Hau-Hau · Hau-Hau · Dec 7, 2025 · Dec 7, 2025
diff --git a/.csharpierignore b/.csharpierignore
@@ -0,0 +1,2 @@
+# .csharpierignore
+!**/*.cs
diff --git a/EncryptedConfigValue.AspNetCore.Test/EncryptedConfigValue.AspNetCore.Test.csproj b/EncryptedConfigValue.AspNetCore.Test/EncryptedConfigValue.AspNetCore.Test.csproj
@@ -7,7 +7,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="FluentAssertions" Version="8.8.0" />
+		<PackageReference Include="Shouldly" Version="4.3.0" />
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
 		<PackageReference Include="NSubstitute" Version="5.3.0" />
 		<PackageReference Include="xunit" Version="2.9.3" />

diff --git a/EncryptedConfigValue.AspNetCore.Test/SubstitutingConfigurationFactoryTest.cs b/EncryptedConfigValue.AspNetCore.Test/SubstitutingConfigurationFactoryTest.cs
@@ -1,12 +1,13 @@
 using EncryptedConfigValue.AspNetCore.Test.Util;
 using EncryptedConfigValue.Crypto;
 using EncryptedConfigValue.Crypto.Util;
-using FluentAssertions;
 using Microsoft.Extensions.Configuration;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using Xunit;
+using Shouldly;
+using System.Text.RegularExpressions;
 
 namespace EncryptedConfigValue.AspNetCore.Test
 {
@@ -25,25 +26,25 @@ public void TestDecryptionSucceeds()
                 .AddEncryptedConfigValueProvider()
                 .Build();
 
-            configuration["Unencrypted"].Should().Be("value");
-            configuration["Encrypted"].Should().Be("value");
-            configuration["EncryptedWithSingleQuote"].Should().Be("don't use quotes");
-            configuration["EncryptedWithDoubleQuote"].Should().Be("double quote is \"");
-            configuration["EncryptedMalformedYaml"].Should().Be("[oh dear");
+            configuration["Unencrypted"].ShouldBe("value");
+            configuration["Encrypted"].ShouldBe("value");
+            configuration["EncryptedWithSingleQuote"].ShouldBe("don't use quotes");
+            configuration["EncryptedWithDoubleQuote"].ShouldBe("double quote is \"");
+            configuration["EncryptedMalformedYaml"].ShouldBe("[oh dear");
 
             configuration
                 .GetSection("ArrayWithSomeEncryptedValues")
                 .GetChildren()
                 .Select(x => x.Value)
-                .Should()
-                .BeEquivalentTo(new List<string> { "value", "value", "other value", "[oh dear" });
+                .ToList()
+                .ShouldBeEquivalentTo(new List<string> { "value", "value", "other value", "[oh dear" });
 
             var person = new Person();
             configuration
                 .GetSection("PocoWithEncryptedValues")
                 .Bind(person);
-            person.Username.Should().BeEquivalentTo("some-user");
-            person.Password.Should().BeEquivalentTo("value");
+            person.Username.ShouldBeEquivalentTo("some-user");
+            person.Password.ShouldBeEquivalentTo("value");
         }
 
