
Don't link to line numbers in GitHub - xkarga00
http://andrew.yurisich.com/work/2014/07/16/dont-link-that-line-number/
======
joliss
ProTip: Hit the __y __key on any GitHub page with source code.

It'll instantly expand the URL to its canonical form, e.g.

[https://github.com/sass/libsass/blob/master/parser.cpp#L29-L...](https://github.com/sass/libsass/blob/master/parser.cpp#L29-L36)

to

[https://github.com/sass/libsass/blob/fca1f75a14fe5336c7b1a4b...](https://github.com/sass/libsass/blob/fca1f75a14fe5336c7b1a4b38c69bda7fece714f/parser.cpp#L29-L36)

which stays valid indefinitely (unless the commit is deleted from the repo).

P.S. Hit the __? __key for more keyboard awesomeness. :)

~~~
mapleoin
Yeah, that's what he said in the post.

~~~
Anderkent
Not what he said in the title though. Should be "don't link to non-canonical
urls on github", line numbers are irrelevant.

~~~
lamby
We're meant to read more than the title nowadays?

~~~
kbenson
Like the original comment, my original thought was that it was probably
something to do with people referring to line numbers on HEAD. A less link-
bait title that confirmed this would have allowed me to easily skip this this
article which, for my purposes, was useless.

------
wereHamster
"Don't Link that Line Number!" -> "Don't use unstable references if you need
stable ones"

~~~
DougBTX
Yea, unnecessarily controversial title. The point is that if you want to link
to some code, link to a particular version of that code, not the latest
version of that code. The whole file could be deleted, let alone a change in
line position.

~~~
FooBarWidget
I'm going to play the advocate of the devil here, and say that it's a
_necessary_ controversial title. HN is so crowded these days that an
uncontroversial title would never have gotten enough upvotes within 10 minutes
to get on the front page.

~~~
oddevan
I would also say "necessary" controversial title, but because as a relative
newbie to GitHub I might have made this mistake without thinking about it. Now
I know, whereas before I didn't; and if the title wasn't
engaging/controversial enough for me to click on it, I wouldn't.

------
32bitkid
I had the same realization a while ago, even started working on a
documentation engine built around the idea that I never quite finished:

[https://github.com/32bitkid/zang](https://github.com/32bitkid/zang)

The general concept was a markdown preprocessor that would include references
to commits in git repositories and expand to the referenced content.

Because all the references were bound to a commit, then a) they were stable
(if you used a hash rather than brach name), but more importantly b) you could
determine when the file had changed and the documentation was possibly out of
date.

it would generate a warning/error and one would have to update the
documentation accordingly.

Anyway nice to see other people with the same underlying idea.

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sqs
Or link directly to functions on Sourcegraph, if you are referring to a
function and not just a line range.

Like
[https://sourcegraph.com/code.google.com/p/go/.GoPackage/net/...](https://sourcegraph.com/code.google.com/p/go/.GoPackage/net/http/.def/Get).

(Full disclosure: I'm one of the creators of Sourcegraph.)

~~~
patrickg
I really begin to like sourcegraph, nice job! I don't know how to ask the
question without sounding too negative: any chance it might get faster? I took
about 10 seconds (just a feeling, didn't measure it) to load the page.

~~~
sqs
Not too negative. We love hearing from people who use Sourcegraph. :)

Which page was it, and does it take that long every time you load that page?

We have improved average page load time a lot (it's now 200-500msec), but
we're seeing a lot of variance on pages with a lot of data and when DB load
spikes during backend build imports. So, just know we are working on it, and
let us know about specific things that are really slow. (We track all page
load timings, but we try to prioritize what matters to our users most.)

~~~
patrickg
It was the page you've linked to
([https://sourcegraph.com/code.google.com/p/go/.GoPackage/net/...](https://sourcegraph.com/code.google.com/p/go/.GoPackage/net/http/.def/Get))

just now about 7 seconds (repeatable), on a faster machine it went down to 3
seconds (also repeatable) (all numbers are from me counting in my head, so
this is not exact)

~~~
sqs
Hmm, interesting. I'll follow up with you by email. Thanks for reporting this.

------
potomak
I totally agree. The problem is not links to line numbers, that I found really
useful, the problem is that these links must have a commit context otherwise
they become unreliable.

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simonw
If you use Sublime Text the Githubinator plugin provides shortcuts to create a
permalink to GitHub for the current selection in your editor. I use it all the
time - it's great.

[https://github.com/ehamiter/ST2-GitHubinator](https://github.com/ehamiter/ST2-GitHubinator)

------
bjeanes
> Then, tap the "y" key to jump to the last commit found for that region.

That's not actually what happens. Pressing "y" resolves the current reference
(master, some tag, whatever). It has nothing to do with what you select,
you're just following the pointer that is the current ref.

------
jrochkind1
You can of course link to a line number on a specific commit. You don't need
to avoid line numbers, you just need to link to a specific commit.

The y shortcut is super helpful though -- I was always trying to figure out
how to get the the latest commit hash on my own before, clicking on the latest
commit in history etc., very cumbersome.

This is important enough for linking to sourcecode (I agree), that I kind of
wish github had an actual button for it on screen, instead of having to know
the magic shortcut. But I realize github screen real estate is precious.

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jbert
Is there a reasonable use case for linking to line-numbers on branch/tag on
github? If not, it might be good UX to remove that option. i.e. only honour
such links to immutable urls.

Further, even if you're looking at a mutable reference (like master), the line
number links could/should be to the underlying immutable url (based on the
commit).

If there is a marginal use case for linking to line numbers of mutable refs,
perhaps it should be the non-default case, discoverable by keyboard shortcut
like this...

