Merge branch 'main' into Add-more-TempFile-create-APIs

Author: SimonCropp

src/Directory.Packages.props

@@ -22,7 +22,7 @@
     <PackageVersion Include="MSTest" Version="4.0.2" />
     <PackageVersion Include="MSTest.TestFramework" Version="4.0.2" />
     <PackageVersion Include="NUnit3TestAdapter" Version="5.2.0" />
-    <PackageVersion Include="Polyfill" Version="9.3.0" />
+    <PackageVersion Include="Polyfill" Version="9.3.1" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.163" />
     <PackageVersion Include="PublicApiGenerator" Version="11.5.3" />
     <PackageVersion Include="SimpleInfoName" Version="3.1.2" />

src/Verify.Tests/LinesScrubberTests.cs

@@ -77,4 +77,239 @@ public Task ScrubLinesContaining_case_sensitive()
                     f
                     """);
     }
+
+    [Fact]
+    public void FilterLines_RemovesSingleLine()
+    {
+        var builder = new StringBuilder("line1\nline2\nline3");
+
+        builder.FilterLines(line => line == "line2");
+
+        Assert.Equal("line1\nline3", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_RemovesMultipleLines()
+    {
+        var builder = new StringBuilder("keep1\nremove1\nkeep2\nremove2\nkeep3");
+
+        builder.FilterLines(line => line.StartsWith("remove"));
+
+        Assert.Equal("keep1\nkeep2\nkeep3", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_RemovesAllLines()
+    {
+        var builder = new StringBuilder("line1\nline2\nline3");
+
+        builder.FilterLines(_ => true);
+
+        Assert.Equal(string.Empty, builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_RemovesNoLines()
+    {
+        var builder = new StringBuilder("line1\nline2\nline3");
+        var original = builder.ToString();
+
+        builder.FilterLines(_ => false);
+
+        Assert.Equal(original, builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_EmptyStringBuilder()
+    {
+        var builder = new StringBuilder();
+
+        builder.FilterLines(_ => true);
+
+        Assert.Equal(string.Empty, builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_SingleLineNoNewline()
+    {
+        var builder = new StringBuilder("single line");
+
+        builder.FilterLines(_ => false);
+
+        Assert.Equal("single line", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_SingleLineWithNewline()
+    {
+        var builder = new StringBuilder("single line\n");
+
+        builder.FilterLines(_ => false);
+
+        Assert.Equal("single line\n", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_PreservesTrailingNewline()
+    {
+        var builder = new StringBuilder("line1\nline2\n");
+
+        builder.FilterLines(line => line == "line2");
+
+        Assert.Equal("line1\n", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_DoesNotAddTrailingNewlineWhenOriginalLacked()
+    {
+        var builder = new StringBuilder("line1\nline2");
+
+        builder.FilterLines(line => line == "line1");
+
+        Assert.Equal("line2", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_HandlesEmptyLines()
+    {
+        var builder = new StringBuilder("line1\n\nline3");
+
+        builder.FilterLines(string.IsNullOrEmpty);
+
+        Assert.Equal("line1\nline3", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_KeepsEmptyLines()
+    {
+        var builder = new StringBuilder("line1\n\nline3");
+
+        builder.FilterLines(line => line == "line1");
+
+        Assert.Equal("\nline3", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_OnlyEmptyLines()
+    {
+        var builder = new StringBuilder("\n\n");
+
+        builder.FilterLines(_ => false);
+
+        Assert.Equal("\n\n", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_RemovesFirstLine()
+    {
+        var builder = new StringBuilder("remove\nkeep1\nkeep2");
+
+        builder.FilterLines(line => line == "remove");
+
+        Assert.Equal("keep1\nkeep2", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_RemovesLastLine()
+    {
+        var builder = new StringBuilder("keep1\nkeep2\nremove");
+
+        builder.FilterLines(line => line == "remove");
+
+        Assert.Equal("keep1\nkeep2", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_RemovesLastLineWithTrailingNewline()
+    {
+        var builder = new StringBuilder("keep1\nkeep2\nremove\n");
+
+        builder.FilterLines(line => line == "remove");
+
+        Assert.Equal("keep1\nkeep2\n", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_ComplexPredicate()
+    {
+        var builder = new StringBuilder("abc123\ndef456\nghi789\njkl012");
+
+        builder.FilterLines(line => line.Any(char.IsDigit) && line.Contains('4'));
+
+        Assert.Equal("abc123\nghi789\njkl012", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_WindowsLineEndings()
+    {
+        var builder = new StringBuilder("line1\r\nline2\r\nline3");
+
+        builder.FilterLines(line => line == "line2");
+
+        // Note: StringReader normalizes \r\n to \n
+        Assert.Equal("line1\nline3", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_MixedLineEndings()
+    {
+        var builder = new StringBuilder("line1\nline2\r\nline3");
+
+        builder.FilterLines(line => line == "line2");
+
+        Assert.Equal("line1\nline3", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_LargeContent()
+    {
+        var lines = Enumerable.Range(1, 1000).Select(i => $"line{i}");
+        var builder = new StringBuilder(string.Join('\n', lines));
+
+        builder.FilterLines(line => int.Parse(line[4..]) % 2 == 0);
+
+        var remaining = builder.ToString().Split('\n');
+        Assert.Equal(500, remaining.Length);
+        Assert.All(remaining, line => Assert.True(int.Parse(line[4..]) % 2 == 1));
+    }
+
+    [Fact]
+    public void FilterLines_PreservesWhitespace()
+    {
+        var builder = new StringBuilder("  line1  \n\t line2\t\nline3   ");
+
+        builder.FilterLines(line => line.Trim() == "line2");
+
+        Assert.Equal("  line1  \nline3   ", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_SingleLineRemoved()
+    {
+        var builder = new StringBuilder("remove this");
+
+        builder.FilterLines(_ => true);
+
+        Assert.Equal(string.Empty, builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_AllButLastRemoved()
+    {
+        var builder = new StringBuilder("remove1\nremove2\nkeep\n");
+
+        builder.FilterLines(line => line.StartsWith("remove"));
+
+        Assert.Equal("keep\n", builder.ToString());
+    }
+
+    [Fact]
+    public void FilterLines_MultipleConsecutiveRemoved()
+    {
+        var builder = new StringBuilder("keep1\nremove1\nremove2\nremove3\nkeep2");
+
+        builder.FilterLines(line => line.StartsWith("remove"));
+
+        Assert.Equal("keep1\nkeep2", builder.ToString());
+    }
 }