         [Fact]
@@ -53,11 +54,10 @@ public void TestDecryptionFailsWithNiceMessage()
                 .AddJsonFile(Path.Combine("Resources", "testConfigWithError.json"), optional: false, reloadOnChange: false)
                 .AddEncryptedConfigValueProvider()
                 .Build();
-            act.Should()
-                .Throw<ConfigurationDecryptionException>()
-                .WithMessage($"Configuration decryption error at {Path.Combine("Resources", "testConfigWithError.json")} (*)")
-                .WithInnerExceptionExactly<StringSubstitutionException>()
-                .WithMessage("The value 'enc:ERROR' for field 'arrayWithSomeEncryptedValues:3' could not be replaced");
+            var ex = Should.Throw<ConfigurationDecryptionException>(act);
+            ex.Message.ShouldMatch($@"Configuration decryption error at {Regex.Escape(Path.Combine("Resources", "testConfigWithError.json"))} \(.*\)");
+            ex.InnerException.ShouldBeOfType<StringSubstitutionException>();
+            ex.InnerException.Message.ShouldBe("The value 'enc:ERROR' for field 'ArrayWithSomeEncryptedValues:3' could not be replaced");
         }
     }
 }
diff --git a/EncryptedConfigValue.AspNetCore.Test/VariableSubstitutionTest.cs b/EncryptedConfigValue.AspNetCore.Test/VariableSubstitutionTest.cs
@@ -1,6 +1,6 @@
 using EncryptedConfigValue.AspNetCore.Test.Util;
 using EncryptedConfigValue.Crypto;
-using FluentAssertions;
+using Shouldly;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.Configuration;
 using System;
@@ -31,25 +31,25 @@ private static WebApplication CreateWebApplication()
         [Fact]
         public void TestCanDecryptValueInConfig()
         {
-            aspnet.Configuration["Unencrypted"].Should().Be("value");
-            aspnet.Configuration["Encrypted"].Should().Be("value");
-            aspnet.Configuration["EncryptedWithSingleQuote"].Should().Be("don't use quotes");
-            aspnet.Configuration["EncryptedWithDoubleQuote"].Should().Be("double quote is \"");
-            aspnet.Configuration["EncryptedMalformedYaml"].Should().Be("[oh dear");
+            aspnet.Configuration["Unencrypted"].ShouldBe("value");
+            aspnet.Configuration["Encrypted"].ShouldBe("value");
+            aspnet.Configuration["EncryptedWithSingleQuote"].ShouldBe("don't use quotes");
+            aspnet.Configuration["EncryptedWithDoubleQuote"].ShouldBe("double quote is \"");
+            aspnet.Configuration["EncryptedMalformedYaml"].ShouldBe("[oh dear");
 
             aspnet.Configuration
                 .GetSection("ArrayWithSomeEncryptedValues")
                 .GetChildren()
                 .Select(x => x.Value)
-                .Should()
-                .BeEquivalentTo(new List<string> { "value", "value", "other value", "[oh dear" });
+                .ToList()
+                .ShouldBeEquivalentTo(new List<string> { "value", "value", "other value", "[oh dear" });
 
             var person = new Person();
             aspnet.Configuration
                 .GetSection("PocoWithEncryptedValues")
                 .Bind(person);
-            person.Username.Should().BeEquivalentTo("some-user");
-            person.Password.Should().BeEquivalentTo("value");
+            person.Username.ShouldBeEquivalentTo("some-user");
+            person.Password.ShouldBeEquivalentTo("value");
         }
     }
 }
diff --git a/EncryptedConfigValue.Cli.Test/EncryptConfigValueCommandTest.cs b/EncryptedConfigValue.Cli.Test/EncryptConfigValueCommandTest.cs
@@ -1,6 +1,6 @@
 using EncryptedConfigValue.Crypto;
 using EncryptedConfigValue.Crypto.Algorithm;
-using FluentAssertions;
+using Shouldly;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -69,7 +69,7 @@ internal void WeEncryptAndPrintAValue(Algorithm algorithm)
             var decryptionKey = keyPair.DecryptionKey;
             var decryptedValue = configValue.Decrypt(decryptionKey);
 
-            decryptedValue.Should().BeEquivalentTo(plaintext);
+            decryptedValue.ShouldBeEquivalentTo(plaintext);
         }
 
         [Fact]
@@ -100,7 +100,7 @@ internal void WeFailIfTheKeyfileDoesNotExist()
                 command.Execute("--keyfile", tempFilePath, "--value", plaintext);
             };
 
-            act.Should().Throw<FileNotFoundException>();
+            act.ShouldThrow<FileNotFoundException>();
         }
 
         public static IEnumerable<object[]> Data() =>

diff --git a/EncryptedConfigValue.Cli.Test/EncryptedConfigValue.Cli.Test.csproj b/EncryptedConfigValue.Cli.Test/EncryptedConfigValue.Cli.Test.csproj
@@ -15,8 +15,8 @@
 	</ItemGroup>
 
