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

tests/Paca.Tests/Core/QuickActionsExtremeRedTests.cs

@@ -0,0 +1,124 @@
+using System;
+using System.Text;
+using System.Threading.Tasks;
+using Paca.Core.QuickActions;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+public class QuickActionsExtremeRedTests
+{
+    // ==========================================
+    // 1. QuickActionFuzzyMatcher Memory & DoS
+    // ==========================================
+
+    [Fact]
+    public void QuickActionFuzzyMatcher_LevenshteinDistance_LargeStrings_DoesNotThrowOutOfMemory()
+    {
+        // 5000 character strings would allocate ~100MB in 2D array if unbounded
+        string large1 = new string('A', 3000);
+        string large2 = new string('B', 3000);
+
+        var ex = Record.Exception(() => QuickActionFuzzyMatcher.LevenshteinDistance(large1, large2));
+        Assert.Null(ex);
+    }
+
+    [Theory]
+    [InlineData(null, null)]
+    [InlineData(null, "abc")]
+    [InlineData("xyz", null)]
+    public void QuickActionFuzzyMatcher_LevenshteinDistance_Nulls_HandledGracefully(string? s, string? t)
+    {
+        var ex = Record.Exception(() => QuickActionFuzzyMatcher.LevenshteinDistance(s, t));
+        Assert.Null(ex);
+    }
+
+    // ==========================================
+    // 2. QuickActionInlineEvaluator Hardening
+    // ==========================================
+
+    [Theory]
+    [InlineData("-5 + 10", "5")]
+    [InlineData("10 * -2", "-20")]
+    [InlineData("-4 * -3", "12")]
+    public void QuickActionInlineEvaluator_TryEvaluateMath_NegativeNumbers_CalculatesCorrectly(string expr, string expected)
+    {
+        var eval = new QuickActionInlineEvaluator();
+        bool success = eval.TryEvaluate(expr, out var res);
+        Assert.True(success, $"Expression '{expr}' should be successfully evaluated");
+        Assert.NotNull(res);
+        Assert.Equal(expected, res.Value);
+    }
+
+    [Theory]
+    [InlineData("#fff", "rgb(255, 255, 255)")]
+    [InlineData("#F00", "rgb(255, 0, 0)")]
+    [InlineData("hex 000", "rgb(0, 0, 0)")]
+    public void QuickActionInlineEvaluator_TryEvaluateDev_Hex3DigitShorthand_ExpandsCorrectly(string hexInput, string expectedRgb)
+    {
+        var eval = new QuickActionInlineEvaluator();
+        bool success = eval.TryEvaluate(hexInput, out var res);
+        Assert.True(success, $"Shorthand hex '{hexInput}' should be parsed");
+        Assert.NotNull(res);
+        Assert.Equal(expectedRgb, res.Value);
+    }
+
+    [Fact]
+    public void QuickActionInlineEvaluator_TryEvaluateDev_Base64WithNullBytes_DoesNotReturnRawNullChars()
+    {
+        var eval = new QuickActionInlineEvaluator();
+        // Base64 containing null bytes: "\0\0\0" -> "AAAA"
+        bool success = eval.TryEvaluate("b64d AAAA", out var res);
+        Assert.True(success);
+        Assert.NotNull(res);
+        Assert.DoesNotContain('\0', res.Value);
+    }
+
+    // ==========================================
+    // 3. QuickActionClipboardDetector Security & Resilience
+    // ==========================================
+
+    [Fact]
+    public void QuickActionClipboardDetector_DetectIntent_EnormousClipboard_DoesNotSpikeOrHang()
+    {
+        var detector = new QuickActionClipboardDetector();
+        string hugeText = new string('x', 500_000); // 500KB
+
+        var intent = detector.DetectIntent(hugeText);
+        Assert.NotNull(intent);
+        Assert.Equal(ClipboardIntentType.None, intent.IntentType);
+    }
+
+    [Theory]
+    [InlineData("youtube.com/watch?v=dQw4w9WgXcQ")]
+    [InlineData("www.youtube.com/watch?v=dQw4w9WgXcQ")]
+    [InlineData("youtu.be/dQw4w9WgXcQ")]
+    public void QuickActionClipboardDetector_DetectIntent_MediaUrlWithoutScheme_DetectedAsMediaDownload(string rawUrl)
+    {
+        var detector = new QuickActionClipboardDetector();
+        var intent = detector.DetectIntent(rawUrl);
+        Assert.NotNull(intent);
+        Assert.Equal(ClipboardIntentType.MediaDownload, intent.IntentType);
+    }
+
+    // ==========================================
+    // 4. QuickActionParameterRouter Null Context Defenses
+    // ==========================================
+
+    [Theory]
+    [InlineData("b64 hello")]
+    [InlineData("b64d aGVsbG8=")]
+    [InlineData("hash password123")]
+    [InlineData("note sample note")]
+    public async Task QuickActionParameterRouter_Handlers_NullContext_DoesNotThrowNullReferenceException(string command)
+    {
+        var router = new QuickActionParameterRouter();
+        bool parsed = router.TryParseCommand(command, out var action);
+        Assert.True(parsed);
+        Assert.NotNull(action);
+
+        var ex = await Record.ExceptionAsync(async () => await action!.Handler!(null!));
+        Assert.Null(ex);
+    }
+}
+