Load execution ID from file

This MR introduces a new class IOHandler that encapsulates the most common I/O operations within the Theodolite framework. In order to do this, this MR also includes some restructuring/refactoring. With this handler, Theodolite uses a file expID.txt to store and load the execution ID for the next experiment.

theodolite-quarkus/src/test/kotlin/theodolite/util/IOHandlerTest.kt

+package theodolite.util
+
+import com.google.gson.GsonBuilder
+import io.quarkus.test.junit.QuarkusTest
+import org.hamcrest.CoreMatchers.containsString
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.Rule
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import org.junit.rules.TemporaryFolder
+import org.junitpioneer.jupiter.ClearEnvironmentVariable
+import org.junitpioneer.jupiter.SetEnvironmentVariable
+
+
+const val FOLDER_URL = "Test-Folder"
+@QuarkusTest
+internal class IOHandlerTest {
+
+    @Rule
+    private var temporaryFolder = TemporaryFolder()
+
+    @Test
+    fun testWriteStringToText() {
+        temporaryFolder.create()
+        val testContent = "Test-File-Content"
+        val folder = temporaryFolder.newFolder(FOLDER_URL)
+
+        IOHandler().writeStringToTextFile(
+            fileURL = "${folder.absolutePath}/test-file.txt",
+            data = testContent)
+
+        assertEquals(
+           testContent,
+            IOHandler().readFileAsString("${folder.absolutePath}/test-file.txt")
+        )
+    }
+
+    @Test
+    fun testWriteToCSVFile() {
+        temporaryFolder.create()
+        val folder = temporaryFolder.newFolder(FOLDER_URL)
+
+        val testContent = listOf(
+            listOf("apples","red"),
+            listOf("bananas","yellow"),
+            listOf("avocado","brown"))
+        val columns = listOf("Fruit", "Color")
+
+        IOHandler().writeToCSVFile(
+            fileURL = "${folder.absolutePath}/test-file",
+            data = testContent,
+            columns = columns)
+
+        var expected = "Fruit,Color\n"
+        testContent.forEach { expected += it[0] + "," +  it[1] + "\n" }
+
+        assertEquals(
+            expected.trim(),
+            IOHandler().readFileAsString("${folder.absolutePath}/test-file.csv")
+        )
+    }
+
+    @Test
+    fun testWriteToJSONFile() {
+        temporaryFolder.create()
+        val folder = temporaryFolder.newFolder(FOLDER_URL)
+        val testContent = Resource(0, emptyList())
+
+        IOHandler().writeToJSONFile(
+            fileURL =  "${folder.absolutePath}/test-file.json",
+            objectToSave = testContent)
+
+        val expected = GsonBuilder().enableComplexMapKeySerialization().setPrettyPrinting().create().toJson(testContent)
+
+        assertEquals(
+            expected,
+            IOHandler().readFileAsString("${folder.absolutePath}/test-file.json")
+        )
+    }
+
+    // Test the function `getResultFolderString`
+
+    @Test
+    @ClearEnvironmentVariable.ClearEnvironmentVariables(
+        ClearEnvironmentVariable(key = "RESULTS_FOLDER"),
+        ClearEnvironmentVariable(key = "CREATE_RESULTS_FOLDER")
+    )
+    fun testGetResultFolderURL_emptyEnvironmentVars() {
+        assertEquals("",IOHandler().getResultFolderURL())
+    }
+
+
+    @Test()
+    @SetEnvironmentVariable.SetEnvironmentVariables(
+        SetEnvironmentVariable(key = "RESULTS_FOLDER", value = "./src/test/resources"),
+        SetEnvironmentVariable(key = "CREATE_RESULTS_FOLDER", value = "false")
+    )
+    fun testGetResultFolderURL_FolderExist() {
+        assertEquals("./src/test/resources/", IOHandler().getResultFolderURL())
+    }
+
+    @Test()
+    @SetEnvironmentVariable.SetEnvironmentVariables(
+        SetEnvironmentVariable(key = "RESULTS_FOLDER", value = "$FOLDER_URL-0"),
+        SetEnvironmentVariable(key = "CREATE_RESULTS_FOLDER", value = "false")
+    )
+    fun testGetResultFolderURL_FolderNotExist() {
+        var exceptionWasThrown = false
+        try {
+            IOHandler().getResultFolderURL()
+          } catch (e: Exception){
+              exceptionWasThrown = true
+              assertThat(e.toString(), containsString("Result folder not found"));
+          }
+        assertTrue(exceptionWasThrown)
+    }
+
+    @Test()
+    @SetEnvironmentVariable.SetEnvironmentVariables(
+        SetEnvironmentVariable(key = "RESULTS_FOLDER", value = FOLDER_URL),
+        SetEnvironmentVariable(key = "CREATE_RESULTS_FOLDER", value = "true")
+    )
+    fun testGetResultFolderURL_CreateFolderIfNotExist() {
+        assertEquals("$FOLDER_URL/",  IOHandler().getResultFolderURL())
+    }
+
+    @Test()
+    @ClearEnvironmentVariable(key = "RESULTS_FOLDER" )
+    @SetEnvironmentVariable(key = "CREATE_RESULTS_FOLDER", value = "true")
+    fun testGetResultFolderURL_CreateFolderButNoFolderGiven() {
+        assertEquals("",  IOHandler().getResultFolderURL())
+    }
+}