 	<ItemGroup>
-		<PackageReference Include="FluentAssertions" Version="8.8.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+		<PackageReference Include="Shouldly" Version="4.3.0" />
+    	<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
 		<PackageReference Include="xunit" Version="2.9.3" />
 		<PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

diff --git a/EncryptedConfigValue.Cli.Test/GenerateKeyCommandTest.cs b/EncryptedConfigValue.Cli.Test/GenerateKeyCommandTest.cs
@@ -1,6 +1,6 @@
 using EncryptedConfigValue.Crypto;
 using EncryptedConfigValue.Crypto.Algorithm;
-using FluentAssertions;
+using Shouldly;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -42,7 +42,7 @@ public void WeGenerateAValidKey(Algorithm algorithm)
             command.Execute("--algorithm", algorithm.ToString(), "--file", tempFilePath);
 
             var keyPair = KeyFileUtils.KeyPairFromPath(tempFilePath);
-            keyPair.EncryptionKey.Type.Algorithm.Should().BeEquivalentTo(algorithm);
+            keyPair.EncryptionKey.Type.Algorithm.ShouldBeEquivalentTo(algorithm);
         }
 
         [Fact]
@@ -62,8 +62,8 @@ public void WeDoNotOverwriteAnExistingKeyfile()
             {
                 command.Execute("--algorithm", algorithm.ToString(), "--file", tempFilePath);
             };
-
-            act.Should().Throw<IOException>().WithMessage("*already exists*");
+            var ex = Should.Throw<IOException>(act);
+            ex.Message.ShouldMatch("(.*)already exists*");
         }
 
         public static IEnumerable<object[]> Data() =>

diff --git a/EncryptedConfigValue.Module.Test/DecryptingVariableSubstitutorTest.cs b/EncryptedConfigValue.Module.Test/DecryptingVariableSubstitutorTest.cs
@@ -2,7 +2,7 @@
 using EncryptedConfigValue.Crypto.Algorithm;
 using EncryptedConfigValue.Crypto.Util;
 using EncryptedConfigValue.Module;
-using FluentAssertions;
+using Shouldly;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -63,7 +63,7 @@ public void Dispose()
         public void ConstantsAreNotModified()
         {
             substitutor.TryReplace("abc", out var output);
-            output.Should().BeEquivalentTo("abc");
+            output.ShouldBeEquivalentTo("abc");
         }
 
         [Fact]
@@ -76,30 +76,30 @@ public void InvalidEncryptedVariablesThrowStringSubstitutionException()
             }
             catch (StringSubstitutionException e)
             {
-                e.Value.Should().BeEquivalentTo("enc:invalid-contents");
-                e.Field.Should().BeEmpty();
+                e.Value.ShouldBeEquivalentTo("enc:invalid-contents");
+                e.Field.ShouldBeEmpty();
             }
         }
 
         [Fact]
         public void NonEncryptedVariablesAreNotModified()
         {
             substitutor.TryReplace("${abc}", out var output);
-            output.Should().BeEquivalentTo("${abc}");
+            output.ShouldBeEquivalentTo("${abc}");
         }
 
         [Fact]
         public void VariableIsDecrypted()
         {
             substitutor.TryReplace("${" + Encrypt("abc") + "}", out var output);
-            output.Should().BeEquivalentTo("abc");
+            output.ShouldBeEquivalentTo("abc");
         }
 
         [Fact]
         public void VariableIsDecryptedWithRegex()
         {
             substitutor.TryReplace("${" + Encrypt("$5") + "}", out var output);
-            output.Should().Be("$5");
+            output.ShouldBe("$5");
         }
 
         [Fact]
@@ -110,7 +110,7 @@ public void DecryptsMultiple()
             var hello = "${" + Encrypt("enc:hello") + "}";
             var source = abc + ":" + def + '.' + hello;
             substitutor.TryReplace(source, out var output);
-            output.Should().Be("abc:def.enc:hello");
+            output.ShouldBe("abc:def.enc:hello");
         }
 
         [Fact]
@@ -120,7 +120,7 @@ public void DecryptsWithPlaceholders()
             var def = "${" + Encrypt("${enc:test}") + "}";
             var source = abc + ":" + def;
             substitutor.TryReplace(source, out var output);
-            output.Should().BeEquivalentTo("abc:${enc:test}");
+            output.ShouldBeEquivalentTo("abc:${enc:test}");
         }
 
