- fixes coverage and linting feedback

Signed-off-by: Vincent Biret <vibiret@microsoft.com>

src/Kiota.Builder/Exceptions/InvalidSchemaException.cs

@@ -3,9 +3,12 @@
 
 namespace Kiota.Builder.Exceptions;
 
+[Serializable]
 public class InvalidSchemaException : InvalidOperationException
 {
-    public InvalidSchemaException(string message) : base(message)
-    {
-    }
+    public InvalidSchemaException():base(){}
+    public InvalidSchemaException(string message) : base(message){}
+    #nullable enable
+    public InvalidSchemaException(string? message, Exception? innerException):base(message, innerException){}
+    #nullable disable
 }

tests/Kiota.Builder.Tests/Exceptions/InvalidSchemaExceptionTests.cs

@@ -0,0 +1,14 @@
+
+using System;
+using Xunit;
+
+namespace Kiota.Builder.Exceptions.Tests;
+
+public class InvalidSchemaExceptionTests {
+    [Fact]
+    public void Instantiates() {
+        Assert.NotNull(new InvalidSchemaException());
+        Assert.NotNull(new InvalidSchemaException("message"));
+        Assert.NotNull(new InvalidSchemaException("message", new InvalidOperationException()));
+    }
+}