util.jsonschema: Fix validation to not assume presence of "type" field

MattJ reported a curious issue where validation did not work as
expected. Primarily that the "type" field was expected to be mandatory,
and thus leaving it out would result in no checks being performed.
This was likely caused by misreading during initial development.

Spent some time testing against
https://github.com/json-schema-org/JSON-Schema-Test-Suite.git and
discovered a multitude of issues, far too many to bother splitting into
separate commits.

More than half of them fail. Many because of features not implemented,
which have been marked NYI. For example, some require deep comparisons
e.g. when objects or arrays are present in enums fields.

Some because of quirks with how Lua differs from JavaScript, e.g. no
distinct array or object types. Tests involving fractional floating
point numbers. We're definitely not going to follow references to remote
resources. Or deal with UTF-16 sillyness. One test asserted that 1.0 is
an integer, where Lua 5.3+ will disagree.

1 files changed, 141 insertions, 135 deletions

diff --git a/util/jsonschema.lua b/util/jsonschema.lua
index 8286fa19..48a3351f 100644
--- a/util/jsonschema.lua
+++ b/util/jsonschema.lua
@@ -1,3 +1,5 @@
+-- This file is generated from teal-src/util/jsonschema.lua
+
 local m_type = math.type or function (n)
 	return n % 1 == 0 and n <= 9007199254740992 and n >= -9007199254740992 and "integer" or "float";
 end;
@@ -10,12 +12,12 @@ local json_type_name = json.json_type_name
 
 local schema_t = {}
 
-local json_schema_object = {xml_t = {}}
-
-local type_validators = {}
+local json_schema_object = { xml_t = {} }
 
 local function simple_validate(schema, data)
-	if schema == "object" and type(data) == "table" then
+	if schema == nil then
+		return true
+	elseif schema == "object" and type(data) == "table" then
 		return type(data) == "table" and (next(data) == nil or type((next(data, nil))) == "string")
 	elseif schema == "array" and type(data) == "table" then
 		return type(data) == "table" and (next(data) == nil or type((next(data, nil))) == "number")
@@ -23,143 +25,169 @@ local function simple_validate(schema, data)
 		return m_type(data) == schema
 	elseif schema == "null" then
 		return data == null
+	elseif type(schema) == "table" then
+		for _, one in ipairs(schema) do
+			if simple_validate(one, data) then
+				return true
+			end
+		end
+		return false
 	else
 		return type(data) == schema
 	end
 end
 
-type_validators.string = function(schema, data)
+local complex_validate
 
-	if type(data) == "string" then
-		if schema.maxLength and #data > schema.maxLength then
-			return false
-		end
-		if schema.minLength and #data < schema.minLength then
-			return false
-		end
-		return true
+local function validate(schema, data, root)
+	if type(schema) == "boolean" then
+		return schema
+	else
+		return complex_validate(schema, data, root)
 	end
-	return false
 end
 
-type_validators.number = function(schema, data)
-	if schema.multipleOf and data % schema.multipleOf ~= 0 then
-		return false
-	end
+function complex_validate(schema, data, root)
 
-	if schema.maximum and not (data <= schema.maximum) then
-		return false
+	if root == nil then
+		root = schema
 	end
 
-	if schema.exclusiveMaximum and not (data < schema.exclusiveMaximum) then
-		return false
+	if schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
+		local referenced = pointer.resolve(root, schema["$ref"]:sub(2))
+		if referenced ~= nil and referenced ~= root and referenced ~= schema then
+			if not validate(referenced, data, root) then
+				return false
+			end
+		end
 	end
 
-	if schema.minimum and not (data >= schema.minimum) then
+	if not simple_validate(schema.type, data) then
 		return false
 	end
 
-	if schema.exclusiveMinimum and not (data > schema.exclusiveMinimum) then
-		return false
+	if schema.type == "object" then
+		if type(data) == "table" then
+
+			for k in pairs(data) do
+				if not (type(k) == "string") then
+					return false
+				end
+			end
+		end
 	end
 
-	return true
-end
+	if schema.type == "array" then
+		if type(data) == "table" then
 
-type_validators.integer = type_validators.number
+			for i in pairs(data) do
+				if not (math.type(i) == "integer") then
+					return false
+				end
+			end
+		end
+	end
 
-local function validate(schema, data, root)
-	if type(schema) == "boolean" then
-		return schema
+	if schema["enum"] ~= nil then
+		local match = false
+		for _, v in ipairs(schema["enum"]) do
+			if v == data then
+
+				match = true
+				break
+			end
+		end
+		if not match then
+			return false
+		end
 	end
-	if type(schema) == "string" then
-		return simple_validate(schema, data)
+
+	if type(data) == "string" then
+		if schema.maxLength and #data > schema.maxLength then
+			return false
+		end
+		if schema.minLength and #data < schema.minLength then
+			return false
+		end
 	end
-	if type(schema) == "table" then
-		if root == nil then
-			root = schema
+
+	if type(data) == "number" then
+		if schema.multipleOf and (data == 0 or data % schema.multipleOf ~= 0) then
+			return false
 		end
-		if schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then
-			local referenced = pointer.resolve(root, schema["$ref"]:sub(2))
-			if referenced ~= nil then
-				return validate(referenced, data, root)
-			end
+
+		if schema.maximum and not (data <= schema.maximum) then
+			return false
 		end
 
-		if schema.allOf then
-			for _, sub in ipairs(schema.allOf) do
-				if not validate(sub, data, root) then
-					return false
-				end
-			end
-			return true
+		if schema.exclusiveMaximum and not (data < schema.exclusiveMaximum) then
+			return false
 		end
 