         [SkippableTheory]
@@ -131,7 +131,7 @@ public void PropertyTestValues(string plaintext)
             Skip.If(Encoding.UTF8.GetBytes(plaintext).Length > 190);
             EnsureTestKeysExist();
             substitutor.TryReplace("${" + Encrypt(plaintext) + "}", out var output);
-            output.Should().BeEquivalentTo(plaintext);
+            output.ShouldBeEquivalentTo(plaintext);
         }
 
         public static IEnumerable<object[]> PropertyTestData(int tries)

diff --git a/EncryptedConfigValue.Module.Test/EncryptedConfigValue.Module.Test.csproj b/EncryptedConfigValue.Module.Test/EncryptedConfigValue.Module.Test.csproj
@@ -7,11 +7,11 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="FluentAssertions" Version="8.8.0" />
+		<PackageReference Include="Shouldly" Version="4.3.0" />
 		<PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="10.0.0" />
 		<PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="10.0.0" />
 		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="10.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    	<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
 		<PackageReference Include="NSubstitute" Version="5.3.0" />
 		<PackageReference Include="xunit" Version="2.9.3" />
 		<PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">

diff --git a/EncryptedConfigValue.Test/Aes/AesKeyTest.cs b/EncryptedConfigValue.Test/Aes/AesKeyTest.cs
@@ -1,5 +1,5 @@
 using EncryptedConfigValue.Crypto.Algorithm.Aes;
-using FluentAssertions;
+using Shouldly;
 using Org.BouncyCastle.Crypto;
 using Org.BouncyCastle.Security;
 using Xunit;
@@ -19,7 +19,7 @@ public static byte[] NewSecretKey()
         public void TestEqualityFromSameSecretKey()
         {
             var secretKey = NewSecretKey();
-            new AesKey(secretKey).Should().BeEquivalentTo(new AesKey(secretKey));
+            new AesKey(secretKey).ShouldBeEquivalentTo(new AesKey(secretKey));
         }
     }
 }
diff --git a/EncryptedConfigValue.Test/AlgorithmTest.cs b/EncryptedConfigValue.Test/AlgorithmTest.cs
@@ -1,5 +1,5 @@
 using EncryptedConfigValue.Crypto.Algorithm;
-using FluentAssertions;
+using Shouldly;
 using System.Collections.Generic;
 using Xunit;
 
@@ -15,7 +15,8 @@ internal void WeGenerateRandomKeys(Algorithm algorithm)
         {
             var keyPair1 = algorithm.NewKeyPair();
             var keyPair2 = algorithm.NewKeyPair();
-            keyPair1.Should().NotBe(keyPair2).And.NotBeSameAs(keyPair2);
+            keyPair1.ShouldNotBe(keyPair2);
+            keyPair1.ShouldNotBeSameAs(keyPair2);
         }
 
         [Theory]
@@ -26,7 +27,7 @@ internal void WeCanEncryptAndDecrypt(Algorithm algorithm)
             var encryptedValue = algorithm.NewEncrypter().Encrypt(keyPair.EncryptionKey, plaintext);
             var decryptionKey = keyPair.DecryptionKey;
             var decrypted = encryptedValue.Decrypt(decryptionKey);
-            decrypted.Should().Be(plaintext);
+            decrypted.ShouldBe(plaintext);
         }
 
         [Theory]
@@ -38,17 +39,18 @@ internal void TheSameStringEncryptsToDifferentCiphertexts(Algorithm algorithm)
             var encrypted2 = algorithm.NewEncrypter().Encrypt(keyPair.EncryptionKey, plaintext);
 
             // we don't want to leak that certain values are the same
-            encrypted1.Should().NotBe(encrypted2).And.NotBeSameAs(encrypted2);
+            encrypted1.ShouldNotBe(encrypted2);
+            encrypted1.ShouldNotBeSameAs(encrypted2);
             // paranoia, let's say the equals method is badly behaved
-            encrypted1.GetHashCode().Should().NotBe(encrypted2.GetHashCode());
+            encrypted1.GetHashCode().ShouldNotBe(encrypted2.GetHashCode());
 
             // we should naturally decrypt back to the same thing - the plaintext
             var decryptionKey = keyPair.DecryptionKey;
             var decryptedString1 = encrypted1.Decrypt(decryptionKey);
             var decryptedString2 = encrypted2.Decrypt(decryptionKey);
 
