Bring the message to the users back

datasetUtils/getAvailableDatasets.go

@@ -26,6 +26,7 @@ func GetAvailableDatasets(username string, RSYNCServer string, singleDatasetId s
 	if singleDatasetId != "" {
 		datasetList = append(datasetList, formatDatasetId(singleDatasetId))
 	} else {
+		printMessage(RSYNCServer)
 		datasets, err := fetchDatasetsFromServer(username, RSYNCServer)
 		if err != nil {
 			return nil, err
@@ -94,3 +95,13 @@ var getRsyncVersion = func() (string, error) {
 
 	return versionNumber, nil
 }
+
+func printMessage(RSYNCServer string) {
+	var message strings.Builder
+	message.WriteString("\n\n\n====== Checking for available datasets on archive cache server ")
+	message.WriteString(RSYNCServer)
+	message.WriteString(":\n====== (only datasets highlighted in green will be retrieved)\n\n")
+	message.WriteString("====== If you can not find the dataset in this listing: may be you forgot\n")
+	message.WriteString("====== to start the necessary retrieve job from the the data catalog first?\n\n")
+	fmt.Print(message.String())
+}

datasetUtils/getAvailableDatasets_test.go

@@ -4,6 +4,10 @@ import (
 	"testing"
 	"reflect"
 	"os/exec"
+	"os"
+	"bytes"
+	"io"
+	"strings"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -76,3 +80,31 @@ func TestFormatDatasetId(t *testing.T) {
 		t.Errorf("Expected %s, but got %s", expected, actual)
 	}
 }
+
+func TestPrintMessage(t *testing.T) {
+	RSYNCServer := "testServer"
+
+	expected := "\n\n\n====== Checking for available datasets on archive cache server testServer:\n"
+	expected += "====== (only datasets highlighted in green will be retrieved)\n\n"
+	expected += "====== If you can not find the dataset in this listing: may be you forgot\n"
+	expected += "====== to start the necessary retrieve job from the the data catalog first?\n\n"
+
+	// Redirect standard output to a buffer
+	old := os.Stdout
+	r, w, _ := os.Pipe()
+	os.Stdout = w
+
+	printMessage(RSYNCServer)
+
+	// Restore standard output
+	w.Close()
+	os.Stdout = old
+
+	var buf bytes.Buffer
+	io.Copy(&buf, r)
+	actual := buf.String()
+
+	if !strings.EqualFold(expected, actual) {
+		t.Errorf("Expected %s, but got %s", expected, actual)
+	}
+}