Runtime library for TypeScript helper functions
When working with TypeScript, using helper functions efficiently is crucial for maintaining clean and performant code. This is where tslib comes into play. tslib is a runtime library for TypeScript that encapsulates all of the TypeScript helper functions. By installing tslib via npm install tslib, developers can leverage these functions without duplicating them across different modules. This not only streamlines the development process but also ensures that the final bundled code is smaller and more optimized.
One of the primary benefits of using tslib is its compatibility with the --importHelpers flag in TypeScript. When this flag is enabled, TypeScript automatically imports necessary helper functions from tslib instead of embedding them directly into each file. This approach significantly reduces the file size of the emitted JavaScript, which in turn enhances performance. Smaller file sizes mean quicker load times and a better overall user experience, which are essential factors for SEO rankings.
Moreover, tslib ensures consistency across your TypeScript projects. Helper functions like __extends, __assign, and others are centralized within the tslib library, providing a uniform implementation that can be relied upon throughout your codebase. This not only makes your code cleaner and easier to maintain but also reduces the risk of bugs associated with duplicated or inconsistent helper functions.
Installing tslib is straightforward. With a simple command like npm install tslib, developers can integrate this powerful library into their projects. Whether you are using the latest TypeScript version or an older one, tslib supports various versions, ensuring that your projects can benefit from optimized helper functions regardless of your setup. By incorporating tslib, you can achieve more efficient, cleaner, and more maintainable TypeScript code, ultimately leading to better performance and higher SEO rankings for your web applications.
A README file for the tslib code repository. View Code
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 tslib@1.6.1
# 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
# 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
# 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
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/tslib@2.x.y/tslib.d.ts"]
}
}
}
package.json and bower.jsongit tag [version]git push --tagsDone.
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