add ProtoBugCompareConsistencyTest

generators/src/org/jetbrains/kotlin/generators/protobuf/GenerateProtoBufCompare.kt

@@ -32,11 +32,11 @@ class GenerateProtoBufCompare {
 
         platformStatic
         fun main(args: Array<String>) {
-            generate()
+            generate(DEST_FILE)
         }
 
-        fun generate() {
-            GeneratorsFileUtil.writeFileIfContentChanged(DEST_FILE, GenerateProtoBufCompare().generate())
+        fun generate(destFile: File) {
+            GeneratorsFileUtil.writeFileIfContentChanged(destFile, GenerateProtoBufCompare().generate())
         }
     }
 

generators/tests/org/jetbrains/kotlin/generators/protobuf/ProtoBufCompareConsistencyTest.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed 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.jetbrains.kotlin.generators.protobuf
+
+import com.intellij.openapi.util.io.FileUtil
+import com.intellij.testFramework.UsefulTestCase
+import org.jetbrains.kotlin.test.JetTestUtils
+import java.io.File
+
+public class ProtoBufCompareConsistencyTest : UsefulTestCase() {
+    public fun testAlreadyGenerated() {
+        val testDir = JetTestUtils.tmpDir("testDirectory")
+        val newFile = File(testDir, "ProtoCompareGenerated.kt")
+        GenerateProtoBufCompare.generate(newFile)
+
+        JetTestUtils.assertEqualsToFile(newFile, FileUtil.loadFile(GenerateProtoBufCompare.DEST_FILE))
+    }
+}