InversifyJS requires a modern JavaScript engine with support for the Promise, Map, Metadata Reflection API and Proxy objects. If your environment don't support one of these you will need to import a shim or polyfill.
⚠️ Thereflect-metadatapolyfill should be imported only once in your entire application because the Reflect object is mean to be a global singleton. More details about this can be found here.
Required always. Use reflect-metadata as polyfill.
$ npm install reflect-metadata
The type definitions for reflect-metadata are included in the npm package. You need to add the following
reference to the types field in your tsconfig.json:
"types": ["reflect-metadata"]
Finally, import reflect-metadata. If you are working in Node.js you can use:
import "reflect-metadata";
If you are working in a web browser you can use a script tag:
<script src="./node_modules/reflect-metadata/Reflect.js"></script>
This will create the Reflect object as a global.
Maps are required when using InversifyJS 3 or higher.
Most modern JavaScript engines support map but if you need to support old browsers you will need to use a map polyfill (e.g. es6-map).
Promises are required if you want to:
Inject a provider or inject dynamic values asynchronously.
Handle post construction and activation, or pre destroy and deactivation asynchronously.
Most modern JavaScript engines support promises but if you need to support old browsers you will need to use a promise polyfill (e.g. es6-promise or bluebird).
Proxies are only required only if you want to inject a proxy.
As today (September 2016) proxies are not very well supported and it is very likely that you will need to use a proxy polyfill. For example, we use harmony-proxy as polyfill to run our unit tests.