diff --git a/build.sbt b/build.sbt
index 85adeea..2cbeb3d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -28,4 +28,7 @@ libraryDependencies ++= Seq(
   "io.circe" %% "circe-generic-extras" % circeVersion,
   "io.circe" %% "circe-optics" % circeVersion,
   "io.circe" %% "circe-parser" % circeVersion,
+
+  "org.scalatest" %% "scalatest" % "3.2.16" % Test,
+  "org.scalamock" %% "scalamock" % "5.2.0" % Test
 )
diff --git a/src/test/scala/fetch/FileNameServiceSpec.scala b/src/test/scala/fetch/FileNameServiceSpec.scala
new file mode 100644
index 0000000..67a8fba
--- /dev/null
+++ b/src/test/scala/fetch/FileNameServiceSpec.scala
@@ -0,0 +1,35 @@
+import fetch.FileNameService
+import org.scalatest.funsuite.AnyFunSuite
+
+import java.time.LocalDateTime
+
+class FileNameServiceSpec extends AnyFunSuite {
+
+  test("FileNameService.generate returns correct file names") {
+    val startTime = LocalDateTime.of(2023, 5, 17, 0, 0)
+    val endTime = LocalDateTime.of(2023, 5, 17, 4, 0)
+
+    val expectedFileNames = List(
+      "20230517_0030.csv",
+      "20230517_0130.csv",
+      "20230517_0230.csv",
+      "20230517_0330.csv",
+    )
+
+    val actualFileNames = FileNameService.generate(startTime, endTime)
+
+    assert(actualFileNames == expectedFileNames)
+  }
+
+  test("FileNameService.generateFromDate returns correct file names") {
+    val date = LocalDateTime.of(2023, 5, 17, 0, 0).toLocalDate
+
+    val expectedFileNames = (0 to 23).toList
+      .map(hour => if(hour < 10) "0"+hour else ""+hour)
+      .map(str => s"20230517_${str}30.csv")
+
+    val actualFileNames = FileNameService.generateFromDate(date)
+
+    assert(actualFileNames == expectedFileNames)
+  }
+}
\ No newline at end of file
diff --git a/src/test/scala/utils/IOSuite.scala b/src/test/scala/utils/IOSuite.scala
new file mode 100644
index 0000000..d162fc2
--- /dev/null
+++ b/src/test/scala/utils/IOSuite.scala
@@ -0,0 +1,18 @@
+package base
+
+import cats.effect.IO
+import cats.effect.unsafe.IORuntime
+import org.scalatest.Succeeded
+
+import scala.concurrent.Future
+import scala.concurrent.duration._
+
+trait IOSuite {
+
+  val Timeout: FiniteDuration = 5.seconds
+
+  implicit val ioRuntime: IORuntime = IORuntime.global
+
+  def runIO[A](io: IO[A], timeout: FiniteDuration = Timeout): Future[Succeeded.type] =
+    io.timeout(timeout).as(Succeeded).unsafeToFuture()
+}
\ No newline at end of file