Check which packages and versions apt would install before making changes. --dry-run simulates upgrades without touching the system.

Ruby 1.8.6 is incompatible with newer RubyGems releases; RubyGems 1.4.2 remains the last version that installs successfully.

One of the thornier problems in our workflow is knowing when assets are delivered from the designer and keeping them in sync with our application as they change. We used to use e-mail, Skype or sticky notes. The trouble is that the designer's file naming and directory structure were never quite the same as the application's /public/images directory, so direct comparisons were impossible and we ended with a lot bookkeeping to make sure that we didn't lose any changes. Our solution is to clone the project's git repository into a folder inside ...

iPhone and iPad browsers do not allow JavaScript to open the on-screen keyboard programmatically. The keyboard appears only after a user gesture in an editable field.

RMagick gem installation can fail when ImageMagick development files or config tools are missing. Installing the matching libmagickcore-dev and libmagickwand-dev packages usually resolves it.

Opera’s User mode can toggle HTML element outlines quickly, making layout debugging easier when actual element dimensions and float behavior matter.

Opera 11 hides URL parameters and the protocol in the address field until focus, making copied links incomplete. A browsing preference restores the full web address display.

It is common in Rails 3.0 applications that you want to provide default views for a group of controllers. Let’s say you have a bunch of controllers inside the Admin namespace and you would like each action to fallback to a default template. So if you are rendering the index action for Admin::PostsController and “app/views/admin/posts/index.html.*” is not available, it should then render “app/views/admin/defaults/index.html”.

Since Rails 3.0, we have a new abstraction called resolvers that holds the logic to find a template.

Manually verify outbound e-mail delivery from a machine with mail from the shell, either empty or with a typed message body.

becomes casts an ActiveRecord record to a different STI class so Rails can treat it as another type, while both instances share the same attributes.

Artifice allows you to replace the Net::HTTP subsystem of Ruby with an equivalent that routes all requests to a Rack application.

You can use Sinatra, raw Rack, or even Rails as your application, allowing you to build up an equivalent to the remote service you are mocking out using familiar and convenient tools to route requests and build up responses.

mitmproxy is an SSL-capable, intercepting HTTP proxy. It provides a console interface that allows traffic flows to be inspected and edited on the fly.

Rails 2 and some Rails 3.x versions let chained scopes overwrite hash conditions on the same attribute, creating authorization leaks. chain_safely avoids that overwrite.

Unexplained whitespace at the top of a page can come from a BOM in one of the rendered views; saving the file without a BOM removes it.

Imperative and declarative user-story scenarios suit different situations; declarative phrasing offers advantages in RSpec Story Runner and Cucumber testing.

Google’s Font Directory and API for web fonts could have a transformative effect on how we read the web. The only problem is, Google has made it very difficult to download all of the actual font files.

Web designers must be free to experiment with these new fonts, to sketch, comp and get to know these typefaces in browser and non-browser applications. This is why I’m providing this archive.

Use hash_including in RSpec to verify a hash or method call contains only the expected key-value pairs without matching the full structure.

Different styling for Internet Explorer can be generated with Sass variables and conditional imports without relying on CSS hacks.

ActionMailer can send empty messages when recipient arrays are generated dynamically; overriding deliver! prevents delivery when to, cc, and bcc are all blank.

tetex is no longer supported on Ubuntu 10.10; texlive provides a supported LaTeX installation via apt-get.

Rails startup can fail with a NameError when version_requirements is missing on Rails::GemDependency; a small environment.rb patch restores compatibility with newer RubyGems.

Capybara now includes an RSpec acceptance-testing DSL, replacing much of Steak’s earlier role and making end-to-end testing in RSpec more seamless.