[Feature Request] Add ability to trim values for the header row

[ragingdave]

During usage, we've come across multiple times where the header row of a csv has errant leading or trailing whitespace. This causes processing issues as then the column might be recognized as test instead of test. I've reviewed old issues and PRs for box/spout and it seems they have made that decision to not trim "cell" values back in 2016, but headers have a bit of a different handling of them and adding an option to trimHeaders to the configuration of the reader might be something useful.

I can certainly work on creating this feature if it were to be a welcome addition as we are looking at options to resolve this human error at the code level.

trimHeaders could basically be a pass-through to trim and allow customization of the characters to remove
so for the most part it would look like this (all untested, just off the cuff here):

public function trimHeaders($characters = null)
{
    $this->trimHeaders = true;
    $this->trimHeaderCharacters = $characters;
}

and in usage, when the headers are set from $firstRow->toArray(), we would just simply map over them and apply trim optionally if enabled.

$this->headers = $firstRow->toArray();

if ($this->trimHeaders) {
    array_walk($this->headers, fn ($header) => trim($header, $this->trimHeaderCharacters));
}

Let me know if this would be something that would be worthwhile adding.

[freekmurze]

I'd accept a PR with updated docs and tests that improve this.

[ragingdave]

I'll try and get something together some time this week.