test: add tests for replicateProcessFileCallBack (#1066)

* test: add tests for replicateProcessFileCallBack
* refactor: add IBM licence header, update test names, check copied file contents, use static empty file for testing

Signed-off-by: prakharagarwal1 <prakharagarwal3031@gmail.com>

filesystem/replicator_test.go

@@ -0,0 +1,139 @@
+/*
+ *  Copyright IBM Corporation 2021
+ *
+ *  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 filesystem
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+ func TestReplicateProcessFileCallBack(t *testing.T) {
+	 t.Run("test for source file does not exist, should return an error", func(t *testing.T) {
+		 sourceFilePath := "test_data/replicator_test/non_existent_file.txt"
+		 destinationFilePath := "test_data/replicator_test/destination.txt"
+		 err := replicateProcessFileCallBack(sourceFilePath, destinationFilePath, nil)
+		 if err == nil {
+			 t.Errorf("Expected error for non-existent source file, got nil")
+		 }
+	 })
+
+	 t.Run("test for destination file doesn't exist, should copy the source file", func(t *testing.T) {
+		 sourceFilePath := "test_data/replicator_test/emptyfile.txt"
+		 destinationFilePath := "test_data/replicator_test/destination_file.txt"
+
+		 err := replicateProcessFileCallBack(sourceFilePath, destinationFilePath, nil)
+		 if err != nil {
+			 t.Errorf("Expected nil error, got: %s", err)
+		 }
+
+		 os.Remove(destinationFilePath)
+	 })
+
+	 t.Run("test for destination file exists but is different, should copy the source file", func(t *testing.T) {
+		 sourceFilePath := "test_data/replicator_test/source_file.txt"
+		 destinationFilePath := "test_data/replicator_test/destination_file.txt"
+
+		 sourceFile, err := os.Create(sourceFilePath)
+		 if err != nil {
+			 t.Fatal(err)
+		 }
+		 defer func() {
+			 sourceFile.Close()
+			 os.Remove(sourceFilePath)
+		 }()
+
+		 _, err = sourceFile.WriteString("hello, world!")
+		 if err != nil {
+			 t.Fatal(err)
+		 }
+
+		 destinationFile, err := os.Create(destinationFilePath)
+		 if err != nil {
+			 t.Fatal(err)
+		 }
+		 defer func() {
+			 destinationFile.Close()
+			 os.Remove(destinationFilePath)
+		 }()
+
+		 _, err = destinationFile.WriteString("hello, go!")
+		 if err != nil {
+			 t.Fatal(err)
+		 }
+
+		 err = replicateProcessFileCallBack(sourceFilePath, destinationFilePath, nil)
+		 if err != nil {
+			 t.Errorf("Expected nil error, got: %s", err)
+		 }
+
+		 // Check if the source file content matches the destination file content after copying
+		 sourceContent, err := ioutil.ReadFile(sourceFilePath)
+		 if err != nil {
+			 t.Fatal(err)
+		 }
+
+		 destinationContent, err := ioutil.ReadFile(destinationFilePath)
+		 if err != nil {
+			 t.Fatal(err)
+		 }
+
+		 if !bytes.Equal(sourceContent, destinationContent) {
+			 t.Errorf("Expected destination content to be equal to source content, but they are different.")
+		 }
+	 })
+
+	 t.Run("test for destination file exists and is the same, should return nil without copying", func(t *testing.T) {
+		 sourceFilePath := "test_data/replicator_test/source_same.txt"
+		 destinationFilePath := "test_data/replicator_test/destination_same.txt"
+
+		 // Store the destination file's modification time before calling replicateProcessFileCallBack
+		info, err := os.Stat(destinationFilePath)
+		if err != nil {
+			t.Errorf("Destination file should exist, but got an error: %s", err)
+		}
+		 originalModTime := info.ModTime()
+		 err = replicateProcessFileCallBack(sourceFilePath, destinationFilePath, nil)
+		 if err != nil {
+			 t.Errorf("Expected nil error, got: %s", err)
+		 }
+
+		 // Check if the destination file still exists after calling replicateProcessFileCallBack
+		info, err = os.Stat(destinationFilePath)
+		if err != nil {
+			t.Errorf("Destination file should exist, but got an error: %s", err)
+		}
+
+		// Check if the destination file's modification time hasn't changed
+		updatedModTime := info.ModTime()
+		if !updatedModTime.Equal(originalModTime) {
+			t.Errorf("Destination file's modification time has changed, expected: %v, got: %v", originalModTime, updatedModTime)
+		}
+
+		// Check if the destination file content remains unchanged
+		destinationContent, err := ioutil.ReadFile(destinationFilePath)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !bytes.Equal(destinationContent, []byte("hello, world!")) {
+			t.Errorf("Expected destination content to remain unchanged, but got different content.")
+		}
+	 })
+ }
+

filesystem/test_data/replicator_test/destination_same.txt

@@ -0,0 +1 @@
+hello, world!

filesystem/test_data/replicator_test/source_same.txt

@@ -0,0 +1 @@
+hello, world!