-		if schema.oneOf then
-			local valid = 0
-			for _, sub in ipairs(schema.oneOf) do
-				if validate(sub, data, root) then
-					valid = valid + 1
-				end
-			end
-			return valid == 1
+		if schema.minimum and not (data >= schema.minimum) then
+			return false
 		end
 
-		if schema.anyOf then
-			for _, sub in ipairs(schema.anyOf) do
-				if validate(sub, data, root) then
-					return true
-				end
-			end
+		if schema.exclusiveMinimum and not (data > schema.exclusiveMinimum) then
 			return false
 		end
+	end
 
-		if schema["not"] then
-			if validate(schema["not"], data, root) then
+	if schema.allOf then
+		for _, sub in ipairs(schema.allOf) do
+			if not validate(sub, data, root) then
 				return false
 			end
 		end
+	end
 
-		if schema["if"] then
-			if validate(schema["if"], data, root) then
-				if schema["then"] then
-					return validate(schema["then"], data, root)
-				end
-			else
-				if schema["else"] then
-					return validate(schema["else"], data, root)
-				end
+	if schema.oneOf then
+		local valid = 0
+		for _, sub in ipairs(schema.oneOf) do
+			if validate(sub, data, root) then
+				valid = valid + 1
 			end
 		end
-
-		if schema.const ~= nil and schema.const ~= data then
+		if valid ~= 1 then
 			return false
 		end
+	end
 
-		if schema["enum"] ~= nil then
-			for _, v in ipairs(schema["enum"]) do
-				if v == data then
-					return true
-				end
+	if schema.anyOf then
+		local match = false
+		for _, sub in ipairs(schema.anyOf) do
+			if validate(sub, data, root) then
+				match = true
+				break
 			end
+		end
+		if not match then
 			return false
 		end
+	end
 
-		if schema.type then
-			if not simple_validate(schema.type, data) then
-				return false
-			end
+	if schema["not"] then
+		if validate(schema["not"], data, root) then
+			return false
+		end
+	end
 
-			local validator = type_validators[schema.type]
-			if validator then
-				return validator(schema, data, root)
+	if schema["if"] ~= nil then
+		if validate(schema["if"], data, root) then
+			if schema["then"] then
+				return validate(schema["then"], data, root)
+			end
+		else
+			if schema["else"] then
+				return validate(schema["else"], data, root)
 			end
 		end
-		return true
 	end
-end
 
-type_validators.table = function(schema, data, root)
+	if schema.const ~= nil and schema.const ~= data then
+		return false
+	end
+
 	if type(data) == "table" then
 
 		if schema.maxItems and #data > schema.maxItems then
@@ -178,24 +206,28 @@ type_validators.table = function(schema, data, root)
 			end
 		end
 
-		if schema.properties then
-			local additional = schema.additionalProperties or true
-			for k, v in pairs(data) do
-				if schema.propertyNames and not validate(schema.propertyNames, k, root) then
+		if schema.propertyNames ~= nil then
+			for k in pairs(data) do
+				if not validate(schema.propertyNames, k, root) then
 					return false
 				end
-				local s = schema.properties[k] or additional
-				if not validate(s, v, root) then
+			end
+		end
+
+		if schema.properties then
+			for k, sub in pairs(schema.properties) do
+				if data[k] ~= nil and not validate(sub, data[k], root) then
 					return false
 				end
 			end
-		elseif schema.additionalProperties then
+		end
+
+		if schema.additionalProperties ~= nil then
 			for k, v in pairs(data) do
-				if schema.propertyNames and not validate(schema.propertyNames, k, root) then
-					return false
-				end
-				if not validate(schema.additionalProperties, v, root) then
-					return false
+				if schema.properties == nil or schema.properties[k] == nil then
+					if not validate(schema.additionalProperties, v, root) then
+						return false
+					end
 				end
 			end
 		end
@@ -212,9 +244,11 @@ type_validators.table = function(schema, data, root)
 		end
 
 		local p = 0
-		if schema.prefixItems then
+		if schema.prefixItems ~= nil then
 			for i, s in ipairs(schema.prefixItems) do
-				if validate(s, data[i], root) then
+				if data[i] == nil then
+					break
+				elseif validate(s, data[i], root) then
 					p = i
 				else
 					return false
@@ -222,7 +256,7 @@ type_validators.table = function(schema, data, root)
 			end
 		end
 
-		if schema.items then
+		if schema.items ~= nil then
 			for i = p + 1, #data do
 				if not validate(schema.items, data[i], root) then
 					return false
@@ -230,7 +264,7 @@ type_validators.table = function(schema, data, root)
 			end
 		end
 
-		if schema.contains then
+		if schema.contains ~= nil then
 			local found = false
 			for i = 1, #data do
 				if validate(schema.contains, data[i], root) then
@@ -242,37 +276,9 @@ type_validators.table = function(schema, data, root)
 				return false
 			end
 		end
-
-		return true
 	end
-	return false
-end
 
-type_validators.object = function(schema, data, root)
-	if type(data) == "table" then
-		for k in pairs(data) do
-			if not (type(k) == "string") then
-				return false
-			end
-		end
-
-		return type_validators.table(schema, data, root)
-	end
-	return false
-end
-
-type_validators.array = function(schema, data, root)
-	if type(data) == "table" then
-
-		for i in pairs(data) do
-			if not (type(i) == "number") then
-				return false
-			end
-		end
-
-		return type_validators.table(schema, data, root)
-	end
-	return false
+	return true
 end
 
 json_schema_object.validate = validate;