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Diffstat (limited to 'teal-src/util/jsonschema.tl')
| -rw-r--r-- | teal-src/util/jsonschema.tl | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/teal-src/util/jsonschema.tl b/teal-src/util/jsonschema.tl new file mode 100644 index 00000000..1f731781 --- /dev/null +++ b/teal-src/util/jsonschema.tl @@ -0,0 +1,355 @@ +-- Copyright (C) 2021 Kim Alvefur +-- +-- This project is MIT/X11 licensed. Please see the +-- COPYING file in the source package for more information. +-- +-- Based on +-- https://json-schema.org/draft/2020-12/json-schema-core.html +-- https://json-schema.org/draft/2020-12/json-schema-validation.html +-- + +local json = require"util.json" +local null = json.null; + +local type json_type_name = json.json_type_name + +-- json_type_name here is non-standard +local type schema_t = boolean | json_type_name | json_schema_object + +local record json_schema_object + type json_type_name = json.json_type_name + type schema_object = json_schema_object + + type : json_type_name + enum : { any } + const : any + + allOf : { schema_t } + anyOf : { schema_t } + oneOf : { schema_t } + + ["not"] : schema_t + ["if"] : schema_t + ["then"] : schema_t + ["else"] : schema_t + + -- numbers + multipleOf : number + maximum : number + exclusiveMaximum : number + minimum : number + exclusiveMinimum : number + + -- strings + maxLength : integer + minLength : integer + pattern : string + format : string + + -- arrays + prefixItems : { schema_t } + items : schema_t + contains : schema_t + maxItems : integer + minItems : integer + uniqueItems : boolean + maxContains : integer + minContains : integer + + -- objects + properties : { string : schema_t } + maxProperties : integer + minProperties : integer + required : { string } + dependentRequired : { string : { string } } + additionalProperties: schema_t + patternProperties: schema_t + propertyNames : schema_t + + -- xml + record xml_t + name : string + namespace : string + prefix : string + attribute : boolean + wrapped : boolean + + -- nonstantard, maybe in the future + text : boolean + x_name_is_value : boolean + x_single_attribute : string + end + + xml : xml_t + + -- descriptive + title : string + description : string + deprecated : boolean + readOnly : boolean + writeOnly : boolean + + -- methods + validate : function ( schema_t, any) : boolean +end + +-- TODO validator function per schema property + +local type_validators : { json_type_name : function (schema_t, any) : boolean } = {} + +local function simple_validate(schema : json_type_name, data : any) : boolean + if schema == "object" and data is table then + return type(data) == "table" and (next(data)==nil or type((next(data, nil))) == "string") + elseif schema == "array" and data is table then + return type(data) == "table" and (next(data)==nil or type((next(data, nil))) == "number") + elseif schema == "integer" then + return math.type(data) == schema + elseif schema == "null" then + return data == null + else + return type(data) == schema + end +end + +type_validators.string = function (schema : json_schema_object, data : any) : boolean + -- XXX this is measured in byte, while JSON measures in ... bork + -- TODO use utf8.len? + if data is 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 + end + return false +end + +type_validators.number = function (schema : json_schema_object, data : number) : boolean + if schema.multipleOf and data % schema.multipleOf ~= 0 then + return false + end + + if schema.maximum and not ( data <= schema.maximum ) then + return false + end + + if schema.exclusiveMaximum and not ( data < schema.exclusiveMaximum ) then + return false + end + + if schema.minimum and not ( data >= schema.minimum ) then + return false + end + + if schema.exclusiveMinimum and not ( data > schema.exclusiveMinimum ) then + return false + end + + return true +end + +type_validators.integer = type_validators.number + +local function validate(schema : schema_t, data : any) : boolean + if schema is boolean then + return schema + end + if schema is json_type_name then + return simple_validate(schema, data) + end + if schema is json_schema_object then + if schema.allOf then + for _, sub in ipairs(schema.allOf) do + if not validate(sub, data) then + return false + end + end + return true + end + + if schema.oneOf then + local valid = 0 + for _, sub in ipairs(schema.oneOf) do + if validate(sub, data) then + valid = valid + 1 + end + end + return valid == 1 + end + + if schema.anyOf then + for _, sub in ipairs(schema.anyOf) do + if validate(sub, data) then + return true + end + end + return false + end + + if schema["not"] then + if validate(schema["not"], data) then + return false + end + end + + if schema["if"] then + if validate(schema["if"], data) then + if schema["then"] then + return validate(schema["then"], data) + end + else + if schema["else"] then + return validate(schema["else"], data) + end + end + end + + if schema.const ~= nil and schema.const ~= data then + return false + end + + if schema["enum"] ~= nil then + for _, v in ipairs(schema["enum"]) do + if v == data then + return true + end + end + return false + end + + if schema.type then + if not simple_validate(schema.type, data) then + return false + end + + local validator = type_validators[schema.type] + if validator then + return validator(schema, data) + end + end + return true + end +end + +type_validators.table = function (schema : json_schema_object, data : any) : boolean + if data is table then + + if schema.maxItems and #data > schema.maxItems then + return false + end + + if schema.minItems and #data < schema.minItems then + return false + end + + if schema.required then + for _, k in ipairs(schema.required) do + if data[k] == nil then + return false + end + end + end + + if schema.properties then + local additional : schema_t = schema.additionalProperties or true + for k, v in pairs(data) do + if schema.propertyNames and not validate(schema.propertyNames, k) then + return false + end + local s = schema.properties[k as string] or additional + if not validate(s, v) then + return false + end + end + elseif schema.additionalProperties then + for k, v in pairs(data) do + if schema.propertyNames and not validate(schema.propertyNames, k) then + return false + end + if not validate(schema.additionalProperties, v) then + return false + end + end + end + + if schema.uniqueItems then + -- only works for scalars, would need to deep-compare for objects/arrays/tables + local values : { any : boolean } = {} + for _, v in pairs(data) do + if values[v] then + return false + end + values[v] = true + end + end + + local p = 0 + if schema.prefixItems then + for i, s in ipairs(schema.prefixItems) do + if validate(s, data[i]) then + p = i + else + return false + end + end + end + + if schema.items then + for i = p+1, #data do + if not validate(schema.items, data[i]) then + return false + end + end + end + + if schema.contains then + local found = false + for i = 1, #data do + if validate(schema.contains, data[i]) then + found = true + break + end + end + if not found then + return false + end + end + + return true + end + return false +end + +type_validators.object = function (schema : schema_t, data : any) : boolean + if data is table then + for k in pairs(data) do + if not k is string then + return false + end + end + + return type_validators.table(schema, data) + end + return false +end + +type_validators.array = function (schema : schema_t, data : any) : boolean + if data is table then + + -- just check that there the keys are all numbers + for i in pairs(data) do + if not i is number then + return false + end + end + + return type_validators.table(schema, data) + end + return false +end + +json_schema_object.validate = validate; + +return json_schema_object; |