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106 lines
3.6 KiB
JavaScript

'use strict'
module.exports = validate
function isArguments (thingy) {
return thingy != null && typeof thingy === 'object' && thingy.hasOwnProperty('callee')
}
const types = {
'*': {label: 'any', check: () => true},
A: {label: 'array', check: _ => Array.isArray(_) || isArguments(_)},
S: {label: 'string', check: _ => typeof _ === 'string'},
N: {label: 'number', check: _ => typeof _ === 'number'},
F: {label: 'function', check: _ => typeof _ === 'function'},
O: {label: 'object', check: _ => typeof _ === 'object' && _ != null && !types.A.check(_) && !types.E.check(_)},
B: {label: 'boolean', check: _ => typeof _ === 'boolean'},
E: {label: 'error', check: _ => _ instanceof Error},
Z: {label: 'null', check: _ => _ == null}
}
function addSchema (schema, arity) {
const group = arity[schema.length] = arity[schema.length] || []
if (group.indexOf(schema) === -1) group.push(schema)
}
function validate (rawSchemas, args) {
if (arguments.length !== 2) throw wrongNumberOfArgs(['SA'], arguments.length)
if (!rawSchemas) throw missingRequiredArg(0, 'rawSchemas')
if (!args) throw missingRequiredArg(1, 'args')
if (!types.S.check(rawSchemas)) throw invalidType(0, ['string'], rawSchemas)
if (!types.A.check(args)) throw invalidType(1, ['array'], args)
const schemas = rawSchemas.split('|')
const arity = {}
schemas.forEach(schema => {
for (let ii = 0; ii < schema.length; ++ii) {
const type = schema[ii]
if (!types[type]) throw unknownType(ii, type)
}
if (/E.*E/.test(schema)) throw moreThanOneError(schema)
addSchema(schema, arity)
if (/E/.test(schema)) {
addSchema(schema.replace(/E.*$/, 'E'), arity)
addSchema(schema.replace(/E/, 'Z'), arity)
if (schema.length === 1) addSchema('', arity)
}
})
let matching = arity[args.length]
if (!matching) {
throw wrongNumberOfArgs(Object.keys(arity), args.length)
}
for (let ii = 0; ii < args.length; ++ii) {
let newMatching = matching.filter(schema => {
const type = schema[ii]
const typeCheck = types[type].check
return typeCheck(args[ii])
})
if (!newMatching.length) {
const labels = matching.map(_ => types[_[ii]].label).filter(_ => _ != null)
throw invalidType(ii, labels, args[ii])
}
matching = newMatching
}
}
function missingRequiredArg (num) {
return newException('EMISSINGARG', 'Missing required argument #' + (num + 1))
}
function unknownType (num, type) {
return newException('EUNKNOWNTYPE', 'Unknown type ' + type + ' in argument #' + (num + 1))
}
function invalidType (num, expectedTypes, value) {
let valueType
Object.keys(types).forEach(typeCode => {
if (types[typeCode].check(value)) valueType = types[typeCode].label
})
return newException('EINVALIDTYPE', 'Argument #' + (num + 1) + ': Expected ' +
englishList(expectedTypes) + ' but got ' + valueType)
}
function englishList (list) {
return list.join(', ').replace(/, ([^,]+)$/, ' or $1')
}
function wrongNumberOfArgs (expected, got) {
const english = englishList(expected)
const args = expected.every(ex => ex.length === 1)
? 'argument'
: 'arguments'
return newException('EWRONGARGCOUNT', 'Expected ' + english + ' ' + args + ' but got ' + got)
}
function moreThanOneError (schema) {
return newException('ETOOMANYERRORTYPES',
'Only one error type per argument signature is allowed, more than one found in "' + schema + '"')
}
function newException (code, msg) {
const err = new Error(msg)
err.code = code
/* istanbul ignore else */
if (Error.captureStackTrace) Error.captureStackTrace(err, validate)
return err
}