test(core/browser/platform): 26 extreme RED/GREEN TDD cycles and full regression hardening (3,235 PASS)

tests/Paca.Tests/Core/SocialSiteDetectorExtremeRedTests.cs

@@ -0,0 +1,71 @@
+using System;
+using Paca.Core.Detection;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+/// <summary>
+/// Cycle 6: 극한 RED 시나리오 - 소셜 사이트 감지기의 상대 URI 크래시, 비-HTTP 스킴, 변칙/불완전 URL 방어선 검증
+/// </summary>
+public class SocialSiteDetectorExtremeRedTests
+{
+    [Fact]
+    public void Cycle6_Gate1_RelativeUri_MustNotThrowInvalidOperationException()
+    {
+        // 브라우저 탭 주소나 페이지 내 상대 링크에서 상대 URI가 유입될 때
+        // url.Host 접근으로 인한 InvalidOperationException 크래시 방지
+        var relUri1 = new Uri("/watch?v=dQw4w9WgXcQ", UriKind.Relative);
+        var relUri2 = new Uri("shorts/dQw4w9WgXcQ", UriKind.Relative);
+        var relUri3 = new Uri("media.mp4", UriKind.Relative);
+
+        bool matched1 = SocialSiteDetector.TryMatch(relUri1, out _, out _);
+        Assert.False(matched1);
+
+        bool matched2 = SocialSiteDetector.TryMatch(relUri2, out _, out _);
+        Assert.False(matched2);
+
+        bool matched3 = SocialSiteDetector.TryMatch(relUri3, out _, out _);
+        Assert.False(matched3);
+    }
+
+    [Theory]
+    [InlineData("data:text/html,<html>test</html>")]
+    [InlineData("javascript:alert(1)")]
+    [InlineData("file:///C:/videos/test.mp4")]
+    [InlineData("about:blank")]
+    public void Cycle6_Gate2_NonHttpSchemes_MustReturnFalseSafely(string uriString)
+    {
+        var uri = new Uri(uriString);
+        bool matched = SocialSiteDetector.TryMatch(uri, out _, out _);
+        Assert.False(matched);
+    }
+
+    [Theory]
+    [InlineData("https://www.youtube.com/watch?v=short")]
+    [InlineData("https://www.youtube.com/watch?v=waytoolongid1234567890")]
+    [InlineData("https://www.youtube.com/watch?v=invalid@id!")]
+    [InlineData("https://www.youtube.com/watch?v=")]
+    [InlineData("https://www.youtube.com/watch")]
+    [InlineData("https://www.youtube.com/channel/UC123456")]
+    [InlineData("https://www.youtube.com/user/pewdiepie")]
+    public void Cycle6_Gate3_YouTubeIdBoundaryFuzzing_MustRejectInvalidUrls(string urlString)
+    {
+        var uri = new Uri(urlString);
+        bool matched = SocialSiteDetector.TryMatch(uri, out _, out _);
+        Assert.False(matched);
+    }
+
+    [Theory]
+    [InlineData("https://www.instagram.com/p/")]
+    [InlineData("https://www.instagram.com/reel/")]
+    [InlineData("https://www.tiktok.com/@someuser")]
+    [InlineData("https://www.tiktok.com/")]
+    [InlineData("https://www.facebook.com/watch/")]
+    [InlineData("https://www.facebook.com/reel/")]
+    public void Cycle6_Gate4_InstagramAndTikTok_MalformedPaths_MustReject(string urlString)
+    {
+        var uri = new Uri(urlString);
+        bool matched = SocialSiteDetector.TryMatch(uri, out _, out _);
+        Assert.False(matched);
+    }
+}