reflect-ts

• TypeScript reflect library
• TypeScript can not acquire type information at runtime.
• In this library, type information can be handled easily at run time by generating TypeScript type from type information.

TypeScript

• 3.0.1+

Install

$ npm i reflect-ts

Example

import * as R from "reflect-ts";

// make TypeData
// Do not write type annotations and generics
const typeData = R.union(R.obj({
    type: R.strl("tweet"),
    text: R.str,
    likeUsers: R.arr(R.str)
}), R.obj({
    type: R.strl("retweet"),
    retweetID: R.str,
}));

// Generate TypeScript-Type from TypeData
/*
type Type = {
    type: "tweet",
    text: string,
    likeUsers: string[]
} | {
    type: "retweet",
    retweetID: string
};
*/
type Type = R.ToType<typeof typeData>;

const tweet: Type = {
    type: "tweet",
    text: "Hello reflect-ts",
    likeUsers: ["user1", "user2"]
};

const retweet: Type = {
    type: "retweet",
    retweetID: "tweet1"
};

function reflect(type: R.TypeData) {
    console.log(type);
}

reflect(typeData);

Usage

TypeData

generator	type	type data
bool	boolean	{type:"boolean"}
num	number	{type:"number"}
str	string	{type:"string"}
arr(typeData)	T[]	{type:"array",value:TypeData}
tuple(...typeData)	[...T]	{type:"tuple",values:TypeData[]}
any	any	{type:"any"}
nil	null	{type:"null"}
undef	undefined	{type:"undefined"}
symbol	symbol	{type:"symbol"}
obj({x:typeData...})	{x:T...}	{type:"object",values:{[key:string]:TypeData}}
objMap(typeData)	{[key:string]:T}	{type:"object_map",value:TypeData}
union(...typeData)	A|B|...	{type:"union",values:TypeData[]}
inter(...typeData)	A&B&...	{type:"intersection",values:TypeData[]}
strl(str)	"xxx"	{type:"string_literal",value:string}
numl(num)	1	{type:"number_literal",value:number}
booll(bool)	true	{type:"boolean_literal",value:boolean}