Byte Order Mark should be stripped.

[palamccc]

• lets say i am concatenating a.js and b.js
• lets say both have byte order marks in beginning ( some bower packages have BOM on them :-( ).
• gulp-useref concatenates them with byte order mark in between.
• This is majorly because fs.readFileSync don't strip BOM fs.readFileSync(filename, 'utf8') doesn't strip BOM markers nodejs/node-v0.x-archive#1918 , and they say developer should strip it if required.
• so before concatenating BOM should be stripped.

[jonkemp]

One option for you would be to use this module as a workaround.

https://www.npmjs.org/package/strip-bom

It works on streams.

[sindresorhus]

Yup, it's a good practise to strip the BOM. It's really annoying that Node just can't do it though. As the BOM in UTF8 is useless and only added by stupid Windows tools.