~~~
warp
Yes, in a team working remotely it is often useful to link to a specific chunk
of code during a (voice or chat) conversation. Typically you're talking about
the _current_ code in a branch, and it is useful for the person clicking the
link to know that we are in fact talking about HEAD and not a specific commit.

This is the equivalent of calling someone to your desk and pointing at the
screen. It is fine if those links stop working a few hours later.

~~~
jbert
I think that also works if the link is actually to the immutable commit to
which the branch is currently pointing?

------
jmileham
This works great unless you're rebasing and the commit hash you reference
falls out of use. In PR comments that I expect to rebase again before release
but for which I don't expect changes earlier in the file I'm referencing, I
often live on the edge and link to the mutable diff. In the context of PR
comments, you can edit them after the fact, so neither choice is necessarily
game over - you can fix the line number or the commit hash you point to after
the fact.

~~~
sergiosgc
You already know the answer to that problem: «Do not rebase commits that you
have pushed to a public repository.» - - [[http://git-scm.com/book/en/Git-
Branching-Rebasing](http://git-scm.com/book/en/Git-Branching-Rebasing)]

~~~
jmileham
Trite one-liners aside, I think you'll find in practice that some good teams
rebase commits on feature branches all the time in order to keep the commit
history readable. The implicit contract in that case is that nobody else
considers that branch to be usable until it's merged.

It all comes down to the definition of publicity. If your team considers a
feature branch to be privately owned by the requestor except for the purposes
of code review, it works great.

~~~
sergiosgc
I do not mind feature branch rebasing, _when_ it does not violate the
publicity rule (let's call it that). After the history is public, rewriting
history is such a dangerous endeavor as to be completely inadvisable. More so,
if one is actually looking at the end goal: a linear repository history. I
can't even understand the need for a (fake) linear repository history.

~~~
jrochkind1
I have come to understand the need.

If a feature branch is under development for a year, and then merged in....
you wind up with commits in master that only appeared today, but are dated
(and appear in the commit history timeline) up to a year ago. It's actually a
different kind of 'rewriting history', really.

This can be very confusing when trying to figure out what happened. And even
worse when trying to figure out where a bug was introduced (via git bisect or
manually).

Still, I, like you, try to avoid rebase history rewrites whenever possible,
because they can lead to such messes. But I've come to understand why people
want them, it's not just "aesthetically pleasing commit history", which sounds
kind of inane I agree.

Then "only when it's not public" rule effectively means "never do it" for most
people's development practices. Anything that takes longer than an hour or so
for me to do is going to be in a public repo, for the 'backup' nature of
making sure i don't lose it while in progress if nothing else. Anything that
more than one person collaborates on (or you want code review suggestions on)
obviously is going to be in a public repo. It's pretty rare feature branch
work I do that never makes it into a public repo (before it's committed to
master).

------
albertzeyer
I often wished that I could link to function names or so instead.

~~~
pjtr
In Trac you can link to #/searchterm.

------
nathell
I've always linked to line numbers under specific commits or tags. Didn't know
about the 'y' shortcut though, very helpful.

------
adamwong246
That's easy to fix- link to a line in a specific commit. Assuming you never
clobber the history, that link should remain constant.

------
ttty
Anyone with minimal knowledge of github would know that the references can
changes...

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ad_hominem
This has nothing to do with line numbers whatsoever, it's about constructing
links using whatever commit the branch is currently on rather than linking to
the branch. A regular link to a file using a branch reference could just as
easily disappear completely as the branch reference moves.

~~~
trebor
Please don't mention that you flagged the OP. That's against the guidelines:
_If you flag something, please don 't also comment that you did._

------
bttf
Short but informative

------
fjcaetano
Someone just discovered space-time

------
WorldWideWayne
Why change the title to "Don't link to line numbers in GitHub", when that's
not what the article is saying at all?

~~~
danneu
The original title is "Don't Link that Line Number" which also isn't what the
article is saying, so the HN re-title is an improvement.

An accurate title would look more like "Use commit-specific links when linking
to line numbers on Github".

~~~
WorldWideWayne
The original title (as written in the article), is actually "Don't Link That
Line Number!" Even without the exclamation though, I think that clueful
readers would know that this choice of title is a stylistic one.

Title choice _is_ largely a matter of style. So, I guess I'm wondering why any
of them need to be changed?

Furthermore, it seems to be completely arbitrary. The techcrunch article
titled "#Love: Virtually No Sex" if made accurate would have been "People may
be losing interest in sex". The "Simpler and faster GC for Go" would have been
"Proposal for Simpler and faster GC for Go". Etc.

~~~
danneu
I agree. I misinterpreted your initial comment.

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kernelcurry
Why would you assume that a link is good for more than 1 day ?

~~~
simonw
[http://www.w3.org/Provider/Style/URI.html](http://www.w3.org/Provider/Style/URI.html)

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andyhmltn
Is it not possible to link to line numbers in that commit? I know you can link
to specific files in the commits

~~~
cpach
It is possible, which the author points out in his article :)

~~~
andyhmltn
Woops! My bad

