fix:#40 added test for remove empty courses and fix bug in function

backend/service/events/courseService_test.go

@@ -0,0 +1,39 @@
+package events
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_removeEmptyCourses(t *testing.T) {
+	type args struct {
+		courses []string
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			name: "Test remove empty courses",
+			args: args{
+				courses: []string{"", "test", "test2", ""},
+			},
+			want: []string{"test", "test2"},
+		},
+		{
+			name: "Test remove empty courses",
+			args: args{
+				courses: []string{"", "test", "test2", "", "test3"},
+			},
+			want: []string{"test", "test2", "test3"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := removeEmptyCourses(tt.args.courses); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("removeEmptyCourses() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}