Add a envOrDefault helper

[nicolasbernard]

Feature Request

For a new project we use a bench of {{ if env "TIMEOUT_CONNECT" }}{{ env "TIMEOUT_CONNECT" }}{{ else }}5s{{ end }} which is a bit verbose and redundant.

It would be very conveniant to use a syntax like {{envOrDefault "TIMEOUT_CONNECT" "5s"}}

It should be trivial to implement, I can make a pull request if you are ok with it.

[sethvargo]

Hi @nikkau

You should be able to use the built-in or operator like this:

{{ or (env "TIMEOUT_CONNECT") "5s" }} 

Does that work?

[nicolasbernard]

Hi,

It works, but {{ env }} rely on os.Getenv which always return a string, an empty one when the var doesn't exists, it works only because {{ or }} consider "" falsy which is not the case in all language, so not intuitive imho.

{{ envOrDefault }} could use os.LookupEnv to return default value only when the var doesn't exists in environment.

I don't know if someone need this stricter behavior (today I don't, the "or pattern" does the trick).

I also think explicit helper have value for the sake of explicitness, for coherence with the existence of keyOrDefault

[sethvargo]

Hi @nikkau

Thank you for your response. I am going to close this out until someone has a stricter use case. Thanks!

[dfredell]

Hello,

I was searching high and low for this answer. {{ or (env "TIMEOUT_CONNECT") "5s" }} does exactly what I want it to do. It was just hard to find.

I would like to make it easier for the next person to find. Can I make a PR to update the docs and add this example?

The another option would be to make the envOrDefault function like @nikkau suggested. It would be very intuitive and easy to read. {{envOrDefault "TIMEOUT_CONNECT" "5s"}}

[slackpad]

Can I make a PR to update the docs and add this example?

Sure @dfredell we'd welcome that!

[jtrinklein]

I also had a very hard time finding the solution to this. I'd like to submit a PR to add the envOrDefault helper.

[eikenb]

@jtrinklein, if you'd like to submit a PR with this feature I'll happily review it for possible inclusion. Please remember tests. Thanks.