Add JsonPCompiler

src/Authoring/IOutboundContext.cs

@@ -112,6 +112,12 @@ public interface IOutboundContext : IHaveExpressionContext
     /// </summary>
     /// <param name="config"></param>
     void JsonToXml(JsonToXmlConfig config);
+
+    /// <summary>
+    /// TODO
+    /// </summary>
+    /// <param name="callbackParameterName"></param>
+    void JsonP(string callbackParameterName);
 
     /// <summary>
     /// Inlines the specified policy as is to policy document.

src/Core/Compilation/CSharpPolicyCompiler.cs

@@ -30,6 +30,7 @@ public CSharpPolicyCompiler(ClassDeclarationSyntax document)
             new InlinePolicyCompiler(),
             new IpFilterCompiler(),
             new JsonToXmlCompiler(),
+            new JsonPCompiler(),
             new MockResponseCompiler(),
             new QuotaCompiler(),
             new RateLimitByKeyCompiler(),

src/Core/Compilation/Policy/JsonPCompiler.cs

@@ -0,0 +1,25 @@
+using System.Xml.Linq;
+
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+using Mielek.Azure.ApiManagement.PolicyToolkit.Authoring;
+
+namespace Mielek.Azure.ApiManagement.PolicyToolkit.Compilation.Policy;
+
+public class JsonPCompiler : IMethodPolicyHandler
+{
+    public string MethodName => nameof(IOutboundContext.JsonP);
+
+    public void Handle(ICompilationContext context, InvocationExpressionSyntax node)
+    {
+        var arguments = node.ArgumentList.Arguments;
+        if (arguments.Count != 1)
+        {
+            context.ReportError($"Wrong argument count for jsonp policy. {node.GetLocation()}");
+            return;
+        }
+
+        var value = node.ArgumentList.Arguments[0].Expression.ProcessParameter(context);
+        context.AddPolicy(new XElement("jsonp", new XAttribute("callback-parameter-name", value)));
+    }
+}

test/Test.Core/Compilation/JsonPTests.cs

@@ -0,0 +1,51 @@
+namespace Mielek.Azure.ApiManagement.PolicyToolkit.Compilation;
+
+[TestClass]
+public class JsonPTests
+{
+    [TestMethod]
+    [DataRow(
+        """
+        [Document]
+        public class PolicyDocument : IDocument
+        {
+            public void Outbound(IOutboundContext context) {
+                context.JsonP("cb");
+            }
+        }
+        """,
+        """
+        <policies>
+            <outbound>
+                <jsonp callback-parameter-name="cb" />
+            </outbound>
+        </policies>
+        """,
+        DisplayName = "Should compile jsonp policy"
+    )]
+    [DataRow(
+        """
+        [Document]
+        public class PolicyDocument : IDocument
+        {
+            public void Outbound(IOutboundContext context) {
+                context.JsonP(Exp(context.ExpressionContext));
+            }
+            public string Exp(IExpressionContext context) => context.User.Name;
+        }
+        """,
+        """
+        <policies>
+            <outbound>
+                <jsonp callback-parameter-name="@(context.User.Name)" />
+            </outbound>
+        </policies>
+        """,
+        DisplayName = "Should compile jsonp policy with expression"
+    )]
+    public void ShouldCompileJsonPPolicy(string code, string expectedXml)
+    {
+        code.CompileDocument().Should().BeSuccessful().And.DocumentEquivalentTo(expectedXml);
+    }
+
+}