feat: add rename format registry

SongTidy.Tests/RenameFormatsTests.cs

@@ -0,0 +1,146 @@
+using SongTidy.Models;
+
+namespace SongTidy.Tests;
+
+/// <summary>
+/// Contains tests for <see cref="RenameFormats"/>.
+/// </summary>
+[TestClass]
+public sealed class RenameFormatsTests {
+    #region Artist-first format
+
+    /// <summary>
+    /// Verifies the artist-first layout when both optional fields are present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesArtistFirstWithArtistAndComment() {
+        AssertStem(RenameFormat.ArtistFirst, "Artist", "Title", "Live", "Artist - Title (Live)");
+    }
+
+    /// <summary>
+    /// Verifies the artist-first layout when only the artist is present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesArtistFirstWithArtistOnly() {
+        AssertStem(RenameFormat.ArtistFirst, "Artist", "Title", string.Empty, "Artist - Title");
+    }
+
+    /// <summary>
+    /// Verifies the artist-first layout when only the comment is present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesArtistFirstWithCommentOnly() {
+        AssertStem(RenameFormat.ArtistFirst, string.Empty, "Title", "Live", "Title (Live)");
+    }
+
+    /// <summary>
+    /// Verifies the artist-first layout when neither optional field is present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesArtistFirstWithTitleOnly() {
+        AssertStem(RenameFormat.ArtistFirst, string.Empty, "Title", string.Empty, "Title");
+    }
+
+    #endregion
+
+    #region Title-first format
+
+    /// <summary>
+    /// Verifies the title-first layout when both optional fields are present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesTitleFirstWithArtistAndComment() {
+        AssertStem(RenameFormat.TitleFirst, "Artist", "Title", "Live", "Title (Live) - Artist");
+    }
+
+    /// <summary>
+    /// Verifies the title-first layout when only the artist is present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesTitleFirstWithArtistOnly() {
+        AssertStem(RenameFormat.TitleFirst, "Artist", "Title", string.Empty, "Title - Artist");
+    }
+
+    /// <summary>
+    /// Verifies the title-first layout when only the comment is present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesTitleFirstWithCommentOnly() {
+        AssertStem(RenameFormat.TitleFirst, string.Empty, "Title", "Live", "Title (Live)");
+    }
+
+    /// <summary>
+    /// Verifies the title-first layout when neither optional field is present.
+    /// </summary>
+    [TestMethod]
+    public void GeneratesTitleFirstWithTitleOnly() {
+        AssertStem(RenameFormat.TitleFirst, string.Empty, "Title", string.Empty, "Title");
+    }
+
+    #endregion
+
+    #region Registry
+
+    /// <summary>
+    /// Verifies that every enum member has a registered format definition.
+    /// </summary>
+    [TestMethod]
+    public void RegistersEveryFormat() {
+        foreach (RenameFormat format in Enum.GetValues<RenameFormat>()) {
+            Assert.IsTrue(
+                RenameFormats.Definitions.ContainsKey(format),
+                $"Missing definition for {format}.");
+        }
+    }
+
+    /// <summary>
+    /// Verifies that an unregistered enum value is rejected.
+    /// </summary>
+    [TestMethod]
+    public void ThrowsForUnregisteredFormat() {
+        Assert.Throws<ArgumentOutOfRangeException>(
+            () => RenameFormats.GenerateStem((RenameFormat)999, "Artist", "Title", "Live"));
+    }
+
+    #endregion
+
+    #region Edge cases
+
+    /// <summary>
+    /// Verifies that whitespace-only optional fields are treated as missing.
+    /// </summary>
+    [TestMethod]
+    public void TreatsWhitespaceOnlyOptionalFieldsAsMissing() {
+        AssertStem(RenameFormat.ArtistFirst, "   ", "Title", "\t", "Title");
+    }
+
+    /// <summary>
+    /// Verifies that a null title is rejected.
+    /// </summary>
+    [TestMethod]
+    public void ThrowsForNullTitle() {
+        Assert.Throws<ArgumentNullException>(
+            () => RenameFormats.GenerateStem(RenameFormat.ArtistFirst, "Artist", null!, "Live"));
+    }
+
+    #endregion
+
+    /// <summary>
+    /// Generates a file name stem and asserts the result.
+    /// </summary>
+    /// <param name="format">The format to apply.</param>
+    /// <param name="artist">The artist value.</param>
+    /// <param name="title">The title value.</param>
+    /// <param name="comment">The comment value.</param>
+    /// <param name="expected">The expected generated stem.</param>
+    private static void AssertStem(
+        RenameFormat format,
+        string artist,
+        string title,
+        string comment,
+        string expected) {
+        string actual = RenameFormats.GenerateStem(format, artist, title, comment);
+
+        Assert.AreEqual(expected, actual, $"Unexpected stem for {format}.");
+    }
+}