DesktopModelSaver saves file

composeApp/src/desktopMain/kotlin/state/DesktopModelSaver.kt

@@ -0,0 +1,11 @@
+package state
+
+import resources.AppFile
+import viewmodel.DewItViewModel
+
+class DesktopModelSaver(private val fileName: String, private val model: DewItViewModel) : ModelSaver {
+    override fun save() {
+        val appFile = AppFile(fileName)
+        appFile.writeText(model.toJson())
+    }
+}

composeApp/src/desktopTest/kotlin/state/DesktopModelSaverTest.kt

@@ -0,0 +1,33 @@
+package state
+
+import io.kotest.matchers.booleans.shouldBeFalse
+import io.kotest.matchers.booleans.shouldBeTrue
+import resources.AppFile
+import viewmodel.GtdModel
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+
+const val fileName = "testSave.json"
+
+class DesktopModelSaverTest {
+    val saveFile = AppFile(fileName)
+    val model = GtdModel.createModel()
+
+    @BeforeTest
+    fun setup() {
+        if(saveFile.exists()) {
+            saveFile.delete()
+        }
+    }
+
+    @Test
+    fun androidModelSaverCreatesASaveFile() {
+        val modelSaver: ModelSaver = DesktopModelSaver(fileName, model)
+
+        saveFile.exists().shouldBeFalse()
+
+        modelSaver.save()
+
+        saveFile.exists().shouldBeTrue()
+    }
+}