ReferenceError: File is not defined at isObject v1.4.0

[davidb-e4s]

Prerequisites

• [ x] I have read the documentation;
• [ x] In the case of a bug report, I understand that providing a SSCCE example is tremendously useful to the maintainers.
• Ideally, I'm providing a sample JSFiddle or a shared playground link demonstrating the issue.

Description

Since 1.4.0 I'm now getting this error when trying to create a form

ReferenceError: File is not defined at isObject (/srv/node_modules/react-jsonschema-form/lib/utils.js:325:24) at getDefaultFormState (/srv/node_modules/react-jsonschema-form/lib/utils.js:288:8) at Form.getStateFromProps (/srv/node_modules/react-jsonschema-form/lib/components/Form.js:157:53) at new Form (/srv/node_modules/react-jsonschema-form/lib/components/Form.js:129:25)

I believe this is related the isObject file changes in 1.4.0

1.3.0 works fine

My browser is Chrome 73.0.3683.86 on Mac OS Mojave 10.14

Steps to Reproduce

1. Update lib to 1.4.0
2. Create a Form in react with no formData specified or an empty object
3. The form fails to render with the above error
4. Note I only observed this in a Next.js app v ^7.0.3

Expected behavior

The form to render correctly. Switching back to 1.3.0 makes the form work as expected.

Actual behavior

The form failed to error and the console showed the aforementioned error

Version

1.4.0

[paintedbicycle]

I'm too am getting this everywhere in my app after updating to 1.40

[epicfaace]

Hmm, so this seems to be happening in a node js environment, not the browser, is that right?

[paintedbicycle]

You might be correct. I first noticed the Errors in my cloud function console (which runs node as the environment). So it's happening there.

I finally saw it in the browser and had to downgrade. However the browser error might have been caused by a crash in the node server powering the site (i.e. it might have been a server crash screen).

[davidb-e4s]

I've not seen it in my pure react app so it could be when running on node. Using NodeJs10. Happens on both my local machine and when deployed to Google App Engine.