Lightning File Upload LWC IE 11 Issue

Question

We are using the lightning-file-upload LWC in a community and have an issue that is only appearing in IE11.

When a user attempts to upload a file in IE11, independent of file extension, they get an error ('Your company doesn't support the following file types:') if we are providing the accept parameter. If we omit the accept attribute, the file uploads without issue.

Is there any IE11 workaround for the lightning-file-upload component?

LWC HTML:

<div if:false={showSpinner}>
    <lightning-file-upload
            label="Upload up to 10 files"
            name="fileUploader"
            accept={acceptedUploadFormats}
            record-id={recordId}
            onuploadfinished={handleUploadFinished}
            multiple>
    </lightning-file-upload>
</div>

JS:

get acceptedUploadFormats() {
    return ['.pdf', '.xls', '.xlsx'];
}

Answer 1

This is because accept is actually comma separated string and not list. By doing below change in JS, it will work:

get acceptedUploadFormats() {
    return '.pdf, .xls, .xlsx';
}

note: I think documentation has some errors - even for other tags, few functionalities are not working as per docs even in chrome browser. You will notice the difference in complex implementations.