Model Testing

Learn about the test database, model testing in Rails, and write tests for your Link model.

Test database

Since your application relies heavily on interactions with a database, you need to have one in your testing environment. Rails provides a dedicated test database allowing you to run your tests in isolation, without having to worry about tampering with your development database.

Loading the database schema

To load the database schema for your test environment you will run:

rake db:schema:load RAILS_ENV=test

This loads the schema from your db/schema.rb file for your test database.

Note: This command will raise an error if there are any pending migrations.

Populating the database

To populate your database, you need to use fixturesfixtures. You will create the following entries in your test/fixtures/links.yml file (this file is auto-generated for your Link model when using scaffolding):


  title: myTitle

linkOne and linkTwo from your fixture file are ActiveRecord instances. This means you can use methods available to the Link class on them.

id1 = links(:linkOne).id
# the id of linkOne will be stored in id1

You will load the fixtures using the following command:

rake db:fixtures:load RAILS_ENV=test

Note: Every Rails app has three environments: development, production, and test. You need to use RAILS_ENV to specify that you are using the test environment.

Now that you have loaded your schema and added a few entries, you can begin writing your tests.

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