache/spark/sql/connector/DataSourceV2SQLSuite.scala

@@ -1233,26 +1233,6 @@ class DataSourceV2SQLSuite
     assert(exception.getMessage.contains("Namespace 'ns1' not found"))
   }
 
-  test("DescribeNamespace using v2 catalog") {
-    withNamespace("testcat.ns1.ns2") {
-      sql("CREATE NAMESPACE IF NOT EXISTS testcat.ns1.ns2 COMMENT " +
-        "'test namespace' LOCATION '/tmp/ns_test'")
-      val descriptionDf = sql("DESCRIBE NAMESPACE testcat.ns1.ns2")
-      assert(descriptionDf.schema.map(field => (field.name, field.dataType)) ===
-        Seq(
-          ("info_name", StringType),
-          ("info_value", StringType)
-        ))
-      val description = descriptionDf.collect()
-      assert(description === Seq(
-        Row("Namespace Name", "ns2"),
-        Row(SupportsNamespaces.PROP_COMMENT.capitalize, "test namespace"),
-        Row(SupportsNamespaces.PROP_LOCATION.capitalize, "/tmp/ns_test"),
-        Row(SupportsNamespaces.PROP_OWNER.capitalize, defaultUser))
-      )
-    }
-  }
-
   test("ALTER NAMESPACE .. SET PROPERTIES using v2 catalog") {
     withNamespace("testcat.ns1.ns2") {
       sql("CREATE NAMESPACE IF NOT EXISTS testcat.ns1.ns2 COMMENT " +
@@ -2810,25 +2790,6 @@ class DataSourceV2SQLSuite
     }
   }
 
-  test("SPARK-34577: drop/add columns to a dataset of `DESCRIBE NAMESPACE`") {
-    withNamespace("ns") {
-      sql("CREATE NAMESPACE ns")
-      val description = sql(s"DESCRIBE NAMESPACE ns")
-      val noCommentDataset = description.drop("info_name")
-      val expectedSchema = new StructType()
-        .add(
-          name = "info_value",
-          dataType = StringType,
-          nullable = true,
-          metadata = new MetadataBuilder()
-            .putString("comment", "value of the namespace info").build())
-      assert(noCommentDataset.schema === expectedSchema)
-      val isNullDataset = noCommentDataset
-        .withColumn("is_null", noCommentDataset("info_value").isNull)
-      assert(isNullDataset.schema === expectedSchema.add("is_null", BooleanType, false))
-    }
-  }
-
   test("SPARK-34923: do not propagate metadata columns through Project") {
     val t1 = s"${catalogAndNamespace}table"
     withTable(t1) {

sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala

@@ -757,14 +757,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
 
         sql(s"CREATE DATABASE $dbName")
 
-        checkAnswer(
-          sql(s"DESCRIBE DATABASE EXTENDED $dbName").toDF("key", "value")
-            .where("key not like 'Owner%'"), // filter for consistency with in-memory catalog
-          Row("Database Name", dbNameWithoutBackTicks) ::
-            Row("Comment", "") ::
-            Row("Location", CatalogUtils.URIToString(location)) ::
-            Row("Properties", "") :: Nil)
-
         sql(s"ALTER DATABASE $dbName SET DBPROPERTIES ('a'='a', 'b'='b', 'c'='c')")
 
         checkAnswer(
@@ -813,7 +805,7 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
     }
   }
 
-  test("Drop/Alter/Describe Database - database does not exists") {
+  test("Drop/Alter Database - database does not exists") {
     val databaseNames = Seq("db1", "`database`")
 
     databaseNames.foreach { dbName =>
@@ -829,13 +821,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
         sql(s"ALTER DATABASE $dbName SET DBPROPERTIES ('d'='d')")
       }.getMessage
       assert(message.contains(s"Database '$dbNameWithoutBackTicks' not found"))
-
-      message = intercept[AnalysisException] {
-        sql(s"DESCRIBE DATABASE EXTENDED $dbName")
-      }.getMessage
-      assert(message.contains(s"Database '$dbNameWithoutBackTicks' not found"))
-
-      sql(s"DROP DATABASE IF EXISTS $dbName")
     }
   }
 

sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala

@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command
+
+import org.apache.spark.sql.catalyst.analysis.{AnalysisTest, UnresolvedNamespace}
+import org.apache.spark.sql.catalyst.parser.CatalystSqlParser.parsePlan
+import org.apache.spark.sql.catalyst.plans.logical.DescribeNamespace
+
+class DescribeNamespaceParserSuite extends AnalysisTest {
+  test("describe namespace") {
+    val sql1 = "DESCRIBE NAMESPACE EXTENDED a.b"
+    val sql2 = "DESCRIBE NAMESPACE a.b"
+    val sql3 = "DESCRIBE NAMESPACE cat.`database`"
+    comparePlans(parsePlan(sql1),
+      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
+    comparePlans(parsePlan(sql2),
+      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = false))
+    comparePlans(parsePlan(sql3),
+      DescribeNamespace(UnresolvedNamespace(Seq("cat", "database")), extended = false))
+  }
+}

sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command
+
+import org.apache.spark.sql.{AnalysisException, QueryTest}
+
+/**
+ * This base suite contains unified tests for the `DESCRIBE NAMESPACE` command that check V1 and V2
+ * table catalogs. The tests that cannot run for all supported catalogs are located in more
+ * specific test suites:
+ *
+ *   - V2 table catalog tests: `org.apache.spark.sql.execution.command.v2.DescribeNamespaceSuite`
+ *   - V1 table catalog tests:
+ *     `org.apache.spark.sql.execution.command.v1.DescribeNamespaceSuiteBase`
+ *     - V1 In-Memory catalog: `org.apache.spark.sql.execution.command.v1.DescribeNamespaceSuite`
+ *     - V1 Hive External catalog:
+*        `org.apache.spark.sql.hive.execution.command.DescribeNamespaceSuite`
+ */
+trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils {
+  override val command = "DESCRIBE NAMESPACE"
+
+  protected def notFoundMsgPrefix: String
+
+  test("namespace does not exists") {
+    val ns = "db1"
+    val message = intercept[AnalysisException] {
+      sql(s"DESCRIBE NAMESPACE EXTENDED $catalog.$ns")
+    }.getMessage
+
+    assert(message.contains(s"$notFoundMsgPrefix '$ns' not found"))
+
+    sql(s"DROP NAMESPACE IF EXISTS $catalog.$ns")
+  }
+}

sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command.v1
+
+import org.apache.spark.sql.Row
+import org.apache.spark.sql.execution.command
+
+/**
+ * This base suite contains unified tests for the `DESCRIBE NAMESPACE` command that checks V1
+ * table catalogs. The tests that cannot run for all V1 catalogs are located in more
+ * specific test suites:
+ *
+ *   - V1 In-Memory catalog: `org.apache.spark.sql.execution.command.v1.DescribeNamespaceSuite`
+ *   - V1 Hive External catalog:
+ *     `org.apache.spark.sql.hive.execution.command.DescribeNamespaceSuite`
+ */
+trait DescribeNamespaceSuiteBase extends command.DescribeNamespaceSuiteBase {
+  override def notFoundMsgPrefix: String = "Database"
+
+  test("basic") {
+    val ns = "db1"
+    withNamespace(ns) {
+      sql(s"CREATE NAMESPACE $ns")
+
+      val result = sql(s"DESCRIBE NAMESPACE EXTENDED $ns")
+        .toDF("key", "value")
+        .where("key not like 'Owner%'") // filter for consistency with in-memory catalog
+        .collect()
+
+      assert(result.length == 4)
+      assert(result(0) === Row("Database Name", ns))
+      assert(result(1) === Row("Comment", ""))
+      // Check only the key for "Location" since its value depends on warehouse path, etc.
+      assert(result(2).getString(0) === "Location")
+      assert(result(3) === Row("Properties", ""))
+    }
+  }
+}
+
+/**
+ * The class contains tests for the `DESCRIBE NAMESPACE` command to check V1 In-Memory
+ * table catalog.
+ */
+class DescribeNamespaceSuite extends DescribeNamespaceSuiteBase with CommandSuiteBase

sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala

@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command.v2
+
+import org.apache.spark.sql.Row
+import org.apache.spark.sql.connector.catalog.SupportsNamespaces
+import org.apache.spark.sql.execution.command
+import org.apache.spark.sql.types.{BooleanType, MetadataBuilder, StringType, StructType}
+import org.apache.spark.util.Utils
+
+/**
+ * The class contains tests for the `DESCRIBE NAMESPACE` command to check V2 table catalogs.
+ */
+class DescribeNamespaceSuite extends command.DescribeNamespaceSuiteBase with CommandSuiteBase {
+  override def notFoundMsgPrefix: String = "Namespace"
+
+  test("DescribeNamespace using v2 catalog") {
+    withNamespace(s"$catalog.ns1.ns2") {
+      sql(s"CREATE NAMESPACE IF NOT EXISTS $catalog.ns1.ns2 COMMENT " +
+        "'test namespace' LOCATION '/tmp/ns_test'")
+      val descriptionDf = sql(s"DESCRIBE NAMESPACE $catalog.ns1.ns2")
+      assert(descriptionDf.schema.map(field => (field.name, field.dataType)) ===
+        Seq(
+          ("info_name", StringType),
+          ("info_value", StringType)
+        ))
+      val description = descriptionDf.collect()
+      assert(description === Seq(
+        Row("Namespace Name", "ns2"),
+        Row(SupportsNamespaces.PROP_COMMENT.capitalize, "test namespace"),
+        Row(SupportsNamespaces.PROP_LOCATION.capitalize, "/tmp/ns_test"),
+        Row(SupportsNamespaces.PROP_OWNER.capitalize, Utils.getCurrentUserName()))
+      )
+    }
+  }
+
+  test("SPARK-34577: drop/add columns to a dataset of `DESCRIBE NAMESPACE`") {
+    withNamespace("ns") {
+      sql("CREATE NAMESPACE ns")
+      val description = sql(s"DESCRIBE NAMESPACE ns")
+      val noCommentDataset = description.drop("info_name")
+      val expectedSchema = new StructType()
+        .add(
+          name = "info_value",
+          dataType = StringType,
+          nullable = true,
+          metadata = new MetadataBuilder()
+            .putString("comment", "value of the namespace info").build())
+      assert(noCommentDataset.schema === expectedSchema)
+      val isNullDataset = noCommentDataset
+        .withColumn("is_null", noCommentDataset("info_value").isNull)
+      assert(isNullDataset.schema === expectedSchema.add("is_null", BooleanType, false))
+    }
+  }
+}

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/command/DescribeNamespaceSuite.scala

@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.hive.execution.command
+
+import org.apache.spark.sql.execution.command.v1
+
+/**
+ * The class contains tests for the `DESCRIBE NAMESPACE` command to check V1 Hive external
+ * table catalog.
+ */
+class DescribeNamespaceSuite extends v1.DescribeNamespaceSuiteBase with CommandSuiteBase