Defines static typed DTO with strict runtime validation and user friendly error messages like:
npm install mol_data_allDefines static typed DTO with strict runtime validation and user friendly error messages like:
``
["friends"][0]["phone"] undefined is not any of variants
undefined is not a string
undefined is not a number
- $mol_data_boolean - boolean type
- $mol_data_number - number type
- $mol_data_integer - integer type
- $mol_data_range - range restriction
- $mol_data_string - string type
- $mol_data_pattern - string by pattern
- $mol_data_email - email string
- $mol_data_tagged - tagged primitive type
- $mol_data_nullable - nullable version of given type
- $mol_data_optional - optional version of given type
- $mol_data_variant - one of set of types
- $mol_data_const - deep equal to given value
- $mol_data_array - array of given type
- $mol_data_record - maps given fields to runtypes
- $mol_data_dict - dictionary maps string to given type
- $mol_data_enum - value of given enum
- $mol_data_instance - instance of class
- $mol_data_pipe - pipeline of runtypes
`typescript
// Base Type
const PersonDTO = $mol_data_record({
name : $mol_data_string ,
age : $mol_data_optional( $mol_data_integer ) ,
birthday : $mol_data_pipe( $mol_data_string , $mol_time_moment ) ,
})
// Derived Type
const UserDTO = $mol_data_record({
... PersonDTO.config,
phone: $mol_data_variant( $mol_data_string , $mol_data_integer ),
mail: $mol_data_email,
})
// Ensure this is a User
const jin = UserDTO({
name : 'Jin' ,
age : 33 ,
birthday : '1984-08-04T12:00:00Z' ,
phone : 791234567890,
mail : 'foo@example.org' ,
})
// typeof jin === {
// readonly name: string;
// readonly age?: number | undefined;
// readonly birthday: $mol_time_moment;
// readonly phone: string | number;
// readonly mail: string;
// }
// Allow only Users
function printName( user : typeof UserDTO.Value ) {
console.log( user.name )
}
printName( jin )
// Wrong json from server
const json = {
name : 'Jin' ,
age : 33 ,
birthday : '1984-08-04T12:00:00Z' ,
phone : 791234567890,
mail : '' , // !
} as any
// Runtime error: ["mail"] is not a /.+@.+/
printName( UserDTO( json ) )
`
`typescript
const { Weight, Length } = $mol_data_tagged({
Weight: $mol_data_integer,
Length: $mol_data_integer,
})
Length( 20 ) // Validate
let len = Length( 10 ) // Inferred type
let kg: typeof Weight.Value = Weight( 1000 ) // Explicit type
len = 20 // Implicit Cast
let num: number = len // Implicit Cast
len = Length( Weight( 20 ) ) // Explicit Cast
len = Weight( 20 ) // Compile time error
len = Length( 20.1 ) // Run time error
`
`typescript
const Duration = $mol_data_pipe(
$mol_data_variant(
$mol_data_string ,
$mol_data_integer ,
) ,
$mol_time_duration ,
)
JSON.stringify( Duration( 'P1D' ) ) // "P1DT"
JSON.stringify( Duration( 1000 ) ) // "PT1S"
`
`typescript${ val } have length less than 8
const Password = $mol_data_setup( ( val: string ) => {
const str = $mol_data_string( val )
if( str.length >= 8 ) return str
return $mol_fail(
new $mol_data_error( )
)
} )
Password( 123 ) // ❌ 123 is not a string
Password( 'qwerty' ) // ❌ qwerty have length less than 8
Password( 'qwertyuiop' ) // ✅
`
`typescript${ val } have length less than ${minLength}
const MinLength = ( minLength = 8 )=> $mol_data_setup( ( val: string ) => {
const str = $mol_data_string( val )
if( str.length >= minLength ) return str
return $mol_fail(
new $mol_data_error( )
)
}, minLength )
const Password = MinLength(8)
Password( 123 ) // ❌ 123 is not a string
Password( 'qwerty' ) // ❌ qwerty have length less than 8
Password( 'qwertyuiop' ) // ✅
`
`
npm install mol_data_all
`typescript
import {
$mol_data_tagged as Tagged,
$mol_data_integer as Integer,
} from "mol_data_all"
const { Age } = Tagged({ Age: Integer })
let age = Age( 17 )
age = Age( age + 1 )
``
- gcanti/io-ts - Runtime type system for IO decoding/encoding
- pelotom/runtypes - Runtime validation for static types
- vriad/zod - TypeScript-first schema validation with static type inference
- ianstormtaylor/superstruct - A simple and composable way to validate data in JavaScript (and TypeScript).