-            decryptedString1.Should().Be(plaintext);
-            decryptedString2.Should().Be(plaintext);
+            decryptedString1.ShouldBe(plaintext);
+            decryptedString2.ShouldBe(plaintext);
         }
 
         public static IEnumerable<object[]> Data() => new[]

diff --git a/EncryptedConfigValue.Test/EncryptedConfigValue.Test.csproj b/EncryptedConfigValue.Test/EncryptedConfigValue.Test.csproj
@@ -7,7 +7,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="FluentAssertions" Version="8.8.0" />
+		<PackageReference Include="Shouldly" Version="4.3.0" />
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
 		<PackageReference Include="NSubstitute" Version="5.3.0" />
 		<PackageReference Include="xunit" Version="2.9.3" />

diff --git a/EncryptedConfigValue.Test/EncryptedValueCompatTest.cs b/EncryptedConfigValue.Test/EncryptedValueCompatTest.cs
@@ -1,5 +1,5 @@
 using EncryptedConfigValue.Crypto;
-using FluentAssertions;
+using Shouldly;
 using Xunit;
 
 namespace EncryptedConfigValue.Test
@@ -13,7 +13,7 @@ public void TestAesLegacyValue()
             EncryptedValue ev = EncryptedValue.FromString(
                     "enc:QjR4AHIYoIzvjEHf53XETM3QYnCl1mgFYC51Q7x4ebwM+h3PHVqSt/1un/+KvpJ2mZfMH0tifu+htRVxEPyXmt88lyKB83Npe"
                             + "sNJEoLFLL+wBWCkppaLRuc/1w==");
-            ev.Decrypt(kwa).Should().BeEquivalentTo("my secret. I don't want anyone to know this");
+            ev.Decrypt(kwa).ShouldBeEquivalentTo("my secret. I don't want anyone to know this");
         }
 
         [Fact]
@@ -23,7 +23,7 @@ public void TestAesNewValue()
             EncryptedValue ev = EncryptedValue.FromString(
                     "enc:eyJ0eXBlIjoiQUVTIiwibW9kZSI6IkdDTSIsImNpcGhlcnRleHQiOiJNOTRrSXlvYTUrMloiLCJpdiI6InVBR3FSbFA5d2l6c"
                             + "GRCMHoiLCJ0YWciOiJBQ1N1ekR3VFVMb21zanhwRk1rWUtBPT0ifQ==");
-            ev.Decrypt(kwa).Should().BeEquivalentTo("plaintext");
+            ev.Decrypt(kwa).ShouldBeEquivalentTo("plaintext");
         }
 
         [Fact]
@@ -51,7 +51,7 @@ public void TestRsaLegacyValue()
                             + "qrb08s46hodTPDLU76JNrtaxlCssXYxFN/Ni8k95pKauwPxRfvTP0SUf7o9rsZrY6LdV9+M3y6mNrEIKevAZQZtNmvX"
                             + "riclQGV1CwRzV/0sNVuTfNqNw0lDsI4hcvC26DhLrXla8jCUiKEYDFAqVr2DaTwtV3htxtCB36Jk6Lg5abdcc9B/ZqV"
                             + "7lfUIddGEuXFzhz8KIIGtwVVXqis15Dw1ECSNJhicHZp43vSYN9y9NJTnvTAhCQ==");
-            ev.Decrypt(kwa).Should().BeEquivalentTo("my secret. I don't want anyone to know this");
+            ev.Decrypt(kwa).ShouldBeEquivalentTo("my secret. I don't want anyone to know this");
         }
 
         [Fact]
@@ -83,7 +83,7 @@ public void TestRsaNewValue()
                             + "xROEVMNUVBWjJoNytscVY5Rmp0emxBdWtxbUp4OEVwMGhJbGhPUjIzNndJcWQwZHpBVzZnODYybENLb1Nob0dvS04y"
                             + "dHR5alU2TURRUWo0a0hBNFdCbTBOdm9XREZHN1p3T1ozbDIwVnY3R1ZRPT0iLCJvYWVwLWFsZyI6IlNIQS0yNTYiLC"
                             + "JtZGYxLWFsZyI6IlNIQS0yNTYifQ==");
-            ev.Decrypt(kwa).Should().BeEquivalentTo("plaintext");
+            ev.Decrypt(kwa).ShouldBeEquivalentTo("plaintext");
         }
     }
 }