Reject carriage returns in verified files instead of normalizing (#1762)

* Reject carriage returns in verified files instead of normalizing

The text comparison previously read the verified file via
ReadStringBuilderWithFixedLines, silently converting \r\n and \r to \n.
Now it reads the file directly and throws if it contains a \r, linking
to the text-file-settings docs. Verified files are LF-only (enforced by
.gitattributes), so this surfaces misconfigured line endings rather than
masking them.

Author: SimonCropp

src/Directory.Build.props

@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CA1822;CS1591;CS0649;xUnit1026;xUnit1013;CS1573;VerifyTestsProjectDir;VerifySetParameters;PolyFillTargetsForNuget;xUnit1051;NU1608;NU1109</NoWarn>
-    <Version>31.20.0</Version>
+    <Version>31.21.0</Version>
     <ImplicitUsings>enable</ImplicitUsings>
     <LangVersion>preview</LangVersion>
     <AssemblyVersion>1.0.0</AssemblyVersion>

src/StrictJsonTests/SerializationTests.ImmutableArray_Empty.verified.json

@@ -1,3 +1,3 @@
 {
   "Array": null
-}
+}

src/StrictJsonTests/SerializationTests.ImmutableArray_Uninitialized.verified.json

@@ -1,3 +1,3 @@
 {
   "Array": null
-}
+}

src/Verify.ExceptionParsing.Tests/ExceptionMessageFormatSamples.cs

@@ -14,7 +14,7 @@ public Task AllCategories()
         };
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", Dir("MyTests.Test2.received.txt"), Dir("MyTests.Test2.verified.txt")), null, new("received text"), new("verified text"))
+            new(new("txt", Dir("MyTests.Test2.received.txt"), Dir("MyTests.Test2.verified.txt")), null, new("received text"), "verified text")
         };
         var delete = new List<string>
         {
@@ -33,7 +33,7 @@ public Task NotEqualWithMessage()
     {
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", Dir("MyTests.Test1.received.txt"), Dir("MyTests.Test1.verified.txt")), "The comparer reported a difference", new("received text"), new("verified text"))
+            new(new("txt", Dir("MyTests.Test1.received.txt"), Dir("MyTests.Test1.verified.txt")), "The comparer reported a difference", new("received text"), "verified text")
         };
 
         return BuildVerify([], notEquals, [], []);

src/Verify.ExceptionParsing.Tests/ExceptionParsingTests.cs

@@ -31,7 +31,7 @@ public Task WithMessage()
     {
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", receivedTxt, verifiedTxt), "TheMessage", new("receivedText"), new("verifiedText")),
+            new(new("txt", receivedTxt, verifiedTxt), "TheMessage", new("receivedText"), "verifiedText"),
             new(new("bin", receivedBin, verifiedBin), "TheMessage", null, null)
         };
 
@@ -132,7 +132,7 @@ public Task SingleNotEqual()
     {
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", receivedTxt, verifiedTxt), null, new("receivedText"), new("verifiedText"))
+            new(new("txt", receivedTxt, verifiedTxt), null, new("receivedText"), "verifiedText")
         };
 
         return ParseVerify([], notEquals, [], []);
@@ -153,7 +153,7 @@ public Task MultipleItem()
         };
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", receivedTxt, verifiedTxt), null, new("receivedText"), new("verifiedText")),
+            new(new("txt", receivedTxt, verifiedTxt), null, new("receivedText"), "verifiedText"),
             new(new("bin", receivedBin, verifiedBin), null, null, null)
         };
         var delete = new List<string>
@@ -178,7 +178,7 @@ public Task SingleItem()
         };
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", receivedTxt, verifiedTxt), null, new("receivedText"), new("verifiedText"))
+            new(new("txt", receivedTxt, verifiedTxt), null, new("receivedText"), "verifiedText")
         };
         var delete = new List<string>
         {
@@ -242,4 +242,4 @@ static Task ParseVerify(
                 result
             });
     }
-}
+}

