Route generator should be idempotent

[th1agoalmeida]

This commit demonstrates #22082

[rails-bot]

r? @chancancode

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[th1agoalmeida]

the tests from the first commit point out the extra undesired line from when invoking the command twice in a row.
https://travis-ci.org/rails/rails/jobs/87605507#L3530

[brodock]

To illustrate the problem, check here: hello-gem/hello@a387dd2

This is a very welcome fix and will easy new users workflow.

please, LGTM!

[rafaelfranca]

This is reverting 80838d9 I guess it is fine now that the comments on that file was removed but better to ask @pixeltrix.

[th1agoalmeida]

@rafaelfranca nice catch, and I do agree with @pixeltrix 's POV.
As you said maybe now routes.rb comes blank it will be possible.

[victorlcampos]

+1

[seuros]

could you squash your commits ?
Thank you for your contribution.

[th1agoalmeida]

@seuros squashed

[pixeltrix]

@thejamespinto sorry was on holiday for the first half of this week - can you rebase against master and I will merge. I'm not happy with either option but since Thor's inject_into_file doesn't allow us anymore subtlety and there's no longer the comments in the file then it's fine to flip the other way.

[th1agoalmeida]

@pixeltrix after I read your reasoning I had the same conclusion. thanks for stopping by.

[th1agoalmeida]

@rafaelfranca @seuros thank you guys for helping us here. 💯

[pixeltrix]

@thejamespinto thanks!