Ruby Cheatsheet

Debugging ruby code with bundler open

bundler open GEM-NAME

This will open up the source code of the gem installed using the editor set by the environment variables EDITOR or BUNDLER_EDITOR

You can set breakpoints, change the source code, grep through it with your editor.

Once debugging is finished run bundler pristine to reset any changes

• Reference: Search and debug ruby code with bundler open

Placeholder String Trick

Ruby has a trick for creating placeholders within a string and then populating the placeholders’ positions with an array of values.

VERSE = "On the %s day of Christmas my true love gave to me: %s."

VERSE % ["first", "a Partridge in a pair tree"]

The % inserts the array of values sequentially into the %s portions of the text