nahurst

# spec/acceptance/support/javascript.rb
RSpec.configure do |config|
  config.use_transactional_fixtures = false

  config.before :each do
    Capybara.current_driver = :selenium if example.metadata[:js]
    if Capybara.current_driver == :rack_test
      DatabaseCleaner.strategy = :transaction
    else
      DatabaseCleaner.strategy = :truncation

nahurst

wget -w 1 -r -k -K -H -N -l 2 http://example.com # pause 1 second between requests, go 2 levels deep

nahurst

# ActiveSupport::TimeWithZone is a rails construct. Always use it for querying and creating.
# DateTime is an old class and is very Ruby specific (not Rails). Don't use it.
# If you put .utc on the end of something other than a DateTime, it's converted to a Time.

                             # <class>                      <to_s>
Time.now                     # Time                         Sun Apr 24 13:00:00 -0400 2011
Time.now.utc                 # Time                         Sun Apr 24 17:00:00 UTC 2011
Time.now.in_time_zone('UTC') # ActiveSupport::TimeWithZone  2011-04-24 17:00:00 UTC
Time.zone.now                # ActiveSupport::TimeWithZone  2011-04-24 17:00:00 UTC
Time.zone.now.utc            # Time                         Sun Apr 24 17:00:00 UTC 2011

nahurst

/**
 * Find a longest common subsenquence.
 *
 * Note: this is not necessarily the only possible longest common subsequence though!
 */
function lcs(listX, listY) {
        return lcsBackTrack(
                lcsLengths(listX, listY),
                listX, listY, 
                listX.length, listY.length);

nahurst

# Browse your local git repository
# If you prefer not to use webrick, you could install lighttpd and then just run git instaweb.
git instaweb --httpd webrick # view at http://localhost:1234

# Browse your local Mercurial repository
hg serve # view at http://localhost:8000

nahurst

# "and" and && are not synonymous in Ruby
# "and" and "or" have a much lower precedence
# "and" and "or" are more like control flow operators than boolean operators

do_this() or raise "Failure"

assign_me = 10 and assign_me / 2 # (assign_me = 10) and assign_me / 2 ... => 5
#vs
assign_me = 10 && assign_me / 2 # assign_me = (10 && assign_me) / 2 ... => undefined

nahurst

v &= v - 1; // clear the least significant bit set
((x ^ y) < 0); // true iff x and y have opposite signs

//more here http://graphics.stanford.edu/~seander/bithacks.html

nahurst

# make a quick backup
cp file{,.bak}

# access files with the same name in different directories
git add app/views/{users,roles}/{index,new}.html