Bundle exec for isolated execution in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to run a Ruby script with Bundler ensuring isolated gem execution.

Ruby

system('[1] ruby my_script.rb')

Drag options to blanks, or click blank then click option'

Arake

Bruby

Cgem install

Dbundle exec

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'ruby' alone runs the script but ignores Bundler gem isolation.

Using 'gem install' is for installing gems, not running scripts.

Using 'rake' is for running tasks, not general Ruby scripts.

Using bundle exec runs the Ruby script with gems isolated to the bundle environment.

2fill in blank

medium

Complete the command to install gems and then run a script isolated with Bundler.

Ruby

bundle install && [1] ruby app.rb

Drag options to blanks, or click blank then click option'

Abundle exec

Bruby

Cgem install

Drake

Attempts:

3 left

💡 Hint

Common Mistakes

Running 'ruby' alone ignores Bundler isolation.

Using 'gem install' is for installing gems, not running scripts.

Using 'rake' is unrelated to running arbitrary Ruby scripts.

After installing gems, bundle exec runs the script using the installed gems isolated by Bundler.

3fill in blank

hard

Fix the error by completing the command to run a Rake task with Bundler isolation.

Ruby

[1] rake db:migrate

Drag options to blanks, or click blank then click option'

Aruby

Bgem install

Cbundle exec

Drake

Attempts:

3 left

💡 Hint

Common Mistakes

Running 'rake' alone may use system gems, causing version conflicts.

Using 'ruby' alone does not run rake tasks.

Using 'gem install' is for installing gems, not running tasks.

Using bundle exec before rake ensures the task runs with the correct gem versions.

4fill in blank

hard

Fill both blanks to create a command that installs gems and runs a Ruby script isolated by Bundler.

Ruby

[1] install && [2] ruby script.rb

Drag options to blanks, or click blank then click option'

Abundle

Bbundle exec

Cgem

Drake

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'gem install' instead of 'bundle install' for gem installation.

Not using 'bundle exec' to run the script causes gem version conflicts.

The first blank is bundle to install gems, and the second is bundle exec to run the script with gem isolation.

5fill in blank

hard

Fill all three blanks to create a command that installs gems, runs a Rake task, and then runs a Ruby script all isolated by Bundler.

Ruby

[1] install && [2] rake db:seed && [3] ruby app.rb

Drag options to blanks, or click blank then click option'

Abundle

Bbundle exec

Crake

Druby

Attempts:

3 left

💡 Hint

Common Mistakes

Running rake or ruby commands without 'bundle exec' causes gem conflicts.

Using 'rake' or 'ruby' alone without 'bundle exec' ignores the Gemfile.lock.

Use bundle to install gems, then bundle exec to run both the rake task and the Ruby script with gem isolation.

Practice

1.

What is the main purpose of using bundle exec in a Ruby project?

easy

A. To create a new Ruby project with default settings

B. To update all gems to their latest versions globally

C. To uninstall unused gems from the system

D. To run commands using only the gems specified in the project's Gemfile

Solution

1. Step 1: Understand the role of bundle exec

   bundle exec runs commands using the gems listed in the project's Gemfile, isolating from other system gems.

2. Step 2: Compare options

   Options B, C, and D describe different gem or project management tasks unrelated to isolated execution.

3. Final Answer:

   To run commands using only the gems specified in the project's Gemfile -> Option D

4. Quick Check:

   bundle exec isolates gems = A [OK]

Hint: Remember: bundle exec uses project gems only, avoiding conflicts [OK]

Common Mistakes:

• Thinking bundle exec updates gems
• Confusing bundle exec with gem uninstall
• Assuming bundle exec creates projects

2.

Which of the following is the correct syntax to run a Ruby script app.rb using bundle exec?

easy

A. bundle exec ruby app.rb

B. ruby bundle exec app.rb

C. bundle ruby exec app.rb

D. exec bundle ruby app.rb

Solution

1. Step 1: Recall correct command order

   The correct syntax places bundle exec before the command to run, here ruby app.rb.

2. Step 2: Validate options

   Only bundle exec ruby app.rb correctly places bundle exec before ruby app.rb. Others mix order incorrectly.

3. Final Answer:

   bundle exec ruby app.rb -> Option A

4. Quick Check:

   bundle exec before command = C [OK]

Hint: Put 'bundle exec' right before the command you want to run [OK]

Common Mistakes:

• Swapping order of bundle exec and ruby
• Inserting exec or bundle in wrong places
• Omitting bundle exec entirely

3.

Given a Ruby project with a Gemfile specifying rspec version 3.10.0, what will be the output of running rspec --version vs bundle exec rspec --version if the system has rspec 4.0.0 installed globally?

medium

A. rspec --version shows 4.0.0, bundle exec rspec --version shows 3.10.0

B. rspec --version shows 3.10.0, bundle exec rspec --version shows 4.0.0

C. Both commands show 4.0.0

D. Both commands show 3.10.0

Solution

1. Step 1: Understand gem version usage

   Running rspec --version uses the system's global gem version, which is 4.0.0 here.

2. Step 2: Effect of bundle exec

   bundle exec rspec --version runs using the project's Gemfile version, 3.10.0, isolating from global gems.

3. Final Answer:

   rspec --version shows 4.0.0, bundle exec rspec --version shows 3.10.0 -> Option A

4. Quick Check:

   bundle exec uses Gemfile version = D [OK]

Hint: Without bundle exec uses global gems; with it uses project gems [OK]

Common Mistakes:

• Assuming both commands show same version
• Confusing global and project gem versions
• Ignoring Gemfile gem isolation

4.

Consider this command run inside a Ruby project folder:
rspec spec/test_spec.rb
The test fails due to a gem version conflict. How can you fix this using bundle exec?

medium

A. Run gem install rspec to update the gem globally

B. Run bundle exec rspec spec/test_spec.rb to use project gems

C. Run rspec --update to fix conflicts automatically

D. Delete the Gemfile and try again

Solution

1. Step 1: Identify cause of failure

   Failure is due to gem version conflict between global and project gems.

2. Step 2: Use bundle exec to isolate gems

   Running bundle exec rspec spec/test_spec.rb forces use of project Gemfile gems, resolving conflicts.

3. Final Answer:

   Run bundle exec rspec spec/test_spec.rb to use project gems -> Option B

4. Quick Check:

   bundle exec fixes gem conflicts = A [OK]

Hint: Use bundle exec before commands to fix gem conflicts [OK]

Common Mistakes:

• Trying to update gems globally instead of isolating
• Using invalid rspec options
• Deleting Gemfile which breaks project setup

5.

You have a Ruby project with multiple gems and versions specified in the Gemfile. You want to run a custom Ruby script script.rb that depends on these gems. Which command ensures your script uses the correct gem versions and avoids conflicts?

hard

A. ruby script.rb

B. gem install script.rb

C. bundle exec ruby script.rb

D. bundle install script.rb

Solution

1. Step 1: Understand gem version isolation need

   Running ruby script.rb alone may use system gems, causing version conflicts.

2. Step 2: Use bundle exec to run script with project gems

   bundle exec ruby script.rb runs the script using gems specified in the Gemfile, ensuring correct versions.

3. Step 3: Eliminate incorrect options

   gem install script.rb and bundle install script.rb are invalid commands for running scripts.

4. Final Answer:

   bundle exec ruby script.rb -> Option C

5. Quick Check:

   Use bundle exec to run scripts with project gems = B [OK]

Hint: Always prefix scripts with bundle exec to use project gems [OK]

Common Mistakes:

• Running scripts without bundle exec causing conflicts
• Confusing gem install with running scripts
• Trying to bundle install a script file