I'm trying to configure npm and gulp to work on a website. When I run gulp, I get these warnings:

% gulp
[14:33:03] Requiring external module babel-register
[14:33:06] Using gulpfile ~/local/mywebsite/wp-content/themes/mywebsitetheme/gulpfile.babel.js
[14:33:06] Starting 'default'...
[14:33:06] Starting 'styles'...
[14:33:06] Starting 'site-js-head'...
[14:33:06] Starting 'site-js-foot'...
[14:33:06] Finished 'default' after 66 ms

assets/js/foot/object-fit-polyfill.js
  line 2  col 75    Confusing use of '!'.
  line 2  col 134   Missing semicolon.
.
.
.
  line 2  col 2673  Missing semicolon.
  line 2  col 2675  Expected an assignment or function call and instead saw an expression.

⚠  25 warnings

[14:33:06] Finished 'site-js-head' after 337 ms
[14:33:09] Finished 'site-js-foot' after 3.13 s
[14:33:09] Finished 'styles' after 3.19 s
%

I've tried npm install objectFitPolyfill to try to get the right code but it doesn't work. Editing this minified .js file seems the wrong way to go. I went to the github of the source for this which is shown in the object-fit-polyfill.js file and tried a copy/paste replacement of the file with the latest, but that doesn't fix it either.

Is there a way to correct things and clear these warnings?