tslib

This is a runtime library for TypeScript that contains all of the TypeScript helper functions.

This library is primarily used by the `--importHelpers` flag in TypeScript. When using `--importHelpers`, a module that uses helper functions like `__extends` and `__assign` in the following emitted file:

var __assign = (this && this.__assign) || Object.assign || function(t) {
for (var s, i = 1, n = arguments.length; i < n; i++) {
s = arguments[i];
for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
t[p] = s[p];
}
return t;
};
exports.x = {};
exports.y = __assign({}, exports.x);

will instead be emitted as something like the following:

var tslib_1 = require("tslib");
exports.x = {};
exports.y = tslib_1.__assign({}, exports.x);

Because this can avoid duplicate declarations of things like `__extends`, `__assign`, etc., this means delivering users smaller files on average, as well as less runtime overhead. For optimized bundles with TypeScript, you should absolutely consider using `tslib` and `--importHelpers`.

# Installing

For the latest stable version, run:

## npm

# TypeScript 3.9.2 or later
npm install tslib
# TypeScript 3.8.4 or earlier
npm install tslib@^1
# TypeScript 2.3.2 or earlier
npm install tslib@1.6.1

## yarn

# TypeScript 3.9.2 or later
yarn add tslib
# TypeScript 3.8.4 or earlier
yarn add tslib@^1
# TypeScript 2.3.2 or earlier
yarn add tslib@1.6.1

## bower

# TypeScript 3.9.2 or later
bower install tslib
# TypeScript 3.8.4 or earlier
bower install tslib@^1
# TypeScript 2.3.2 or earlier
bower install tslib@1.6.1

## JSPM

# TypeScript 3.9.2 or later
jspm install tslib
# TypeScript 3.8.4 or earlier
jspm install tslib@^1
# TypeScript 2.3.2 or earlier
jspm install tslib@1.6.1

# Usage

Set the `importHelpers` compiler option on the command line:

tsc --importHelpers file.ts

or in your tsconfig.json:

{
"compilerOptions": {
"importHelpers": true
}
}

#### For bower and JSPM users

You will need to add a `paths` mapping for `tslib`, e.g. For Bower users:

{
"compilerOptions": {
"module": "amd",
"importHelpers": true,
"baseUrl": "./",
"paths": {
"tslib" : ["bower_components/tslib/tslib.d.ts"]
}
}
}

For JSPM users:

{
"compilerOptions": {
"module": "system",
"importHelpers": true,
"baseUrl": "./",
"paths": {
"tslib" : ["jspm_packages/npm/tslib@2.x.y/tslib.d.ts"]
}
}
}

# Contribute

There are many ways to contribute to TypeScript.

- Submit bugs and help us verify fixes as they are checked in.
- Review the source code changes.
- Engage with other TypeScript users and developers on StackOverflow.
- Join the #typescript discussion on Twitter.
- Contribute bug fixes.

# Documentation

- Quick tutorial
- Programming handbook
- Homepage