fix(templatehelper): no styles in Ascii mode

[justenwalker]

If the color profile doesn't support ANSI color codes, then it likely shouldn't support any Style options either. This returns a no-op funcmap from termenv.TemplateFuncs when the color profile is Ascii.

[justenwalker]

If the terminal doesn't support colors, also it doesn't support styles like Bold, Cross-out, etc.

I'm actually not sure this is the case, but I'm not aware of terminals which do support text style options that don't also support colors. And also, from the principle of least surprise -- I'd expect if my color profile is Ascii, I shouldn't be getting any ANSI escape codes in the output. (ie: my output is going to a file, not the terminal)

[justenwalker]

I'm not the biggest fan of doing this kind of comparison and output in tests, but I didn't want to introduce a test-only dependency unless you're ok with it.

A couple I had in mind to make these sorts of tests more readable/maintainable:

• https://github.com/sebdah/goldie for managing golden files (you can run the test with -update to update the files from the code output)
• https://github.com/stretchr/testify has test assertions with useful textual diffs.

[muesli]

I agree, that's probably a sensible suggestion. I haven't looked into goldie yet, but I've used testify before.

[mszostok]

Hi,

First, really cool library 🚀

I wanted to use it and I ran into the same issue today. @muesli are you OK with this change? Do you consider merging it soon?

It is just a helper function, so I just introduce my own. However, it would be to use built-in one ;)

[muesli]

I'm not opposed to the change, it's the right thing to do. I didn't merge it so far, because it was consistent with the actual behavior of termenv's core API. That was always a design issue however and never the intended behavior. Recent API changes (termenv.Output) rectified this situation and as such I'm leaning towards (finally!) merging this PR.