304600 - Need a test in the test suite to check for dependency loops

Status: RESOLVED FIXED

(Bugzilla :: Testing Suite, enhancement)

Description

[Max Kanat-Alexander]

We should be able to adapt justdave's use2dot script (from bug 303413) and our
dependency-loop-checking code for process_bug into a test that determines
whether or not our libraries contain dependency loops.

Comment 1

[Paul]

This bug is speaking about code dependencies not "bug xxx depends on" and "bug yyy blocks" type dependencies... right?

Comment 2

[Frédéric Buclin]

(In reply to comment #1)
> This bug is speaking about code dependencies not "bug xxx depends on" and "bug
> yyy blocks" type dependencies... right?

Right! If Foo.pm uses Bar.pm, then Bar.pm should not use Foo.pm.

Comment 3

[Dave Miller [:justdave]]

Attachment: use2dot.pl v2

This version of use2dot.pl improves on the previous version by detecting and reporting dependencyloops that are more than one level deep.

example output:

[dave@g4book bugzilla]$ perl ../../misc/use2dot.pl > ~/bugzilla.dot
Dependency on Bugzilla::Attachment from Bugzilla::Flag causes loop.
Dependency on Bugzilla::BugMail from Bugzilla::Flag causes loop.
Dependency on Bugzilla::Product from Bugzilla::Classification causes loop.
Dependency on Bugzilla::User from Bugzilla::Component causes loop.
Dependency on Bugzilla::Bug from Bugzilla::BugMail causes loop.
Dependency on Bugzilla::Flag from Bugzilla::Attachment causes loop.
Dependency on Bugzilla::Component from Bugzilla::Product causes loop.
Dependency on Bugzilla::Product from Bugzilla::User causes loop.
Dependency on Bugzilla::Classification from Bugzilla::User causes loop.
Dependency on Bugzilla::Attachment from Bugzilla::Bug causes loop.
Dependency on Bugzilla::Flag from Bugzilla::Bug causes loop.

You can then use the produced ~/bugzilla.dot file to generate a pretty graph with red lines on the loops like so:

dot -Tpng ~/bugzilla.dot >~/Desktop/bugzilladeps.png

Comment 4

[Frédéric Buclin]

Attachment: 010dependencies.t

This is based on use2dot.pl justdave wrote.

Comment 5

[Dave Miller [:justdave]]

Comment on attachment 225930 [details]
010dependencies.t

Looks like it works.  Seems to be flagging all the right things.  Tree's gonna go red when this is checked in though.

Comment 6

[Frédéric Buclin]

(In reply to comment #5)
> Looks like it works.  Seems to be flagging all the right things.  Tree's gonna
> go red when this is checked in though.

One way to prevent to lit the tree is to ignore |require Bugzilla::Foo| which are inside routines. This means writing (?:use|^require) instead of (?:use|require). I checked, there is no dependency loops detected this way. From what mkanat said on IRC, having Perl modules requiring each others is not a problem, e.g. for mod_perl.

I could commit this patch with the change above (on checkin).

Comment 7

[Max Kanat-Alexander]

(In reply to comment #6)
> I could commit this patch with the change above (on checkin).

  That sounds right to me.

Comment 8

[Frédéric Buclin]

Checking in t/010dependencies.t;
/cvsroot/mozilla/webtools/bugzilla/t/010dependencies.t,v  <--  010dependencies.t
initial revision: 1.1
done

Comment 9

[Max Kanat-Alexander]

Added to the release notes on bug 349423.