Add simple diagnostic output to InterfaceStubGenerator.

InterfaceStubGenerator/Diagnostics.cs

@@ -0,0 +1,99 @@
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+
+namespace Refit.Generator
+{
+    public class Diagnostic
+    {
+        public string Type { get; private set; }
+        public string Code { get; private set; }
+        public string File { get; protected set; }
+        public int? Line { get; protected set; }
+        public int? Character { get; protected set; }
+        public string Message { get; protected set; }
+
+        public Diagnostic(string type, string code)
+        {
+            Type = type;
+            Code = code;
+        }
+
+        protected void setLocation(Location location)
+        {
+            var line = location.GetMappedLineSpan().StartLinePosition;
+
+            File = location.FilePath;
+            Line = line.Line + 1;
+            Character = line.Character + 1;
+        }
+
+        public override string ToString()
+        {
+            var builder = new StringBuilder();
+
+            if (!string.IsNullOrWhiteSpace(File)) {
+                builder.Append(File);
+                if (Line.HasValue) {
+                    builder.AppendFormat("({0}", Line);
+                    if (Character.HasValue)
+                        builder.AppendFormat(",{0}", Character);
+                    builder.Append(")");
+                }
+                builder.Append(": ");
+            }
+            builder.AppendFormat("{0} {1}", Type, Code);
+            if (!string.IsNullOrWhiteSpace(Message))
+                builder.AppendFormat(": {0}", Message);
+
+            return builder.ToString();
+        }
+    }
+
+    public class Warning : Diagnostic
+    {
+        public Warning(string code) : base("warning", code) { }
+    }
+
+    public class MissingRefitAttributeWarning : Warning
+    {
+        public string InterfaceName { get; private set; }
+        public string MethodName { get; private set; }
+
+        public MissingRefitAttributeWarning(InterfaceDeclarationSyntax @interface, MethodDeclarationSyntax method)
+            : base("RF001")
+        {
+            setLocation(method.GetLocation());
+
+            InterfaceName = @interface.Identifier.Text;
+            MethodName = method.Identifier.Text;
+
+            Message = string.Format(
+                "Method {0}.{1} either has no Refit HTTP method attribute or you've used something other than a string literal for the 'path' argument.",
+                InterfaceName, MethodName);
+        }
+    }
+
+    public class MultipleRefitMethodSameNameWarning : Warning
+    {
+        public string InterfaceName { get; private set; }
+        public string MethodName { get; private set; }
+
+        public MultipleRefitMethodSameNameWarning(InterfaceDeclarationSyntax @interface, MethodDeclarationSyntax method)
+            : base("RF002")
+        {
+            setLocation(method.GetLocation());
+
+            InterfaceName = @interface.Identifier.Text;
+            MethodName = method.Identifier.Text;
+
+            Message = string.Format(
+                "Method {0}.{1} has been declared multiple times. Refit doesn't support overloading.",
+                InterfaceName, MethodName);
+        }
+    }
+}

InterfaceStubGenerator/InterfaceStubGenerator.cs

@@ -34,6 +34,8 @@ public string GenerateInterfaceStubs(string[] paths)
 
             var templateInfo = GenerateTemplateInfoForInterfaceList(interfacesToGenerate);
 
+            GenerateWarnings(interfacesToGenerate);
+
             Encoders.HtmlEncode = (s) => s;
             var text = Render.StringToString(ExtractTemplateSource(), templateInfo);
             return text;
@@ -126,6 +128,27 @@ public ClassTemplateInfo GenerateClassInfoForInterface(InterfaceDeclarationSynta
             return ret;
         }
 
+        public void GenerateWarnings(List<InterfaceDeclarationSyntax> interfacesToGenerate)
+        {
+            var missingAttributeWarnings = interfacesToGenerate
+                .SelectMany(i => i.Members.OfType<MethodDeclarationSyntax>().Select(m => new {Interface = i, Method = m}))
+                .Where(x => !HasRefitHttpMethodAttribute(x.Method))
+                .Select(x => new MissingRefitAttributeWarning(x.Interface, x.Method));
+
+            var overloadWarnings = interfacesToGenerate
+                .SelectMany(i => i.Members.OfType<MethodDeclarationSyntax>().Select(m => new {Interface = i, Method = m}))
+                .Where(x => HasRefitHttpMethodAttribute(x.Method))
+                .GroupBy(x => new {Interface = x.Interface, MethodName = x.Method.Identifier.Text})
+                .Where(g => g.Count() > 1)
+                .SelectMany(g => g.Select(x => new MultipleRefitMethodSameNameWarning(x.Interface, x.Method)));
+
+            var diagnostics = missingAttributeWarnings.Concat<Diagnostic>(overloadWarnings);
+
+            foreach (var diagnostic in diagnostics) {
+                Console.Error.WriteLine(diagnostic);
+            }
+        }
+
         public static string ExtractTemplateSource()
         {
             var ourPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

InterfaceStubGenerator/InterfaceStubGenerator.csproj

@@ -75,6 +75,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Diagnostics.cs" />
     <Compile Include="InterfaceStubGenerator.cs" />
     <Compile Include="Mono.Options\Options.cs" />
     <Compile Include="Program.cs" />
@@ -95,4 +96,4 @@
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
+</Project>

Refit-Tests/MethodOverloads.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Threading.Tasks;
+using Refit;
+
+namespace Refit.Tests
+{
+    public interface IUseOverloadedMethods
+    {
+        [Get("/")]
+        Task Get();
+
+        [Get("/{id}")]
+        Task Get(int id);
+    }
+}
+

Refit-Tests/Refit-Tests-Android.csproj

@@ -72,6 +72,7 @@
     <Compile Include="GitHubApi.cs" />
     <Compile Include="IntegrationTestHelper.cs" />
     <Compile Include="RefitStubs.cs" />
+    <Compile Include="MethodOverloads.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="Resources\AboutResources.txt" />

Refit-Tests/Refit-Tests-Net45.csproj

@@ -112,6 +112,7 @@
     <Compile Include="RefitStubs.cs" />
     <Compile Include="RequestBuilder.cs" />
     <Compile Include="RestService.cs" />
+    <Compile Include="MethodOverloads.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\InterfaceStubGenerator\InterfaceStubGenerator.csproj">

Refit-Tests/Refit-Tests-iOS.csproj

@@ -129,6 +129,7 @@
     <Compile Include="RestService.cs" />
     <Compile Include="RefitStubs.cs" />
     <Compile Include="DeliminatorSeparatedPropertyNamesContractResolver.cs" />
+    <Compile Include="MethodOverloads.cs" />
   </ItemGroup>
 
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />