Auto-link to GitHub issue in Markdown

[mnapoli]

GitHub will automatically create a link to an issue in Markdown with text like this:

Implemented in #123.

Couscous could support the same behavior and turn #123 into [#123](https://github.com/CouscousPHP/Couscous/issues/123).

It would only work if the GitHub project is configured in couscous.yml, e.g.:

github:
    user: symfony
    repo: console

(same options that what's used in the default template)

[Zolli]

Is this necessary to only works if github integration is enabled?
What if we allow to define a new configuration value:

(I use Phabricator link structure in this example)

issueLink: http://management.company.com/T#ISSUE_ID#

In your example the link for ths issue will be the following: http://management.company.com/T123
Of curse this may be a better solution because not break compatibility in the feature, and, if the user migrates from one issue tracking system to an other the links is easily replaceable.

[cyberbit]

+1 @Zolli's idea. I'm currently trying to implement Couscous into a new release documentation system, but we don't use GitHub at my organization. Having customizable issue links when deploying to something other than GitHub would be fantastic. If I find time, I might be able to submit the pull request to do both GitHub and custom integration, as it's important to me.

[mnapoli]

Sounds fair, and doable I guess. There has been a new release hours ago of the commonmark parser, and with the new AST and extension system it seems way easier than before to implement that. For example there is a "twitter auto-linker" plugin: https://github.com/thephpleague/commonmark-extras/blob/master/src/TwitterHandleAutolink/TwitterHandleParser.php

We still need Markdown Extra support however before being able to switch to this Markdown parser :/ (see #134).

[Zolli]

Currently, i try to create a Step that replaces issue numbers but i run into a problem with this :)

• is already occupied by header definition in markdown

There is 2 possible soluton:

1. Use a custom prefix
   ISSUE-#NUMBER_HERE be nice.
2. Provide user a way to customize issue matching regex.
   So, we provide a default scheme (like in previous example), and if the user provides a custom one the matcher use this.

This raises some inconsistency across projects, so I do not recommend this.

[mnapoli]

@Zolli I haven't looked into the details of the parser but isn't that possible to register # only when it's not the first character of the line?

[Zolli]

@mnapoli i think of that, but what if the user want to place the issue number to the beginning of the line? That is a big limitation.

Example:

...
### Limitations

#1212 is the main limitation...
#2121 also...

[mnapoli]

Actually I just realized that #123 is not interpreted as a title so it's perfectly valid to turn it into an issue link. Try it out at http://spec.commonmark.org/dingus/