From f8645802077f8dd9c5e60995cad0602188ec3cde Mon Sep 17 00:00:00 2001
From: Antigravity <antigravity@google.com>
Date: Mon, 11 May 2026 18:09:07 +0000
Subject: [PATCH] test: add unit tests for EpubMetadataExtractor robustness

---
 .../Services/EpubMetadataExtractorTests.cs    | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 tests/NexusReader.Application.Tests/Services/EpubMetadataExtractorTests.cs

diff --git a/tests/NexusReader.Application.Tests/Services/EpubMetadataExtractorTests.cs b/tests/NexusReader.Application.Tests/Services/EpubMetadataExtractorTests.cs
new file mode 100644
index 0000000..6b25ba5
--- /dev/null
+++ b/tests/NexusReader.Application.Tests/Services/EpubMetadataExtractorTests.cs
@@ -0,0 +1,28 @@
+using NexusReader.Infrastructure.Services;
+using Xunit;
+
+namespace NexusReader.Application.Tests.Services;
+
+public class EpubMetadataExtractorTests
+{
+    private readonly EpubMetadataExtractor _sut;
+
+    public EpubMetadataExtractorTests()
+    {
+        _sut = new EpubMetadataExtractor();
+    }
+
+    [Fact]
+    public async Task ExtractMetadataAsync_WithInvalidStream_ReturnsFailure()
+    {
+        // Arrange
+        using var invalidStream = new MemoryStream(new byte[] { 0, 1, 2, 3 });
+
+        // Act
+        var result = await _sut.ExtractMetadataAsync(invalidStream);
+
+        // Assert
+        Assert.True(result.IsFailed);
+        Assert.Contains("Failed to extract EPUB metadata", result.Errors[0].Message);
+    }
+}