NPE while saving an unmodified file

[innerjoin]

If you save a file which has not been modified, the webpack build will be triggered and the plug-in will fail with an exception
Where: index.js:41 @ const toReplace = source.match(replacementExpr)[1];
Error: TypeError: Cannot read property '1' of null
AND
Where: index.js:40 @ const depExtractions = source.match(dependencyExtractorExpr);
Error: NPE