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1'use strict'
2
3function isArguments (thingy) {
4  return thingy != null && typeof thingy === 'object' && thingy.hasOwnProperty('callee')
5}
6
7var types = {
8  '*': {label: 'any', check: function () { return true }},
9  A: {label: 'array', check: function (thingy) { return Array.isArray(thingy) || isArguments(thingy) }},
10  S: {label: 'string', check: function (thingy) { return typeof thingy === 'string' }},
11  N: {label: 'number', check: function (thingy) { return typeof thingy === 'number' }},
12  F: {label: 'function', check: function (thingy) { return typeof thingy === 'function' }},
13  O: {label: 'object', check: function (thingy) { return typeof thingy === 'object' && thingy != null && !types.A.check(thingy) && !types.E.check(thingy) }},
14  B: {label: 'boolean', check: function (thingy) { return typeof thingy === 'boolean' }},
15  E: {label: 'error', check: function (thingy) { return thingy instanceof Error }},
16  Z: {label: 'null', check: function (thingy) { return thingy == null }}
17}
18
19function addSchema (schema, arity) {
20  var group = arity[schema.length] = arity[schema.length] || []
21  if (group.indexOf(schema) === -1) group.push(schema)
22}
23
24var validate = module.exports = function (rawSchemas, args) {
25  if (arguments.length !== 2) throw wrongNumberOfArgs(['SA'], arguments.length)
26  if (!rawSchemas) throw missingRequiredArg(0, 'rawSchemas')
27  if (!args) throw missingRequiredArg(1, 'args')
28  if (!types.S.check(rawSchemas)) throw invalidType(0, ['string'], rawSchemas)
29  if (!types.A.check(args)) throw invalidType(1, ['array'], args)
30  var schemas = rawSchemas.split('|')
31  var arity = {}
32
33  schemas.forEach(function (schema) {
34    for (var ii = 0; ii < schema.length; ++ii) {
35      var type = schema[ii]
36      if (!types[type]) throw unknownType(ii, type)
37    }
38    if (/E.*E/.test(schema)) throw moreThanOneError(schema)
39    addSchema(schema, arity)
40    if (/E/.test(schema)) {
41      addSchema(schema.replace(/E.*$/, 'E'), arity)
42      addSchema(schema.replace(/E/, 'Z'), arity)
43      if (schema.length === 1) addSchema('', arity)
44    }
45  })
46  var matching = arity[args.length]
47  if (!matching) {
48    throw wrongNumberOfArgs(Object.keys(arity), args.length)
49  }
50  for (var ii = 0; ii < args.length; ++ii) {
51    var newMatching = matching.filter(function (schema) {
52      var type = schema[ii]
53      var typeCheck = types[type].check
54      return typeCheck(args[ii])
55    })
56    if (!newMatching.length) {
57      var labels = matching.map(function (schema) {
58        return types[schema[ii]].label
59      }).filter(function (schema) { return schema != null })
60      throw invalidType(ii, labels, args[ii])
61    }
62    matching = newMatching
63  }
64}
65
66function missingRequiredArg (num) {
67  return newException('EMISSINGARG', 'Missing required argument #' + (num + 1))
68}
69
70function unknownType (num, type) {
71  return newException('EUNKNOWNTYPE', 'Unknown type ' + type + ' in argument #' + (num + 1))
72}
73
74function invalidType (num, expectedTypes, value) {
75  var valueType
76  Object.keys(types).forEach(function (typeCode) {
77    if (types[typeCode].check(value)) valueType = types[typeCode].label
78  })
79  return newException('EINVALIDTYPE', 'Argument #' + (num + 1) + ': Expected ' +
80    englishList(expectedTypes) + ' but got ' + valueType)
81}
82
83function englishList (list) {
84  return list.join(', ').replace(/, ([^,]+)$/, ' or $1')
85}
86
87function wrongNumberOfArgs (expected, got) {
88  var english = englishList(expected)
89  var args = expected.every(function (ex) { return ex.length === 1 })
90    ? 'argument'
91    : 'arguments'
92  return newException('EWRONGARGCOUNT', 'Expected ' + english + ' ' + args + ' but got ' + got)
93}
94
95function moreThanOneError (schema) {
96  return newException('ETOOMANYERRORTYPES',
97    'Only one error type per argument signature is allowed, more than one found in "' + schema + '"')
98}
99
100function newException (code, msg) {
101  var e = new Error(msg)
102  e.code = code
103  if (Error.captureStackTrace) Error.captureStackTrace(e, validate)
104  return e
105}
106