fix(kernel): cannot pass decorated structs to kernel as "any" (#997)

When a struct is serialized with a $jsii.struct decoration from a jsii host language and passed into a value typed any, the kernel ignored the decoration. This resulted in a malformed object passed to the javascript code.

This fix undecorates the object and continues to deserialize it as a struct.

Also, increase kernel unit test coverage for serialization and deserialization of "any".

Fixes aws/aws-cdk#5066

packages/jsii-calc/lib/compliance.ts

@@ -2331,3 +2331,68 @@ export class ObjectWithPropertyProvider {
 
     private constructor() { }
 }
+
+/**
+ * Make sure structs are un-decorated on the way in.
+ *
+ * @see https://github.com/aws/aws-cdk/issues/5066
+ */
+export class JsonFormatter {
+    public static stringify(value?: any): string | undefined {
+        return JSON.stringify(value, null, 2);
+    }
+
+    public static anyNull(): any {
+        return null;
+    }
+
+    public static anyUndefined(): any {
+        return undefined;
+    }
+
+    public static anyFunction(): any {
+        return () => 'boom';
+    }
+
+    public static anyDate(): any { 
+        return new Date('2019-11-18T13:01:20.515Z');
+    }
+
+    public static anyNumber(): any {
+        return 123;
+    }
+
+    public static anyZero(): any {
+        return 0;
+    }
+
+    public static anyString(): any {
+        return 'foo';
+    }
+
+    public static anyEmptyString(): any {
+        return '';
+    }
+
+    public static anyBooleanTrue(): any {
+        return true;
+    }
+
+    public static anyBooleanFalse(): any {
+        return false;
+    }
+
+    public static anyArray(): any {
+        return [ 1, 2, 3, new Number(123), { foo: 'bar' } ];
+    }
+
+    public static anyHash(): any {
+        return { hello: 1234, world: new Number(122) };
+    }
+
+    public static anyRef(): any {
+        return new Number(444);
+    }
+
+    private constructor() { }
+}

packages/jsii-calc/test/assembly.jsii

@@ -6826,6 +6826,257 @@
         }
       ]
     },
+    "jsii-calc.JsonFormatter": {
+      "assembly": "jsii-calc",
+      "docs": {
+        "see": "https://github.com/aws/aws-cdk/issues/5066",
+        "stability": "experimental",
+        "summary": "Make sure structs are un-decorated on the way in."
+      },
+      "fqn": "jsii-calc.JsonFormatter",
+      "kind": "class",
+      "locationInModule": {
+        "filename": "lib/compliance.ts",
+        "line": 2340
+      },
+      "methods": [
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2385
+          },
+          "name": "anyArray",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2381
+          },
+          "name": "anyBooleanFalse",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2377
+          },
+          "name": "anyBooleanTrue",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2357
+          },
+          "name": "anyDate",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2373
+          },
+          "name": "anyEmptyString",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2353
+          },
+          "name": "anyFunction",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2389
+          },
+          "name": "anyHash",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2345
+          },
+          "name": "anyNull",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2361
+          },
+          "name": "anyNumber",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2393
+          },
+          "name": "anyRef",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2369
+          },
+          "name": "anyString",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2349
+          },
+          "name": "anyUndefined",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2365
+          },
+          "name": "anyZero",
+          "returns": {
+            "type": {
+              "primitive": "any"
+            }
+          },
+          "static": true
+        },
+        {
+          "docs": {
+            "stability": "experimental"
+          },
+          "locationInModule": {
+            "filename": "lib/compliance.ts",
+            "line": 2341
+          },
+          "name": "stringify",
+          "parameters": [
+            {
+              "name": "value",
+              "optional": true,
+              "type": {
+                "primitive": "any"
+              }
+            }
+          ],
+          "returns": {
+            "optional": true,
+            "type": {
+              "primitive": "string"
+            }
+          },
+          "static": true
+        }
+      ],
+      "name": "JsonFormatter"
+    },
     "jsii-calc.LoadBalancedFargateServiceProps": {
       "assembly": "jsii-calc",
       "datatype": true,
@@ -11413,5 +11664,5 @@
     }
   },
   "version": "0.20.6",
-  "fingerprint": "veHd1Q/376CoMR3O/DjjAiH9aVD/jcwnPEg88barg9I="
+  "fingerprint": "xRnF3HrD87xlfIYG262JFu5WEdrC0eQelRBEzyQyARo="
 }

packages/jsii-dotnet-runtime-test/test/Amazon.JSII.Runtime.IntegrationTests/ComplianceTests.cs

@@ -1297,5 +1297,18 @@ public void CanUseInterfaceSetters()
             obj.Property = "New Value";
             Assert.True(obj.WasSet());
         }
+
+        [Fact(DisplayName = Prefix + nameof(StructsAreUndecoratedOntheWayToKernel))]
+        public void StructsAreUndecoratedOntheWayToKernel()
+        {
+            var json = JsonFormatter.Stringify(new StructB {RequiredString = "Bazinga!", OptionalBoolean = false});
+            var actual = JObject.Parse(json);
+
+            var expected = new JObject();
+            expected.Add("RequiredString", "Bazinga!");
+            expected.Add("OptionalBoolean", false);
+
+            Assert.Equal(expected, actual);
+        }
     }
 }

packages/jsii-dotnet-runtime/src/Amazon.JSII.Runtime/Deputy/JsiiByValueAttribute.cs

@@ -7,9 +7,9 @@ public sealed class JsiiByValueAttribute : Attribute
     {
         public JsiiByValueAttribute(string fqn)
         {
-            Fqn = fqn ?? throw new ArgumentNullException(nameof(fqn));
+            FullyQualifiedName = fqn ?? throw new ArgumentNullException(nameof(fqn));
         }
 
-        public string Fqn { get; } 
+        public string FullyQualifiedName { get; } 
     }
 }

packages/jsii-dotnet-runtime/src/Amazon.JSII.Runtime/Services/Converters/FrameworkToJsiiConverter.cs

@@ -72,7 +72,7 @@ protected override bool TryConvertClass(Type type, IReferenceMap referenceMap, o
                 }
 
                 var structInfo = new JObject();
-                structInfo.Add(new JProperty("fqn", byValueAttribute.Fqn));
+                structInfo.Add(new JProperty("fqn", byValueAttribute.FullyQualifiedName));
                 structInfo.Add(new JProperty("data", data));
 
                 var resultObject = new JObject();
@@ -353,6 +353,12 @@ TypeReference InferType(IReferenceMap referenceMap, Type type)
                 return new TypeReference(enumAttribute.FullyQualifiedName);
             }
 
+            JsiiByValueAttribute structAttribute = type.GetCustomAttribute<JsiiByValueAttribute>();
+            if (structAttribute != null)
+            {
+                return new TypeReference(structAttribute.FullyQualifiedName);
+            }
+
             if (typeof(string).IsAssignableFrom(type))
             {
                 return new TypeReference(primitive: PrimitiveType.String);