ESM Format modules are not transpiled to ES5.

Describe the bug I am currently encountering the following error when I try import the code into older code base that has ejected create-react-app:

/Users/djohnston/git/project/node_modules/@monaco-editor/react/lib/es/Editor/Editor.js
Module parse failed: Unexpected token (105:6)
You may need an appropriate loader to handle this file type.
|       model: defaultModel,
|       automaticLayout: true,
|       ...options
|     }, overrideServices);
|     saveViewState && editorRef.current.restoreViewState(viewStates.get(autoCreatedModelPath));

The issue appears to be that it doesn’t like the …spread syntax.

To Reproduce

https://github.com/dwjohnston/cra1-monaco

Expected behavior

Of all of the imports this project has been using, this is the first time this error has been encountered - which suggests that every other dependency we use transpiles down to ES5.

Is it reasonable to ask you to transpile the ESM module to ES5?

[dwjohnston]

Alright, here’s the workaround if you are using ejected CRA at react scripts 1.1.5

Add this to your webpack configs:

          {
            test: /\.m?js$/,
            exclude: {
              test: /(node_modules)/, // Exclude libraries in node_modules ...
              not: [

                /@monaco-editor\/react/
              ]
            },
            use: {
              loader: require.resolve('babel-loader'),
              options: {
                babelrc: false, 

                "plugins": [
                  [require.resolve("babel-plugin-transform-object-rest-spread"), { "useBuiltIns": true }]]
                
              }
            }
          },

I do still think that you should accept the PR/transpile the spread operators though.

[dwjohnston]

FYI I’ve posted this question on Stack Overflow re: odd babel behaviour when trying to transpile your package from my end: https://stackoverflow.com/questions/67051317/babel-is-examining-the-package-json-of-a-target-module-for-configuration-when-tr