Template file extension

[ilkka]

This PR changes template rendering such that only template files that end in ".tmpl" get run through the template engine. Other files in the templates directory get rendered as-is.

Not sure if it would be worth it to also rename the "templates" directory to something else since it will now also contain non-templated things?

Closes #39.

[majori]

I was wondering the case where for example env.local.tmpl is wanted to be copied to the repo. Should it be then be env.local.tmpl.tmpl in the recipe so the wanted prefix is not removed in project context?

[ilkka]

Oof :D that's a good point, and yeah that should be a viable workaround. It's not very nice though, I wonder if some other sort of "filename escaping" would be better, like ._tmpl -> .tmpl or whatever

[majori]

Not sure if it would be worth it to also rename the "templates" directory to something else

Yeah, I agree that it is then misleading if all of the files are not rendered

[ilkka]

I'm thinking is skipping non-.tmpl files feature of a engine, or should it be same for all engines? So when calling recipe.engine.Render() method, should only the templates be passed as a parameter, or all files

Should there be a "NOP-engine" that gets all the non-template files?

[majori]

Should there be a "NOP-engine" that gets all the non-template files?

Or is it just something what happens before recipe.engine.Render() is called?

[ilkka]

I found another way in which this is a problematic design. This is demonstrated by TestRecipeRenderChecksums: it uses TestRenderEngine which doesn't know anything about this name change, and therefore the test will start failing if the template name gets the .tmpl file extension. So the file extension is kind of part of the render engine API contract now, but in a really implicit way.

That makes me think if the big picture here isn't "skip templating", but actually that recipes should be able to have many different types of files all processed with different engines -- one of which is gotpl and uses the .tmpl filename extension.

[majori]

should be able to have many different types of files all processed with different engines

Interesting idea that there could be multiple engines in use at the same time

[ilkka]

Alright, I exploded everything and did another version :D In this version the determination of whether to use templating is not is not with the engine but with the recipe. This circumvents the problem with TestRenderEngine that I mentioned above. It's also opt-in because if there is no template extension defined on the recipe, everything gets rendered like before.

[ilkka]

Eh, here I was rebasing and force pushing and forgot that we always squash anyway 🤦🏻