Ruby: How to measure code execution time in an IRB or Rails console

If you are trying to inspect timings in JavaScript, you can use console.time and console.timeEnd which will write to your browser console.

Example:

console.time('lengthy calculation');
lengthyCalculation();
console.timeEnd('len...

At makandra, we've built a few gems over the years. Some of these are quite popular: spreewald (> 1M downloads), active_type (> 1M downloads), and geordi (> 200k downloads)

Developing a Ruby gem is different from developing Rails applications, w...

When you have a hex color code, you can easily convert it into its RGB values using plain Ruby.

>> "#ff8000".match(/^#(..)(..)(..)$/).captures.map(&:hex)
=> [255, 128, 0]

You can use that to implement a simple "hex to CSS rgba value ...

If your irb or rails console keeps randomly crashing and you can't figure out why then you can try to disable multi-line autocomplete.

A check if two date or time ranges A and B overlap needs to cover a lot of cases:

1. A partially overlaps B
2. A surrounds B
3. B surrounds A
4. A occurs entirely after B
5. B occurs entirely after A

This means you actually have to check that:

...

Use Socket.gethostname. So for a machine whose hostname is "happycat", it will look like this:

>> Socket.gethostname
=> "happycat"

That should work right away for your Rails application. For plain Ruby, you first need to do:

requi...

Simplecov is a code coverage tool. This helps you to find out which parts of your application are not tested.

Integrating this in a rails project with rspec, cucumber and parallel_tests is easy.

1. Add i...

When dealing with time zones in Rails, there is one key fact to keep in mind:

Rails has configurable time zones, while
Ruby is always in the server's time zone

Thus, using Ruby's time API will give you wrong results for different...

This cards describes an example with a Github Client on how to keep your Rails application more maintainable by extracting domain independent code from the app/models folder to the lib/ folder. The approach is applicable to arbitrary scenarios...

When you need information about a gem (like version(s) or install path(s)), you can use the gem binary from the command line, or the Gem API inside a ruby process at runtime.

gem binary (in a terminal)

You can get some information abou...