src/Verify.ExceptionParsing.Tests/VerifyExceptionMessageBuilderTests.cs

@@ -42,7 +42,7 @@ public Task SingleNotEqual_Text() =>
             @new: [],
             notEquals:
             [
-                new(new("txt", receivedTxt, verifiedTxt), null, new("received content"), new("verified content"))
+                new(new("txt", receivedTxt, verifiedTxt), null, new("received content"), "verified content")
             ],
             delete: [],
             equal: []);
@@ -53,7 +53,7 @@ public Task SingleNotEqual_WithMessage() =>
             @new: [],
             notEquals:
             [
-                new(new("txt", receivedTxt, verifiedTxt), "Comparer reported difference", new("received content"), new("verified content"))
+                new(new("txt", receivedTxt, verifiedTxt), "Comparer reported difference", new("received content"), "verified content")
             ],
             delete: [],
             equal: []);
@@ -108,7 +108,7 @@ public Task AllCategories()
         };
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", receivedTxt, verifiedTxt), null, new("received"), new("verified"))
+            new(new("txt", receivedTxt, verifiedTxt), null, new("received"), "verified")
         };
         var delete = new List<string>
         {
@@ -139,8 +139,8 @@ public Task MultipleNotEqual_MixedMessageAndNoMessage()
     {
         var notEquals = new List<NotEqualResult>
         {
-            new(new("txt", receivedTxt, verifiedTxt), null, new("received text"), new("verified text")),
-            new(new("txt", receivedTxt, verifiedTxt), "Custom comparison message", new("received2"), new("verified2"))
+            new(new("txt", receivedTxt, verifiedTxt), null, new("received text"), "verified text"),
+            new(new("txt", receivedTxt, verifiedTxt), "Custom comparison message", new("received2"), "verified2")
         };
 
         return BuildVerify([], notEquals, [], []);

src/Verify.MSTest.SourceGenerator.Tests/NoMatchTests.NoAttributes.verified.txt

@@ -1 +1 @@
-{}
+{}

src/Verify.Tests/NewLineTests.cs

@@ -44,35 +44,27 @@ public async Task StringWithDifferingNewline()
     {
         var fullPath = CurrentFile.Relative("NewLineTests.StringWithDifferingNewline.verified.txt");
         File.Delete(fullPath);
+        var settings = new VerifySettings();
+        settings.DisableRequireUniquePrefix();
+
+        // A verified file containing \r is rejected rather than silently normalized
         await File.WriteAllTextAsync(fullPath, "a\r\nb");
-        await Verify("a\r\nb");
-        PrefixUnique.Clear();
-        await Verify("a\rb");
-        PrefixUnique.Clear();
-        await Verify("a\nb");
-        PrefixUnique.Clear();
+        var crlf = await Assert.ThrowsAnyAsync<Exception>(() => Verify("a\nb", settings));
+        Assert.Contains("carriage return", crlf.ToString());
 
-        File.Delete(fullPath);
+        await File.WriteAllTextAsync(fullPath, "a\rb");
+        var cr = await Assert.ThrowsAnyAsync<Exception>(() => Verify("a\nb", settings));
+        Assert.Contains("carriage return", cr.ToString());
+
+        // A verified file using \n still matches received content normalized to \n
         await File.WriteAllTextAsync(fullPath, "a\nb");
-        await Verify("a\r\nb");
-        PrefixUnique.Clear();
-        await Verify("a\rb");
-        PrefixUnique.Clear();
-        await Verify("a\nb");
-        PrefixUnique.Clear();
+        await Verify("a\r\nb", settings);
+        await Verify("a\rb", settings);
+        await Verify("a\nb", settings);
 
         File.Delete(fullPath);
-        await File.WriteAllTextAsync(fullPath, "a\rb");
-        await Verify("a\r\nb");
-        PrefixUnique.Clear();
-        await Verify("a\rb");
-        PrefixUnique.Clear();
-        await Verify("a\nb");
-        File.Delete(fullPath);
     }
 
-#if NET9_0
-
     [Fact]
     public async Task TrailingNewlinesRaw()
     {
@@ -81,26 +73,21 @@ public async Task TrailingNewlinesRaw()
         var settings = new VerifySettings();
         settings.DisableRequireUniquePrefix();
 
