Add unit tests for explicit interface implementation in FromExpression

src/Hangfire.Core/Common/Job.cs

@@ -375,7 +375,7 @@ private static void Validate(
         {
             if (!method.IsPublic)
             {
-                throw new NotSupportedException("Only public methods can be invoked in the background.");
+                throw new NotSupportedException("Only public methods can be invoked in the background. Ensure your method has the `public` access modifier, and you aren' using explicit interface implementation.");
             }
 
             if (method.ContainsGenericParameters)

tests/Hangfire.Core.Tests/Common/JobFacts.cs

@@ -286,6 +286,25 @@ public void FromScopedExpression_HandlesMethodsDeclaredInBaseClasse()
             Assert.Equal(typeof(Instance), job.Method.DeclaringType);
         }
 
+        [Fact]
+        public void FromScopedExpression_ThrowsWhenExplicitInterfaceImplementationIsPassed()
+        {
+            IService service = new ServiceImpl();
+            Assert.Throws<NotSupportedException>(() => Job.FromExpression(() => service.Method()));
+        }
+
+        public interface IService
+        {
+            void Method();
+        }
+
+        public class ServiceImpl : IService
+        {
+            void IService.Method()
+            {
+            }
+        }
+
         [Fact]
         public void Ctor_ThrowsAnException_WhenMethodContainsReferenceParameter()
         {