Set Rails environment to test before invoking extension:test_app task

[gsmendoza]

This fixes the following error when running bundle exec rake in SolidusPaypalCommercePlatform:

An error occurred in a `before(:suite)` hook.
Failure/Error: //= link spree/backend/all.js

Sprockets::FileNotFound:
  couldn't find file 'spree/backend/all.js'
  Checked in these paths:
    /home/gsmendoza/repos/solidusio-contrib/solidus_paypal_commerce_platform/spec/dummy/app/assets/config
    /home/gsmendoza/repos/solidusio-contrib/solidus_paypal_commerce_platform/spec/dummy/app/assets/images
    /home/gsmendoza/repos/solidusio-contrib/solidus_paypal_commerce_platform/spec/dummy/app/assets/stylesheets
    /home/gsmendoza/repos/solidusio-contrib/solidus_paypal_commerce_platform/app/assets/javascripts
    /home/gsmendoza/repos/solidusio-contrib/solidus_paypal_commerce_platform/app/assets/stylesheets

Cause

extension:specs, the default rake task of SolidusPaypalCommercePlatform, executes the rake tasks and Ruby methods below in the given order:

• The extension namespace defined in SolidusDevSupport::RakeTasks#install_test_app_task. This namespace invokes the extension:test_app task (https://github.com/solidusio/solidus_dev_support/blob/e5fec9c039607ab9e97c3f821cc49f9bbec08796/lib/solidus_dev_support/rake_tasks.rb#L47).

• The Solidus extension:test_app task (https://github.com/solidusio/solidus/blob/07c88ddd1603699939ac0343965fa88dc2e1851a/core/lib/spree/testing_support/extension_rake.rb#L7)

• The common:test_app rake task in CommonRakeTasks#initialize (https://github.com/solidusio/solidus/blob/07c88ddd1603699939ac0343965fa88dc2e1851a/core/lib/spree/testing_support/common_rake.rb#L14)

• Solidus::InstallGenerator#setup_assets (https://github.com/solidusio/solidus/blob/07c88ddd1603699939ac0343965fa88dc2e1851a/core/lib/generators/solidus/install/install_generator.rb#L81)

The setup_assets method would only install the all.* frontend and backend assets if either

• Spree::Frontend and Spree::Backend are loaded, or
• The Rails environment is test.

Currently, when we run bundle exec rake in SolidusPaypalCommercePlatform, neither condition is met:

• Spree::Frontend and Spree::Backend are NOT loaded.
• The Rails environment is development.

Trigger

This bug surfaced after we applied https://github.com/solidusio/solidus/pull/4251 (Fix: solidus:install adds the frontend assets even if the repo does not have solidus_frontend).

Solution

Considering that the extension:test_app rake task generates the spec/dummy directory, we can assume that it is expected to run under test environment.

Testing

• gsmendoza/eng-340-fix-soliduspaypalcommerceplatform-bundle--debug tests the fix against SolidusPaypalCommercePlatform. Here's the output of its bundle exec rake stripped off deprecation warnings and other noise: 2022-06-08-solidus-paypal-commerce-platform-output.txt.

Checklist

• [x] I have structured the commits for clarity and conciseness.
• [x] I have added relevant automated tests for this change.

[mergify[bot]]

It looks like this PR is missing a label to determine the type of change it introduces. The maintainer should add one of the following labels:

• bug for bugfixes.
• enhancement for new features and improvements.
• documentation for documentation changes.
• security for security patches.
• removed for feature removals.
• infrastructure for internal changes that should not go in the changelog.

Additionally, the maintainer may also want to add one of the following:

• breaking for breaking changes.
• deprecated for feature deprecations.

Once the correct labels have been set, simply remove the needs changelog label label from this PR so I can merge it.

[gsmendoza]

Closing this for now. I have just noticed that common:test_app already sets up RAILS_ENV to test, but it's not being picked up by Solidus::InstallGenerator. Will investigate.