April 2013 - Thought Provoking

Edit : Updated the code as per the suggestions made by Masklinn.

Recently I was working on Issue#1 of my Soulmate Rails gem, which is a very simple and obvious optimization that I should have thought of myself. Thanks to lephyrius though for pointing it out. In my search method I was looping through the search results and calling find on each to get it from db. The fix involved to instead use a single where for all ids so that it translates to a single db call. A simple fix as well as an optimization.

However once I implemented it, I notice my tests were failing. On closer inspection i found they are failing because the models I created for testing using supermodel gem, didn’t have a where method. For a moment I thought WTF, and then I headed on to supermodel and looked through the source and to my surprise, it in fact did not implement a where method. So I took it upon myself to do it.

Here’s the generic code I wrote that could be applied to any array of hashes :

def where(records, options)
  records.select do |r|
    options.all? do |k, v|
      if v.is_a?(Enumerable)
        v.include?(r[k])
      else
        r[k] == v
      end
    end
  end
end

def where(records, options)

records.select do |r|

options.all? do |k, v|

if v.is_a?(Enumerable)

v.include?(r[k])

else

r[k] == v

end

Now you can do

# Eg.1)
where(records, :first_name => 'Dhruva', :last_name => 'Sagar')
# Eg.2)
where(records, :id => [1, 2, 3])

# Eg.1)

where(records, :first_name => 'Dhruva', :last_name => 'Sagar')

# Eg.2)

where(records, :id => [1, 2, 3])

And you will get what you’d expect.

I updated supermodel in my fork to support such a where method and have sent the original author a pull request, hopefully it will get pulled soon.

All my tests pass now! Yay! I have released v0.3.0 of Soulmate Rails. Be sure to check it out.

PS : How about a code review ? Is this optimal or can it be improved further ? I’d like to hear thoughts from others.

Recently I picked up some minor configs for ruby from Tim Pope’s vimrc. Here’s the code :

autocmd FileType ruby
          \ if expand('%') =~# '_test\.rb$' |
          \   compiler rubyunit | setl makeprg=testrb\ \"%:p\" |
          \ elseif expand('%') =~# '_spec\.rb$' |
          \   compiler rspec | setl makeprg=rspec\ \"%:p\" |
          \ else |
          \   compiler ruby | setl makeprg=ruby\ -wc\ \"%:p\" |
          \ endif

autocmd FileType ruby

\ if expand('%') =~# '_test\.rb$' |

\ compiler rubyunit | setl makeprg=testrb\ \"%:p\" |

\ elseif expand('%') =~# '_spec\.rb$' |

\ compiler rspec | setl makeprg=rspec\ \"%:p\" |

\ else |

\ compiler ruby | setl makeprg=ruby\ -wc\ \"%:p\" |

\ endif

What this does is given the filetype is Ruby, it correctly sets up the compiler and makeprg such that it allows you to run your tests via :make! This is pretty neat I must say :), because it correctly loads the quickfix list with the errors and I can actually traverse them in order and fix them. All this without needing any plugin whatsoever :).

Ever since I started using this, I always wanted to mark the lines with errors / warnings with nice signs to highlight lines with errors instantly after I ran :make or :lmake, something similar to what Syntastic does but not just for syntax errors, actual test run errors. As I searched for similar plugins, although I found a bunch of them, I didn’t find them to be very intuitive or simple enough.

Hence I started exploring through vim’s help in an attempt to trying and understanding how I can tap into quickfix & location lists and process them. As it turns out, it’s quite simple and I ended up developing vim-markify overnight.

I’ve made it quite flexible and it works quite well with all quickfix commands – :make, :lmake, :grep, :lgrep, :grepadd, :lgrepadd, :vimgrep, :lvimgrep, :vimgrepadd, :lvimgrepadd, :helpgrep, :lhelpgrep, by tapping into the QuickFixCmdPost autocmd event which triggers right after you run any of the previously mentioned quickfix commands. Although you can choose to disable the autocmd by putting let g:markify_autocmd=0 in your vimrc so that it doesn’t do this automatically and you can trigger :Markify, :MarkifyClear or :MarkifyToggle commands or their corresponding mappings <Leader>mm, <Leader>mc or <Leader>M which can of course be changed. And I was able to achieve all this under 170 sloc :). A lot more things are configurable, I would encourage you to check :h markify.txt within vim or refer to the code at Github.

Screenshot:

M	T	W	T	F	S	S
« Mar				Nov »
1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30

Thought Provoking

iThinks

Monthly Archives: April 2013

ActiveRecord like where for array of hashes in ruby

VIM Markify

Share :

Share :