Rails - Sep 2005 - Automagically creating fixtures from current database contents?

I''m accumulating numerous test scripts, and finding that I often want
to
work with more prepopulated data.

Rather than create fixtures by hand, I''d rather be able to take the 
current state of the database and serialize it to a set of fixture files 
that I can reload at a later date for more testing.

I''ve been hacking together assorted one-offs that dump to the browser, 
as YAML text, the current set of values for any specific object, but I 
would rather just have a single
''save_current_database_as_fixtures'' task.

Before I reinvent the wheel, does such a beast exist?

Thanks,


James Britt

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On 9/18/05, James Britt
<james.britt-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> I''m accumulating numerous test scripts, and finding that I often
want to
> work with more prepopulated data.
> 
> Rather than create fixtures by hand, I''d rather be able to take
the
> current state of the database and serialize it to a set of fixture files
> that I can reload at a later date for more testing.
> 
> I''ve been hacking together assorted one-offs that dump to the
browser,
> as YAML text, the current set of values for any specific object, but I
> would rather just have a single
''save_current_database_as_fixtures'' task.
> 
> Before I reinvent the wheel, does such a beast exist?
I''m currently doing the opposite.  I populate the development database
from my test fixtures.

Here''s the rake task for what I''m doing:
desc  "Load fixtures data into the development database"
task :load_fixtures_data_to_development do
  require ''active_record/fixtures''
  RAILS_ENV = ''development''
  require File.dirname(__FILE__) + ''/config/environment''
  ActiveRecord::Base.establish_connection()
  Fixtures.create_fixtures("test/fixtures", 
    %w(amenities amenities_houses communities communities_contractors
       contacts contents contractors houses images users))
end

(there''s probably a better way to specify what fixtures should be
loaded though)

But it works well for me.  I also have a migration that sets up the
tables in the database.  So, when I want to start up a new development
env, I just check out the svn, create the databases, then run ''rake
migrate'' and ''rake
load_fixtures_data_to_development''.

James Britt wrote:
> I''ve been hacking together assorted one-offs that dump to the
browser,
> as YAML text, the current set of values for any specific object, but I 
> would rather just have a single
''save_current_database_as_fixtures'' task.
> 
> Before I reinvent the wheel, does such a beast exist?
def yaml_for_class(cls)
   records = cls.find(:all)
   underscored = cls.name.underscore
   records.inject({}) do |hash, record|
     key = "#{underscored}_#{hash.length + 1}"
     hash[key] = record.attributes
     hash
   end.to_yaml
end

It would be nice if the order of the fields could be specified, but 
whatever.

Joe Van Dyk wrote:
> On 9/18/05, James Britt
<james.britt-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 
>>I''m accumulating numerous test scripts, and finding that I
often want to
>>work with more prepopulated data.
>>
>>Rather than create fixtures by hand, I''d rather be able to take
the
>>current state of the database and serialize it to a set of fixture files
>>that I can reload at a later date for more testing.
>>
>>I''ve been hacking together assorted one-offs that dump to the
browser,
>>as YAML text, the current set of values for any specific object, but I
>>would rather just have a single
''save_current_database_as_fixtures'' task.
>>
>>Before I reinvent the wheel, does such a beast exist?
> 
> 
> I''m currently doing the opposite.  I populate the development
database
> from my test fixtures.
> 

Which is what I do, too, and why I want to be able to grab a snapshot of 
the database at any time and save it off as a fixture set. It will allow 
me to create repeatable test scenarios without my having to hand-edit 
the fixture YAML (an error-prone process).

James

-- 

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Nicholas Seckar wrote:
> James Britt wrote:
> 
>> I''ve been hacking together assorted one-offs that dump to the
browser,
>> as YAML text, the current set of values for any specific object, but I 
>> would rather just have a single
''save_current_database_as_fixtures'' task.
>>
>> Before I reinvent the wheel, does such a beast exist?
> 
> 
> def yaml_for_class(cls)
>   records = cls.find(:all)
>   underscored = cls.name.underscore
>   records.inject({}) do |hash, record|
>     key = "#{underscored}_#{hash.length + 1}"
>     hash[key] = record.attributes
>     hash
>   end.to_yaml
> end
> 
> It would be nice if the order of the fields could be specified, but 
> whatever.
Order is probably not a big deal.

I was thinking of writing a module so that I could mix-in a class method 
for all my models, then write a master script to loop over the tables in 
the database and invoke some to_fixture method on each one.

Thanks,


James


-- 

http://www.ruby-doc.org - The Ruby Documentation Site
http://www.rubyxml.com  - News, Articles, and Listings for Ruby & XML
http://www.rubystuff.com - The Ruby Store for Ruby Stuff
http://www.jamesbritt.com  - Playing with Better Toys

Nicholas Seckar wrote:
> James Britt wrote:
> 
>> I''ve been hacking together assorted one-offs that dump to the
browser,
>> as YAML text, the current set of values for any specific object, but I 
>> would rather just have a single
''save_current_database_as_fixtures'' task.
>>
>> Before I reinvent the wheel, does such a beast exist?
> 
> 
> def yaml_for_class(cls)
>   records = cls.find(:all)
>   underscored = cls.name.underscore
>   records.inject({}) do |hash, record|
>     key = "#{underscored}_#{hash.length + 1}"
>     hash[key] = record.attributes
>     hash
>   end.to_yaml
> end
> 
> It would be nice if the order of the fields could be specified, but 
> whatever.
Thanks for the code example.  It''s a bit cleaner than what I was doing.

I''ve taken a stab at a Rake task for creating fixture files from a 
database, which can be seen at:

http://www.jamesbritt.com/index.rb/Development@Rails_Fixtures_from_Database_Contents.txt

James Britt

-- 

http://www.ruby-doc.org - The Ruby Documentation Site
http://www.rubyxml.com  - News, Articles, and Listings for Ruby & XML
http://www.rubystuff.com - The Ruby Store for Ruby Stuff
http://www.jamesbritt.com  - Playing with Better Toys