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Kudo Collector
Kudo Collector

How to add coreJS3 to pcf react to support browsers like IE11

I noticed that if you use es6 features like promises in pcf react, IE 11 will error.


How do you add "polyfills" like coreJS3 into a pcf react component? It would be ideal if we can use the babel-preset-env & babel-plugin-transform-runtime to do this.



Power Apps
Power Apps

@rexkenley - Polyfills for ES6 features that can't be transpiled down to ES5 should already be part of the hosting app platform, either model-driven or canvas PowerApps. For ES6 features that can be transpiled down to ES5, that should already be part of the out-of-the-box tooling build experience, as the base tsconfig file specifies a target of ES5 while allowing use of the ES6 syntax at development time.

Are you running into issues, or just trying to be proactive in understanding before getting started?



Thanks for the reply. I created a simple pcf-react project that works fine in chrome, but errors in IE11. I could be wrong with my assumption that it is a missing es6 polyfill issue.


Both browsers are running v9 Unified.

Chrome on left, ie11 on rightChrome on left, ie11 on right

You can find the source code at


Thanks for taking a look at this.



Is there a way to set the wepback mode to development and devtool inline-source-map so I can debug it in IE11?

Hi @rexkenley 

The UCI already has the bluebird promise polyfill so it's unlikely to be that.


It's more likely to be something like Object.assign.

Just to be sure - can you try adding the babel polyfill


You can require/import it at the top of the index.js/ts PCF entry point.


Also - check that there are no imports that you are using that have non-transpiled ES6 features.




Thanks for pointing me in the right direction Scott. I went ahead and change the webpack config to use my standard preset-env configuration.


          test: /\.(js|jsx)$/,
          exclude: /node_modules/,
          use: {
            options: {
              presets: [
                    targets: {
              plugins: [
                ["@babel/plugin-transform-runtime", { corejs3 }] // non global polyfills



Annotation 2019-10-25 131302.png


I think by adding corejs3 and @babel/plugin-transform-runtime, PCF react would have better support for ie11. The other benefit of this is that you don't have to add "polyfill" in your code, babel will handle that for you (although I am not sure if you have to specify the browser target to make the entire thing work).


const babelPlugins = [
  [require.resolve("@babel/plugin-proposal-decorators"), { legacytrue }],
  [require.resolve("@babel/plugin-transform-runtime"), { corejs}] 

Cool beans.

Do bare in mind that if you use your own webpack config then you are essentially outside of support regarding the PCF CLI - any changes that Microsoft team make you optimising the config you won't benefit from.

@rexkenley  btw - I very much approve of your Ramen themed cases 🍜😋

@rexkenley @ScottDurow  If you would like official support for modifying the webpack config, please make sure to upvote this PowerApps Idea, leave your comments why you want it, and see if you can get others to do the same.

I don't know if 'extending' the webpack scripts is ever going to be a feasible solution?

Perhaps an eject similar to create-react-app? Thoughts @GregHurlmanMSFT 

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