TypeChecker for JavaScript/Typescript

Author : lessu

Description
-----------
A flexable type checker.

tested under typescript 2.3.4 and 2.4.2, 2.8.1;
es5 is now supported

Installation

``
npm install ts-check --save
`




Test

mocha tests/index.js

Features

Flexable,easy-to-extend type checker for complex object.

example
` typescript
TypeChecker.checkType(sku,"SetSkuItem[]",{
SetSkuItem : {
key : "string",
stock : "number",
unit : "number",
price : "number",
cost_price : "number",
options : "ItemOptions[]"
},
   ItemOptions : {
filed_id : "number",
filed_options:["number","string"]
}
});
`


Update Log

- v0.2.3

1.New feature added : now we can get failed log message by access lastError variable.

2.Fix type error synax under typescript 2.8.1




Usage

$3


`
import * as TypeChecker from "ts-checker";
`

$3

Basic type include
`typescript
export enum BasicTypes{
number = "number",
string = "string",
object = "object",
any = "any",
null = "null",
undefined = "undefined"
}
`
Check basic types :
`typescript
TypeCheker.checkType(undefined,"undefined");

TypeCheker.checkType(null,"any");

TypeCheker.checkType(123,"number");

//Notice a string number is also a number type in weak Number mode;
TypeCheker.checkType("123","number",{},{weakNumber:true});

`

$3


any length
`typescript
assert(TypeCheker.checkType([1,2,3,4,5,6],"number[]"));
`

check length
`typescript
assert(TypeCheker.checkType([1,2,3],"number[3]"));
assert(!TypeCheker.checkType([1,2,3],"number[2]"));
`

array array
`typescript
assert(TypeCheker.checkType([[1],[2],[3]],"number[1][3]"));
assert(TypeCheker.checkType([[1],[2],[3]],"number[][3]"));
`

$3


Signature
`typescript
((value:any)=>boolean);
`
Usage
`typescript
TypeCheker.checkType( { a : "1" },(value)=>{
return typeof value["a"] == "string";
});
`

$3

`typescript
TypeCheker.checkType({a:"1"},{
a : "string"
});

TypeCheker.checkType({
a:"1",
b:{c:1},
c:{
d:{
e:1
}
}
},{
a : "string",
b : function(value:any){
return typeof value.c == "number";
},
c : {
d : {
e : "number"
}
}
});
`

$3

The checked value can be string, number or {a:number};

`typescript
TypeCheker.checkType({a:1},["string","number",{
a : "number"
}]);
`




$3


`typescript
//definedTypes is a {customType => check} object.
TypeCheker.checkType(value,type,definedTypes);
`

`typescript
TypeCheker.checkType(
//to check
{
biggerThan0 : 2
},
//type
{
biggerThan0 : ">0"
},
//custom type,define >0 as a custom type , and can be used in typeChecker
{
">0" : function( value : any ){
if(typeof value == "number"){
return value > 0;
}else{
return parseInt(value) > 0
}
}
});

//custom type can be nested
TypeCheker.checkType({
biggerThan0 : [1,2,3,4]
},{
biggerThan0 : ">0[]"
},{
">0" : function(value:any){
if(typeof value == "number"){
return value > 0;
}else{
return parseInt(value) > 0
}
}
});

//or a real life example
TypeChecker.checkType(sku,"SetSkuItem[]",{
SetSkuItem : {
key : "string",
stock : "number",
unit : "number",
price : "number",
cost_price : "number",
options : "ItemOptions[]"
},
   ItemOptions : {
filed_id : "number",
filed_options:["number","string"]
}
});
`

$3

If a DefinedType is a function, args are supported;

Notice,Args will be convert to pure string ; every , is recognized as a splitor,
So DO NOT call like CustomType(a,"1,2,3"), It will convert to
`typescript
[
"a",
"\"1",
"2",
"3\""
]
`

`typescript
assert(!
TypeCheker.checkType({
biggerThan0 : 6
},{
biggerThan0 : "range(0,5)"
},{
"range" : function(value:any,args:string[]){
if(args.length==0){
return false;
}else if(args.length == 1){
return value> parseFloat(args[0]);
}else{
return value >= parseFloat(args[0]) && value <= parseFloat(args[1]);
}
}
})
);
`

$3


Custom type can be add to default defaultDefinedChecker object;
so that can be used any where.
`typescript
TypeCheker.defaultDefinedChecker[">0"] = function(value:any){
if(typeof value == "number"){
return value > 0;
}else{
return parseInt(value) > 0
}
};
assert(TypeCheker.checkType({a:1},{a:">0"}));
assert(!TypeCheker.checkType({a:-1},{a:">0"}));
``

License

MIT