--- a/spec/util_datamapper_spec.lua	Fri Jul 08 14:38:23 2022 +0200
+++ b/spec/util_datamapper_spec.lua	Fri Jul 08 17:32:48 2022 +0200
@@ -25,7 +25,7 @@
 				from = attr();
 				type = attr();
 				id = attr();
-				body = "string";
+				body = true; -- should be assumed to be a string
 				lang = {type = "string"; xml = {attribute = true; prefix = "xml"}};
 				delay = {
 					type = "object";
@@ -56,7 +56,8 @@
 					xml = {namespace = "urn:xmpp:reactions:0"; name = "reactions"};
 					properties = {
 						to = {type = "string"; xml = {attribute = true; name = "id"}};
-						reactions = {type = "array"; items = {type = "string"; xml = {name = "reaction"}}};
+						-- should be assumed to be array since it has 'items'
+						reactions = { items = { xml = { name = "reaction" } } };
 					};
 				};
 				stanza_ids = {
@@ -190,7 +191,8 @@
 					version = {
 						type = "object";
 						xml = {name = "query"; namespace = "jabber:iq:version"};
-						properties = {name = "string"; version = "string"; os = "string"};
+						-- properties should be assumed to be strings
+						properties = {name = true; version = {}; os = {}};
 					};
 				};
 			};

--- a/teal-src/util/datamapper.tl	Fri Jul 08 14:38:23 2022 +0200
+++ b/teal-src/util/datamapper.tl	Fri Jul 08 17:32:48 2022 +0200
@@ -25,7 +25,7 @@
 
 local json_type_name = json.json_type_name;
 local json_schema_object = require "util.jsonschema"
-local type schema_t = boolean | json_type_name | json_schema_object
+local type schema_t = boolean | json_schema_object
 
 local function toboolean ( s : string ) : boolean
 	if s == "true" or s == "1" then
@@ -59,15 +59,28 @@
 end
 
 local function resolve_schema(schema  : schema_t, root : json_schema_object) : schema_t
-	if schema is json_schema_object and schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
-		local referenced = pointer.resolve(root as table, schema["$ref"]:sub(2)) as schema_t;
-		if referenced ~= nil then
-			return referenced
+	if schema is json_schema_object then
+		if schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
+			return pointer.resolve(root as table, schema["$ref"]:sub(2)) as schema_t;
 		end
 	end
 	return schema;
 end
 
+local function guess_schema_type(schema : json_schema_object) : json_type_name
+	local schema_types = schema.type
+	if schema_types is json_type_name then
+		return schema_types
+	elseif schema_types ~= nil then
+		error "schema has unsupported 'type' property"
+	elseif schema.properties then
+		return "object"
+	elseif schema.items then
+		return "array"
+	end
+	return "string" -- default assumption
+end
+
 local function unpack_propschema( propschema : schema_t, propname : string, current_ns : string )
 		: json_type_name, value_goes, string, string, string, string, { any }
 	local proptype : json_type_name = "string"
@@ -79,9 +92,9 @@
 	local enums : { any }
 
 	if propschema is json_schema_object then
-		proptype = propschema.type
-	elseif propschema is json_type_name then
-		proptype = propschema
+		proptype = guess_schema_type(propschema);
+	elseif propschema is string then -- Teal says this can never be a string, but it could before so best be sure
+		error("schema as string is not supported: "..propschema.." {"..current_ns.."}"..propname)
 	end
 
 	if proptype == "object" or proptype == "array" then
@@ -120,6 +133,10 @@
 		end
 	end
 
+	if current_ns == "urn:xmpp:reactions:0" and name == "reactions" then
+		assert(proptype=="array")
+	end
+
 	return proptype, value_where, name, namespace, prefix, single_attribute, enums
 end
 
@@ -239,9 +256,10 @@
 end
 
 local function parse (schema : json_schema_object, s : st.stanza_t) : table
-	if schema.type == "object" then
+	local s_type = guess_schema_type(schema)
+	if s_type == "object" then
 		return parse_object(schema, s, schema)
-	elseif schema.type == "array" then
+	elseif s_type == "array" then
 		return parse_array(schema, s, schema)
 	else
 		error "top-level scalars unsupported"
@@ -333,7 +351,8 @@
 
 	local out = ctx or st.stanza(current_name, { xmlns = current_ns })
 
-	if schema.type == "object" then
+	local s_type = guess_schema_type(schema)
+	if s_type == "object" then
 
 		for prop, propschema in pairs(schema.properties) do
 			propschema = resolve_schema(propschema, root)
@@ -346,7 +365,7 @@
 		end
 		return out;
 
-	elseif schema.type == "array" then
+	elseif s_type == "array" then
 		local itemschema = resolve_schema(schema.items, root)
 		local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(itemschema, current_name, current_ns)
 		for _, item in ipairs(t as { string }) do

--- a/util/datamapper.lua	Fri Jul 08 14:38:23 2022 +0200
+++ b/util/datamapper.lua	Fri Jul 08 17:32:48 2022 +0200
@@ -1,3 +1,5 @@
+-- This file is generated from teal-src/util/datamapper.lua
+
 local st = require("util.stanza");
 local pointer = require("util.jsonpointer");
 
@@ -29,15 +31,28 @@
 local value_goes = {}
 
 local function resolve_schema(schema, root)
-	if type(schema) == "table" and schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
-		local referenced = pointer.resolve(root, schema["$ref"]:sub(2));
-		if referenced ~= nil then
-			return referenced
+	if type(schema) == "table" then
+		if schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
+			return pointer.resolve(root, schema["$ref"]:sub(2))
 		end
 	end
 	return schema
 end
 
+local function guess_schema_type(schema)
+	local schema_types = schema.type
+	if type(schema_types) == "string" then
+		return schema_types
+	elseif schema_types ~= nil then
+		error("schema has unsupported 'type' property")
+	elseif schema.properties then
+		return "object"
+	elseif schema.items then
+		return "array"
+	end
+	return "string"
+end
+
 local function unpack_propschema(propschema, propname, current_ns)
 
 	local proptype = "string"
@@ -49,9 +64,9 @@
 	local enums
 
 	if type(propschema) == "table" then
-		proptype = propschema.type
+		proptype = guess_schema_type(propschema);
 	elseif type(propschema) == "string" then
-		proptype = propschema
+		error("schema as string is not supported: " .. propschema .. " {" .. current_ns .. "}" .. propname)
 	end
 
 	if proptype == "object" or proptype == "array" then
@@ -209,9 +224,10 @@
 end
 
 local function parse(schema, s)
-	if schema.type == "object" then
+	local s_type = guess_schema_type(schema)
+	if s_type == "object" then
 		return parse_object(schema, s, schema)
-	elseif schema.type == "array" then
+	elseif s_type == "array" then
 		return parse_array(schema, s, schema)
 	else
 		error("top-level scalars unsupported")
@@ -306,7 +322,8 @@
 
 	local out = ctx or st.stanza(current_name, {xmlns = current_ns})
 
-	if schema.type == "object" then
+	local s_type = guess_schema_type(schema)
+	if s_type == "object" then
 
 		for prop, propschema in pairs(schema.properties) do
 			propschema = resolve_schema(propschema, root)
@@ -319,7 +336,7 @@
 		end
 		return out
 
-	elseif schema.type == "array" then
+	elseif s_type == "array" then
 		local itemschema = resolve_schema(schema.items, root)
 		local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(itemschema, current_name, current_ns)
 		for _, item in ipairs(t) do