Error encountered after deploying Angular 4 application with Webpack 3 in a production environment

Question

Error encountered after deploying Angular 4 application with Webpack 3 in a production environment

Upon successfully building with angular4+webpack3, I encountered an error on the second refresh in the browser. The error message was:


uncaught exception: reflect-metadata shim is required when using class decorators

To resolve this issue, I had to add the following script to my index.html file:


 <script src="Reflect.js"></script>

Although this fixed the problem, I wondered why it was necessary to include this script in the index.html file. Shouldn't it be included in the webpack main.bundle.js instead?

angular typescript webpack

Answer 1

Answer №1

It appears that a polyfill is missing from your application. I personally recommend using core-js's polyfills for optimal performance.

Check out core-js on GitHub

Once you have installed the polyfill, there are various ways to integrate it into your project.

If you prefer using a polyfills entry point, simply include the following lines:

import "core-js/es6/reflect"
import "core-js/es7/reflect"

If you do not have a polyfills entry point, you can utilize the webpack ProvidePlugin instead. Update your webpack configuration with the following code snippet:

plugins: [
  ...
  new webpack.ProvidePlugin({
    Reflect: 'core-js/es7/reflect'
  })
  ...
]

Here is where I found the solution

Answer 2

It appears that a polyfill is missing from your application. I personally recommend using core-js's polyfills for optimal performance.

Check out core-js on GitHub

Once you have installed the polyfill, there are various ways to integrate it into your project.

If you prefer using a polyfills entry point, simply include the following lines:

import "core-js/es6/reflect"
import "core-js/es7/reflect"

If you do not have a polyfills entry point, you can utilize the webpack ProvidePlugin instead. Update your webpack configuration with the following code snippet:

plugins: [
  ...
  new webpack.ProvidePlugin({
    Reflect: 'core-js/es7/reflect'
  })
  ...
]

Here is where I found the solution

Error encountered after deploying Angular 4 application with Webpack 3 in a production environment

Answer №1

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