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.
For the latest stable version, run:
# 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 [email protected]
# 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 [email protected]
# 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 [email protected]
# 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 [email protected]
Set the importHelpers compiler option on the command line:
tsc --importHelpers file.ts
or in your tsconfig.json:
{
"compilerOptions": {
"importHelpers": true
}
}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/[email protected]/tslib.d.ts"]
}
}
}- Run the Bump tslib GitHub workflow and choose patch, minor, or major
- Review and squash-merge the generated version-bump PR
- The release runs automatically: tag, build, publish to npm, and create a GitHub release with generated notes
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.