Improve AssemblyNameInfo Fuzzer (dotnet#107257)

src/libraries/Fuzzing/DotnetFuzzing/Dictionaries/assemblynameinfo.dict

@@ -0,0 +1,16 @@
+"MyAssemblyName, Version=1.0.0.0, PublicKeyToken=b77a5c561934e089"
+"System.IO.Pipelines.Tests, PublicKey=00240000048000009400000006020000002400005253413100040000010001004b86c4cb78549b34bab61a3b1800e23bfeb5b3ec390074041536a7e3cbd97f5f04cf0f857155a8928eaa29ebfd11cfbbad3ba70efea7bda3226c6a8d370a4cd303f714486b6ebc225985a638471e6ef571cc92a4613c00b8fa65d61ccee0cbe5f36330c9a01f4183559f1bef24cc2917c6d913e3a541333a1d05d9bed22b38cb"
+"System.IO.Pipelines.Tests, PublicKey=null"
+"Abc, ProcessorArchitecture=X86"
+"Abc, ProcessorArchitecture=Amd64"
+"Abc, ProcessorArchitecture=Arm"
+"Abc, ProcessorArchitecture=MSIL"
+"Abc, ContentType=WindowsRuntime"
+"Abc, Retargetable=Yes"
+"Esc\\[aped"
+"MyAssemblyName, Version=1.0.0.0, PublicKeyToken=b77a5c561934e089", "MyAssemblyName, Version=1.0.0.0, PublicKeyToken=b77a5c561934e089"
+"MyAssemblyName, Version=1.0.0.0, PublicKey=00000000000000000400000000000000", "MyAssemblyName, Version=1.0.0.0, PublicKeyToken=b77a5c561934e089"
+"TerraFX.Interop.Windows, PublicKey=002400000c800000940000000602000000240000525341310004000001000100897039f5ff762b25b9ba982c3f5836c34e299279c33df505bf806a07bccdf0e1216e661943f557b954cb18422ed522a5b3174b85385052677f39c4ce19f30a1ddbaa507054bc5943461651f396afc612cd80419c5ee2b5277571ff65f51d14ba99e4e4196de0f393e89850a465f019dbdc365ed5e81bbafe1370f54efd254ba8, TerraFX.Interop.Windows, PublicKeyToken=35b01b53313a6f7e"
+"aaaa, language=en-en"
+"aaaa, foo=bar, foo=baz"
+"aa/name "

src/libraries/Fuzzing/DotnetFuzzing/Fuzzers/AssemblyNameInfoFuzzer.cs

@@ -4,6 +4,7 @@
 using System.Buffers;
 using System.Reflection.Metadata;
 using System.Runtime.InteropServices;
+using System.Text;
 
 namespace DotnetFuzzing.Fuzzers
 {
@@ -13,9 +14,12 @@ internal sealed class AssemblyNameInfoFuzzer : IFuzzer
 
         public string[] TargetCoreLibPrefixes => [];
 
+        public string Dictionary => "assemblynameinfo.dict";
+
         public void FuzzTarget(ReadOnlySpan<byte> bytes)
         {
-            ReadOnlySpan<char> chars = MemoryMarshal.Cast<byte, char>(bytes);
+            Span<char> chars = new char[Encoding.UTF8.GetCharCount(bytes)];
+            Encoding.UTF8.GetChars(bytes, chars);
 
             using PooledBoundedMemory<char> inputPoisonedBefore = PooledBoundedMemory<char>.Rent(chars, PoisonPagePlacement.Before);
             using PooledBoundedMemory<char> inputPoisonedAfter = PooledBoundedMemory<char>.Rent(chars, PoisonPagePlacement.After);
@@ -26,19 +30,51 @@ public void FuzzTarget(ReadOnlySpan<byte> bytes)
 
         private static void Test(PooledBoundedMemory<char> inputPoisoned)
         {
-            bool shouldSucceed = AssemblyNameInfo.TryParse(inputPoisoned.Span, out _);
-
-            try
+            if (AssemblyNameInfo.TryParse(inputPoisoned.Span, out AssemblyNameInfo? fromTryParse))
             {
-                AssemblyNameInfo.Parse(inputPoisoned.Span);
+                AssemblyNameInfo fromParse = AssemblyNameInfo.Parse(inputPoisoned.Span);
+
+                Assert.Equal(fromTryParse.Name, fromParse.Name);
+                Assert.Equal(fromTryParse.FullName, fromParse.FullName);
+                Assert.Equal(fromTryParse.CultureName, fromParse.CultureName);
+                Assert.Equal(fromTryParse.Flags, fromParse.Flags);
+                Assert.Equal(fromTryParse.Version, fromParse.Version);
+                Assert.SequenceEqual(fromTryParse.PublicKeyOrToken.AsSpan(), fromParse.PublicKeyOrToken.AsSpan());
+
+                Assert.Equal(fromTryParse.ToAssemblyName().Name, fromParse.ToAssemblyName().Name);
+                Assert.Equal(fromTryParse.ToAssemblyName().Version, fromParse.ToAssemblyName().Version);
+                Assert.Equal(fromTryParse.ToAssemblyName().ContentType, fromParse.ToAssemblyName().ContentType);
+                Assert.Equal(fromTryParse.ToAssemblyName().CultureName, fromParse.ToAssemblyName().CultureName);
+
+                Assert.Equal(fromTryParse.Name, fromParse.ToAssemblyName().Name);
+                Assert.Equal(fromTryParse.CultureName, fromParse.ToAssemblyName().CultureName);
+                Assert.Equal(fromTryParse.Version, fromParse.ToAssemblyName().Version);
+
+                // AssemblyNameInfo.FullName can be different than AssemblyName.FullName:
+                // AssemblyNameInfo includes public key, AssemblyName only its Token.
+
+                try
+                {
+                    Assert.Equal(fromTryParse.ToAssemblyName().FullName, fromParse.ToAssemblyName().FullName);
+                }
+                catch (System.Security.SecurityException)
+                {
+                    // AssemblyName.FullName performs public key validation, AssemblyNameInfo does not (on purpose).
+                }
             }
-            catch (ArgumentException)
+            else
             {
-                Assert.Equal(false, shouldSucceed);
-                return;
-            }
+                try
+                {
+                    _ = AssemblyNameInfo.Parse(inputPoisoned.Span);
+                }
+                catch (ArgumentException)
+                {
+                    return;
+                }
 
-            Assert.Equal(true, shouldSucceed);
+                throw new Exception("Parsing was supposed to fail!");
+            }
         }
     }
 }