feature: Add locations not null (#15)

Author: glennawatson

src/Splat.DependencyInjection.SourceGenerator/MetadataDependencyChecker.cs

@@ -46,7 +46,7 @@ public static List<MethodMetadata> CheckMetadata(GeneratorExecutionContext conte
                                 context.ReportDiagnostic(
                                     Diagnostic.Create(
                                         DiagnosticWarnings.ConstructorsMustNotHaveCircularDependency,
-                                        childConstructor.Parameter.Locations.FirstOrDefault() ?? metadataMethod.MethodInvocation.GetLocation()));
+                                        childConstructor.Parameter.Locations.FirstOrDefault(x => x is not null) ?? metadataMethod.MethodInvocation.GetLocation()));
                                 isError = true;
                             }
                         }
@@ -68,7 +68,7 @@ public static List<MethodMetadata> CheckMetadata(GeneratorExecutionContext conte
                             context.ReportDiagnostic(
                                 Diagnostic.Create(
                                     DiagnosticWarnings.LazyParameterNotRegisteredLazy,
-                                    constructorDependency.Parameter.Locations.FirstOrDefault() ?? metadataMethod.MethodInvocation.GetLocation(),
+                                    constructorDependency.Parameter.Locations.FirstOrDefault(x => x is not null) ?? metadataMethod.MethodInvocation.GetLocation(),
                                     metadataMethod.ConcreteTypeName,
                                     constructorDependency.Parameter.Name));
                             isError = true;

src/Splat.DependencyInjection.SourceGenerator/MetadataExtractor.cs

@@ -152,7 +152,7 @@ private static IEnumerable<ConstructorDependencyMetadata> GetConstructorDependen
                     {
                         if (returnConstructor != null)
                         {
-                            throw new ContextDiagnosticException(Diagnostic.Create(DiagnosticWarnings.MultipleConstructorsMarked, constructor.Locations.FirstOrDefault(), concreteTarget.ToDisplayString(RoslynCommonHelpers.TypeFormat)));
+                            throw new ContextDiagnosticException(Diagnostic.Create(DiagnosticWarnings.MultipleConstructorsMarked, constructor.Locations.FirstOrDefault(x => x is not null), concreteTarget.ToDisplayString(RoslynCommonHelpers.TypeFormat)));
                         }
 
                         returnConstructor = constructor;
@@ -167,7 +167,7 @@ private static IEnumerable<ConstructorDependencyMetadata> GetConstructorDependen
 
             if (returnConstructor.DeclaredAccessibility < Accessibility.Internal)
             {
-                throw new ContextDiagnosticException(Diagnostic.Create(DiagnosticWarnings.ConstructorsMustBePublic, returnConstructor.Locations.FirstOrDefault(), concreteTarget.ToDisplayString(RoslynCommonHelpers.TypeFormat)));
+                throw new ContextDiagnosticException(Diagnostic.Create(DiagnosticWarnings.ConstructorsMustBePublic, returnConstructor.Locations.FirstOrDefault(x => x is not null), concreteTarget.ToDisplayString(RoslynCommonHelpers.TypeFormat)));
             }
 
             return returnConstructor.Parameters.Select(x => new ConstructorDependencyMetadata(x, x.Type));
@@ -186,7 +186,7 @@ private static IEnumerable<PropertyDependencyMetadata> GetPropertyDependencies(I
             {
                 if (property.SetMethod?.DeclaredAccessibility < Accessibility.Internal)
                 {
-                    throw new ContextDiagnosticException(Diagnostic.Create(DiagnosticWarnings.PropertyMustPublicBeSettable, property.SetMethod?.Locations.FirstOrDefault(), property.ToDisplayString(RoslynCommonHelpers.TypeFormat)));
+                    throw new ContextDiagnosticException(Diagnostic.Create(DiagnosticWarnings.PropertyMustPublicBeSettable, property.SetMethod?.Locations.FirstOrDefault(x => x is not null), property.ToDisplayString(RoslynCommonHelpers.TypeFormat)));
                 }
 
                 yield return new(property);