test: unit test for utils.go file in filesystem package (#999)

Signed-off-by: tarun8718 <[email protected]>

filesystem/test_data/copyfile/test.txt

@@ -0,0 +1 @@
+Some sample data to be copied

filesystem/utils_test.go

@@ -0,0 +1,81 @@
+/*
+ *  Copyright IBM Corporation 2023
+ *
+ *  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 (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/sirupsen/logrus"
+)
+
+func TestFileSystemUtils(t *testing.T) {
+	logrus.SetLevel(logrus.DebugLevel)
+
+	t.Run("test for copying file from source path to dest path with last modified time", func(t *testing.T) {
+		testDataFile := "test.txt"
+		destTempDir, err := ioutil.TempDir("", "destTempDir")
+		if err != nil {
+			t.Fatal("Error creating temp directory:", err)
+		}
+		defer os.RemoveAll(destTempDir)
+		testDataDir := "test_data"
+		sourceTempDir := "copyfile"
+
+		destFilePath := filepath.Join(destTempDir, testDataFile)
+		sourceFilePath, err := filepath.Abs(filepath.Join(testDataDir, sourceTempDir, testDataFile))
+		if err != nil {
+			t.Fatalf("unable to get absolute path for %s, %s. Error : %v", sourceTempDir, testDataFile, err)
+		}
+		sourceFileStat, err := os.Stat(sourceFilePath)
+		if err != nil {
+			t.Fatalf("Unable to stat file %s : %s", sourceFilePath, err)
+		}
+		sourceFileModTime := sourceFileStat.ModTime()
+		err = copyFile(destFilePath, sourceFilePath, sourceFileModTime)
+		if err != nil {
+			t.Fatalf("copyFile failed for destination file path %v, source file path %v. Error : %v", destFilePath, sourceFilePath, err)
+		}
+		destinationFileStat, err := os.Stat(destFilePath)
+		if err != nil {
+			t.Fatalf("unable to stat file %s : %s", destFilePath, err)
+		}
+		destFileModTime := destinationFileStat.ModTime()
+		if destFileModTime != sourceFileModTime {
+			t.Fatalf("mod times did not match. need %v, got %v", sourceFileModTime, destFileModTime)
+		}
+
+		sourceFileCont, err := os.ReadFile(sourceFilePath)
+		sourceFileContStr := string(sourceFileCont)
+		if err != nil {
+			t.Fatalf("unable to read content from file %v. Error : %v", sourceFileContStr, err)
+		}
+
+		destFileCont, err := os.ReadFile(destFilePath)
+		destFileContStr := string(destFileCont)
+		if err != nil {
+			t.Fatalf("unable to read content from file %v. Error : %v", destFileContStr, err)
+		}
+
+		if destFileContStr != sourceFileContStr {
+			t.Fatalf("destination file and source file content mismatch, test failed.")
+		}
+
+	})
+}