getting the type out of string is hard

source/graphql/helper.d

@@ -443,10 +443,11 @@ const(Document) lexAndParse(string s) {
 
 string stringTypeStrip(string str) {
 	import std.algorithm.searching : startsWith, endsWith, canFind;
-	import std.string : capitalize;
+	import std.string : capitalize, indexOf, strip;
 	immutable fs = ["Nullable!", "NullableStore!", "GQLDCustomLeaf!"];
 	immutable arr = "[]";
 	outer: while(true) {
+		str = str.strip();
 		foreach(f; fs) {
 			if(str.startsWith(f)) {
 				str = str[f.length .. $];
@@ -478,6 +479,9 @@ string stringTypeStrip(string str) {
 		break;
 	}
 
+	const comma = str.indexOf(',');
+	str = comma == -1 ? str : str[0 .. comma].strip();
+
 	str = canFind(["ubyte", "byte", "ushort", "short", "long", "ulong"], str)
 		? "Int"
 		: str;
@@ -515,17 +519,65 @@ unittest {
 	assert(r == "__Type", r);
 }
 
-Json toGraphqlJson(T)(auto ref T obj) {
+Json toGraphqlJson(T)(auto ref T input) {
+	import std.typecons : Nullable;
+	import std.array : empty;
+	import std.traits : isArray, isAggregateType, isBasicType, isSomeString,
+		   isScalarType, isSomeString, FieldNameTuple, FieldTypeTuple;
+
+	import nullablestore;
+
 	import graphql.uda : GQLDCustomLeaf;
-	import std.traits : isArray, FieldNameTuple, FieldTypeTuple;
+	static if(isArray!T && !isSomeString!T) {
+		Json ret = Json.emptyArray();
+		foreach(ref it; input) {
+			ret ~= toGraphqlJson(it);
+		}
+		return ret;
+	} else static if(is(T : GQLDCustomLeaf!Type, Type...)) {
+		return Json(Type[1](input));
+	} else static if(is(T : Nullable!Type, Type)) {
+		return input.isNull() ? Json(null) : toGraphqlJson(input.get());
+	} else static if(isBasicType!T || isScalarType!T || isSomeString!T) {
+		return serializeToJson(input);
+	} else static if(isAggregateType!T) {
+		Json ret = Json.emptyObject();
+
+		// the important bit is the setting of the __typename field
+		ret["__typename"] = T.stringof;
+		alias names = FieldNameTuple!(T);
+		alias types = FieldTypeTuple!(T);
+		static foreach(idx; 0 .. names.length) {{
+			static if(!names[idx].empty) {
+				static if(is(types[idx] : NullableStore!Type, Type)) {
+				} else static if(is(types[idx] == enum)) {
+					ret[names[idx]] = serializeToJson(
+							__traits(getMember, input, names[idx])
+						);
+				} else {
+					ret[names[idx]] = toGraphqlJson(
+							__traits(getMember, input, names[idx])
+						);
+				}
+			}
+		}}
+		return ret;
+	} else {
+		static assert(false, T.stringof ~ " not supported");
+	}
+}
+
+/*Json toGraphqlJson(T)(auto ref T obj) {
+	import graphql.uda : GQLDCustomLeaf;
+	import std.traits : isArray, isSomeString, FieldNameTuple, FieldTypeTuple;
 	import std.array : empty;
 	import std.typecons : Nullable;
 	import nullablestore;
 
 	alias names = FieldNameTuple!(T);
 	alias types = FieldTypeTuple!(T);
 
-	static if(isArray!T) {
+	static if(isArray!T && !isSomeString!T) {
 		Json ret = Json.emptyArray();
 		foreach(ref it; obj) {
 			ret ~= toGraphqlJson(it);
@@ -563,7 +615,7 @@ Json toGraphqlJson(T)(auto ref T obj) {
 		}}
 	}
 	return ret;
-}
+}*/
 
 string dtToString(DateTime dt) {
 	return dt.toISOExtString();

source/graphql/schema/typeconversions.d

@@ -52,12 +52,13 @@ template typeToTypeEnum(Type) {
 }
 
 template typeToTypeName(Type) {
+	import graphql.uda : GQLDCustomLeaf;
 	static if(is(Type == enum)) {
 		enum typeToTypeName = Type.stringof;
 	} else static if(is(Type == bool)) {
 		enum typeToTypeName = "Bool";
-	} else static if(is(Type == GQLDCustomLeaf!F, F)) {
-		enum typeToTypeName = F.stringof;
+	} else static if(is(Type == GQLDCustomLeaf!Fs, Fs...)) {
+		enum typeToTypeName = Fs[0].stringof;
 	} else static if(isFloatingPoint!(Type)) {
 		enum typeToTypeName = "Float";
 	} else static if(isIntegral!(Type)) {
@@ -69,6 +70,11 @@ template typeToTypeName(Type) {
 	}
 }
 
