[SPARK-27618][SQL][FOLLOW-UP] Unnecessary access to externalCatalog

## What changes were proposed in this pull request?
This PR is to add test cases for ensuring that we do not have unnecessary access to externalCatalog.

In the future, we can follow these examples to improve our test coverage in this area.

## How was this patch tested?
N/A

Closes apache#24511 from gatorsmile/addTestcaseSpark-27618.

Authored-by: gatorsmile <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: gatorsmile

sql/catalyst/pom.xml

@@ -71,6 +71,11 @@
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
 
     <dependency>
       <groupId>org.apache.spark</groupId>

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/AnalysisExternalCatalogSuite.scala

@@ -0,0 +1,74 @@
+/*
+ * 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.catalyst.analysis
+
+import java.net.URI
+
+import org.mockito.Mockito._
+import org.scalatest.Matchers
+
+import org.apache.spark.sql.catalyst.{FunctionIdentifier, TableIdentifier}
+import org.apache.spark.sql.catalyst.catalog.{CatalogDatabase, CatalogStorageFormat, CatalogTable, CatalogTableType, ExternalCatalog, InMemoryCatalog, SessionCatalog}
+import org.apache.spark.sql.catalyst.expressions.{Alias, AttributeReference}
+import org.apache.spark.sql.catalyst.plans.logical.{LocalRelation, Project}
+import org.apache.spark.sql.internal.SQLConf
+import org.apache.spark.sql.types._
+
+class AnalysisExternalCatalogSuite extends AnalysisTest with Matchers {
+  private def getAnalyzer(externCatalog: ExternalCatalog): Analyzer = {
+    val conf = new SQLConf()
+    val catalog = new SessionCatalog(externCatalog, FunctionRegistry.builtin, conf)
+    catalog.createDatabase(
+      CatalogDatabase("default", "", new URI("loc"), Map.empty),
+      ignoreIfExists = false)
+    catalog.createTable(
+      CatalogTable(
+        TableIdentifier("t1", Some("default")),
+        CatalogTableType.MANAGED,
+        CatalogStorageFormat.empty,
+        StructType(Seq(StructField("a", IntegerType, nullable = true)))),
+      ignoreIfExists = false)
+    new Analyzer(catalog, conf)
+  }
+
+  test("query builtin functions don't call the external catalog") {
+    val inMemoryCatalog = new InMemoryCatalog
+    val catalog = spy(inMemoryCatalog)
+    val analyzer = getAnalyzer(catalog)
+    reset(catalog)
+    val testRelation = LocalRelation(AttributeReference("a", IntegerType, nullable = true)())
+    val func =
+      Alias(UnresolvedFunction("sum", Seq(UnresolvedAttribute("a")), isDistinct = false), "s")()
+    val plan = Project(Seq(func), testRelation)
+    analyzer.execute(plan)
+    verifyZeroInteractions(catalog)
+  }
+
+  test("check the existence of builtin functions don't call the external catalog") {
+    val inMemoryCatalog = new InMemoryCatalog
+    val externCatalog = spy(inMemoryCatalog)
+    val catalog = new SessionCatalog(externCatalog, FunctionRegistry.builtin, conf)
+    catalog.createDatabase(
+      CatalogDatabase("default", "", new URI("loc"), Map.empty),
+      ignoreIfExists = false)
+    reset(externCatalog)
+    catalog.functionExists(FunctionIdentifier("sum"))
+    verifyZeroInteractions(externCatalog)
+  }
+
+}