+        // A verified file containing \r is rejected
         await File.WriteAllTextAsync(file, "a\r\n");
-        await Verify("a\r\n", settings);
-        await Verify("a\n", settings);
-        await Verify("a", settings);
-
-        await File.WriteAllTextAsync(file, "a\r\n\r\n");
-        await Verify("a\r\n\r\n", settings);
-        await Verify("a\n\n", settings);
-        await Verify("a\n", settings);
+        var exception = await Assert.ThrowsAnyAsync<Exception>(() => Verify("a\n", settings));
+        Assert.Contains("carriage return", exception.ToString());
 
+        // Trailing newlines are now compared exactly, with no tolerance
         await File.WriteAllTextAsync(file, "a\n");
         await Verify("a\n", settings);
-        await Verify("a", settings);
+        await Assert.ThrowsAsync<VerifyException>(() => Verify("a", settings));
 
         await File.WriteAllTextAsync(file, "a\n\n");
         await Verify("a\n\n", settings);
-        await Verify("a\n", settings);
+        await Assert.ThrowsAsync<VerifyException>(() => Verify("a\n", settings));
         File.Delete(file);
     }
-#endif
 
     //TODO: add test for trailing newlines
     // [Fact]

src/Verify/Compare/Comparer.cs

@@ -9,7 +9,12 @@ public static async Task<EqualityResult> Text(FilePair filePair, StringBuilder r
             return new(Equality.New, null, received, null);
         }
 
-        var verified = await IoHelpers.ReadStringBuilderWithFixedLines(filePair.VerifiedPath);
+        var verified = await File.ReadAllTextAsync(filePair.VerifiedPath);
+        if (verified.Contains('\r'))
+        {
+            throw new($@"Verified file must use \n line endings, but it contains a \r (carriage return). Path: {filePair.VerifiedPath}. See https://github.com/verifytests/verify#text-file-settings");
+        }
+
         var result = await CompareStrings(filePair.Extension, received, verified, settings, bypassComparer);
         if (result.IsEqual)
         {
@@ -20,36 +25,16 @@ public static async Task<EqualityResult> Text(FilePair filePair, StringBuilder r
         return new(Equality.NotEqual, result.Message, received, verified);
     }
 
-    static Task<CompareResult> CompareStrings(string extension, StringBuilder received, StringBuilder verified, VerifySettings settings, bool bypassComparer)
+    static Task<CompareResult> CompareStrings(string extension, StringBuilder received, string verified, VerifySettings settings, bool bypassComparer)
     {
-        if (verified.Length > 0 &&
-            verified.Length - 1 == received.Length &&
-            verified.LastChar() == '\n')
-        {
-            verified.Length -= 1;
-        }
-
-        // StringBuilder is broken on older .net https://github.com/dotnet/runtime/issues/27684
-#if NET6_0_OR_GREATER
-        var isEqual = verified.Equals(received);
-        if (!isEqual &&
-            !bypassComparer &&
-            settings.TryFindStringComparer(extension, out var compare))
-        {
-            return compare(received.ToString(), verified.ToString(), settings.Context);
-        }
-#else
-        var receivedString = received.ToString();
-        var verifiedString = verified.ToString();
-        var isEqual = receivedString.Equals(verifiedString);
+        var isEqual = received.Equals(verified.AsSpan());
         if (!isEqual &&
             !bypassComparer &&
             settings.TryFindStringComparer(extension, out var compare))
         {
-            return compare(receivedString, verifiedString, settings.Context);
+            return compare(received.ToString(), verified, settings.Context);
         }
-#endif
 
         return Task.FromResult(new CompareResult(isEqual));
     }
-}
+}

src/Verify/IoHelpers.cs

@@ -208,12 +208,6 @@ internal static string ResolveDirectoryFromSourceFile(string sourceFile)
         throw new($"Unable to resolve directory. sourceFile: {sourceFile}");
     }
 
-    public static async Task<StringBuilder> ReadStringBuilderWithFixedLines(string path)
-    {
-        using var stream = OpenRead(path);
-        return await stream.ReadStringBuilderWithFixedLines();
-    }
-
     public static async Task WriteStream(string path, Stream stream)
     {
         Directory.CreateDirectory(Path.GetDirectoryName(path)!);