forked from joel-simon/easy-types
-
Notifications
You must be signed in to change notification settings - Fork 1
/
index.js
184 lines (170 loc) · 4.56 KB
/
index.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
var primitives = ['boolean', 'number', 'undefined', 'string', 'object'];
var canOverwriteTypes = false;
var types = {
posInt: function(i) {
return ((typeof i === 'number') && (i % 1 === 0) && (i >= 0));
},
int: function(i) {
return ((typeof i === 'number') && (i % 1 === 0));
},
date: function(d) {
return Object.prototype.toString.call(d) === '[object Date]';
},
array: function(a) {
return Array.isArray(a);
},
null: function(e) {
return e === null;
},
object: function(obj) {
return typeof obj === 'object';
},
buffer: function(b) {
return Buffer.isBuffer(b);
}
};
function pretty(obj) {
var serialized;
try {
serialized = JSON.stringify(obj, null, 2);
} catch(e) {
serialized = 'object';
}
return serialized;
}
var userTypes = {};
function is(obj, type) {
switch (typeof type) {
// Check for constructor, or arbitrary function to apply to obj
case 'function':
if (obj instanceof type) { return; }
var result;
try {
result = type(obj);
} catch(e) {
throw new Error (pretty(obj) + ' failed ' + type);
}
if (result === false) throw new Error(pretty(obj) + ' failed ' + type);
break;
case 'string':
// optional types
var optType = type.charAt(type.length - 1) === '?' ?
type.slice(0, -1) :
undefined;
// success if optional type and undefined value
if (optType) {
if (obj === undefined) return;
type = optType;
}
// user defined types
if (userTypes[type]) {
is(obj, userTypes[type]);
}
// default types
else if (types[type]) {
if (!types[type](obj)) {
throw new Error(pretty(obj) + ' should be a ' + pretty(type));
}
}
// arrays : "[type]"
else if (type.charAt(0) === '[' &&
type.charAt(type.length-1) === ']') {
var typeName = type.slice(1, -1);
var checkType = userTypes[typeName] || types[typeName] ||
(primitives.indexOf(typeName) !== -1 && typeName);
// if not a known type and not an optional type, then pass thru
if (!checkType) { checkType = typeName; }
if (!Array.isArray(obj)) {
throw new Error(pretty(obj) +
' should be an array of ' + typeName);
}
if (obj.length === 0) {
return;
}
for (var i = 0; i < obj.length; i++) {
is(obj[i], checkType);
}
}
// primitive types
else if (typeof(obj) !== type) {
throw new Error(pretty(obj) + ' should be ' + type);
}
break;
case 'object':
if (typeof obj !== 'object') {
throw new Error(pretty(obj) + ' should be an object');
}
if (obj === null) {
throw new Error(pretty(obj) + ' is not of type ' + pretty(type));
}
// {} case
for (var e in type) {
if (!type.hasOwnProperty(e)) { continue; }
if (typeof obj[e] === undefined && type[e].charAt &&
type[e].charAt(type[e].length - 1) !== '?') {
throw new Error(pretty(obj) + ' does not contain field ' + e +
' for requirement ' + pretty(type));
}
is(obj[e], type[e]);
}
break;
default:
throw new Error('Not a valid requirement: ' + pretty(type) +
' for ' + pretty(obj));
}
}
function check(obj) {
return {
is: function(type, msg) {
try {
is(obj, type);
} catch(e) {
console.error(e.stack);
if (msg) { throw new Error(msg); }
throw new Error(pretty(obj) + ' is NOT ' + pretty(type));
}
return true;
},
isnot: function(type, msg) {
var isIt = true;
try {
is(obj, type);
} catch(e) {
isIt = false;
}
if (isIt) {
if (msg) { throw new Error(msg); }
throw new Error(pretty(obj) + ' IS ' + pretty(type));
}
}
};
}
function addType(key, checker) {
check(key).is('string');
if (!canOverwriteTypes) {
check(userTypes[key]).is('undefined',
'Overwriting existing types not allowed: ' + key);
}
userTypes[key] = checker;
return check;
}
function addTypes(obj) {
check(obj).is('object');
for (var key in obj) {
if (obj.hasOwnProperty(key)) {
addType(key, obj[key]);
}
}
return check;
}
function clearTypes() {
userTypes = {};
}
function allowOverwritingTypes() {
canOverwriteTypes = true;
}
check.addType = addType;
check.addTypes = addTypes;
check.clearTypes = clearTypes;
check.allowOverwritingTypes = allowOverwritingTypes;
module.exports = check;