Some rails console tips and tricks

Any rails developer probably uses rails console every day, when testing methods, when debugging, or doing some database modifications, knowing some convenient tips will make you save some time, and on the long run you’ll become more productive with these simple tricks.

Modifying objects safely

Sometimes I need to test a method that modifys some database objects, and at the same time i don’t want to destruct the data, rails console provides you with a neat sandbox, you can delete and modify data as you like, and when you are done all the data is rolled back, this is done using a database transaction. When you run console a second time, you’ll find that all your users are back to normal.

The value of the last expression

Sometimes you write a query and then realize you want that result in a variable, irb keeps the value of the last run expression in a variable called _, here’s an example. Also you can do operations on it directly

Clearing your console

When your console becoems too crowded and you want to start clean, a simple ctrl+L will clear your console.

Reloading models

When you change something in your models and you want to load it in your already running console session you could just run reload! and the model changes will be loaded.
Note that this won’t work on libraries and classes in the lib directory.

Testing view helpers in the console

Sometimes I try to test a view helper, you can easily call those methods using helper prefix