+unittest {
+	import std.datetime : Date;
+	static assert(typeToTypeName!(GQLDCustomLeaf!Date) == "Date");
+}
+
 template typeToParameterTypeName(Type) {
 	template level2(Type) {
 		static if(is(Type : Nullable!F, F)) {
@@ -111,7 +117,7 @@ unittest {
 template isScalarType(Type) {
 	static if(is(Type == bool)) {
 		enum isScalarType = true;
-	} else static if(is(Type == GQLDCustomLeaf!F, F)) {
+	} else static if(is(Type == GQLDCustomLeaf!Fs, Fs...)) {
 		enum isScalarType = true;
 	} else static if(isFloatingPoint!(Type)) {
 		enum isScalarType = true;
@@ -321,7 +327,7 @@ Json typeToJsonImpl(Type,Schema,Orig)() {
 	// fields
 	static if((is(Type == class) || is(Type == interface) || is(Type == struct))
 			&& !is(Type : Nullable!K, K) && !is(Type : NullableStore!K, K)
-			&& !is(Type : GQLDCustomLeaf!K, K))
+			&& !is(Type : GQLDCustomLeaf!Ks, Ks...))
 	{
 		ret[Constants.fields] = typeFields!Type();
 	} else {
@@ -376,9 +382,9 @@ Json typeToJsonImpl(Type,Schema,Orig)() {
 
 	// needed to resolve ofType
 	static if(is(Type : Nullable!F, F) || is(Type : NullableStore!F, F)
-			|| is(Type : GQLDCustomLeaf!F, F))
+			|| is(Type : GQLDCustomLeaf!Fs, Fs...))
 	{
-		ret[Constants.ofTypeName] = F.stringof;
+		ret[Constants.ofTypeName] = Fs[0].stringof;
 	} else static if(isArray!Type) {
 		ret[Constants.ofTypeName] = ElementEncodingType!(Type).stringof;
 	}

source/graphql/traits.d

@@ -118,7 +118,7 @@ template isNotObject(Type) {
 
 template isNotCustomLeaf(Type) {
 	import graphql.uda;
-	enum isNotCustomLeaf = !is(Type : GQLDCustomLeaf!F, F);
+	enum isNotCustomLeaf = !is(Type : GQLDCustomLeaf!Fs, Fs...);
 }
 
 unittest {
@@ -129,7 +129,7 @@ unittest {
 
 template collectTypesImpl(Type) {
 	import graphql.uda;
-	static if(is(Type : GQLDCustomLeaf!F, F)) {
+	static if(is(Type : GQLDCustomLeaf!Fs, Fs...)) {
 		alias collectTypesImpl = AliasSeq!(Type);
 	} else static if(is(Type == interface)) {
 		alias RetTypes = AliasSeq!(collectReturnType!(Type,
@@ -266,6 +266,9 @@ template fixupBasicTypes(T) {
 	} else static if(isArray!T) {
 		alias ElemFix = fixupBasicTypes!(ElementEncodingType!T);
 		alias fixupBasicTypes = ElemFix[];
+	} else static if(is(T : GQLDCustomLeaf!Fs, Fs...)) {
+		alias ElemFix = fixupBasicTypes!(Fs[0]);
+		alias fixupBasicTypes = GQLDCustomLeaf!(ElemFix, Fs[1 .. $]);
 	} else static if(is(T : Nullable!F, F)) {
 		alias ElemFix = fixupBasicTypes!(F);
 		alias fixupBasicTypes = Nullable!(ElemFix);

source/graphql/validation/schemabased.d

@@ -102,6 +102,7 @@ class SchemaValidator(Schema) : Visitor {
 					this.schemaStack.back.name, name)
 			);
 
+
 		string followType = field[Constants.typenameOrig].get!string();
 		string old = followType;
 		followType = followType.stringTypeStrip();