feat: state manager singleton

EasyLib/Files/StateManager.cs

@@ -0,0 +1,31 @@
+namespace EasyLib.Files;
+
+/// <summary>
+/// Singleton to get and write the jobs to the state.json file.
+/// </summary>
+public class StateManager
+{
+    public readonly string StateFilePath;
+
+    private StateManager()
+    {
+        // AppData dir and append easysave/state.json
+        var appDataDir = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
+        var stateDirectory = Path.Combine(appDataDir, "easysave");
+        StateFilePath = Path.Combine(stateDirectory, "state.json");
+
+        // Create directory if it doesn't exist
+        if (!Directory.Exists(stateDirectory))
+        {
+            Directory.CreateDirectory(stateDirectory);
+        }
+
+        // Create file and write [] if it doesn't exist
+        if (!File.Exists(StateFilePath))
+        {
+            File.WriteAllText(StateFilePath, "[]");
+        }
+    }
+
+    public static StateManager Instance { get; } = new();
+}

EasySave.Tests/EasyLib/Files/StateManagerTests.cs

@@ -0,0 +1,67 @@
+using EasyLib.Files;
+
+namespace EasySave.Tests.EasyLib.Files;
+
+public class StateManagerTests
+{
+    private string GetStateFilePath()
+    {
+        var appDataDir = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
+        var stateDirectory = Path.Combine(appDataDir, "easysave");
+        return Path.Combine(stateDirectory, "state.json");
+    }
+
+    [Fact]
+    public void Instance_ShouldBeSingleton()
+    {
+        // Arrange
+
+        // Act
+        var instance1 = StateManager.Instance;
+        var instance2 = StateManager.Instance;
+
+        // Assert
+        Assert.Same(instance1, instance2);
+    }
+
+    [Fact]
+    public void StateFileCreation_ShouldCreateEmptyFile()
+    {
+        // Arrange
+
+        // Act
+        var stateManager = StateManager.Instance;
+        var stateFilePath = stateManager.StateFilePath;
+
+        // Assert
+        Assert.True(File.Exists(stateFilePath));
+    }
+
+    [Fact]
+    public void StateFileCreation_ShouldCreateJsonArray()
+    {
+        // Arrange
+
+        // Act
+        var stateManager = StateManager.Instance;
+        var stateFilePath = stateManager.StateFilePath;
+        var fileContent = File.ReadAllText(stateFilePath).Trim();
+
+        // Assert
+        Assert.StartsWith("[", fileContent);
+        Assert.EndsWith("]", fileContent);
+    }
+
+    [Fact]
+    public void StateFilePath_ShouldBeCorrect()
+    {
+        // Arrange
+
+        // Act
+        var stateManager = StateManager.Instance;
+        var stateFilePath = stateManager.StateFilePath;
+
+        // Assert
+        Assert.Equal(GetStateFilePath(), stateFilePath);
+    }
+}