How to use the command 'bundle' (with examples)

The command ‘bundle’ is a dependency manager for the Ruby programming language. It allows developers to manage the gems (libraries) their Ruby projects depend on. By using ‘bundle’, developers can easily install, update, and list the gems defined in their project’s Gemfile.

Use case 1: Install all gems defined in the Gemfile expected in the working directory

Code:

bundle install

Motivation: The ‘bundle install’ command is used to install all gems defined in the Gemfile. It ensures that all the necessary gems and their specified version requirements are met, allowing the project to run without any missing dependencies.

Explanation: The ‘bundle install’ command reads the Gemfile in the working directory and installs all the gems defined in it. It also generates a ‘Gemfile.lock’ file, which specifies the exact versions of the installed gems.

Example output:

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Fetching rake 12.3.3
Installing rake 12.3.3
Fetching rspec 3.10.0
Installing rspec 3.10.0
...
Bundle complete! x Gemfile dependencies, x gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.

Use case 2: Execute a command in the context of the current bundle

Code:

bundle exec command arguments

Motivation: The ‘bundle exec’ command is used to execute a command within the context of the current bundle. It ensures that the command is run with the correct gem versions specified in the Gemfile, avoiding conflicts or compatibility issues with other installed gems.

Explanation: The ‘bundle exec’ command is followed by the desired command and its arguments. It runs the command within the context of the bundle, using the gems specified in the Gemfile.

Example output:

bundle exec ruby main.rb

Use case 3: Update all gems by the rules defined in the Gemfile and regenerate Gemfile.lock

Code:

bundle update

Motivation: The ‘bundle update’ command is used to update all gems to their latest versions according to the rules defined in the Gemfile. It ensures that the project is using the most up-to-date gem versions and regenerates the ‘Gemfile.lock’ file accordingly.

Explanation: The ‘bundle update’ command reads the Gemfile and updates all gems to their latest versions. It then generates a new ‘Gemfile.lock’ file, specifying the exact versions of the updated gems.

Example output:

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using rake 13.0.1
Using rspec 4.0.0
...
Bundle updated!

Use case 4: Update one or more specific gem(s) defined in the Gemfile

Code:

bundle update gem_name1 gem_name2

Motivation: The ‘bundle update’ command allows developers to update specific gems to their latest versions without updating all gems in the project. This is useful when a specific gem needs to be updated due to bug fixes or new features.

Explanation: The ‘bundle update’ command followed by one or more gem names updates only those specified gems to their latest versions, following the rules defined in the Gemfile. It regenerates the ‘Gemfile.lock’ file with the updated gem versions.

Example output:

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using rake 13.1.0
Using rspec 4.1.0
...
Bundle updated!

Use case 5: Update one or more specific gem(s) defined in the Gemfile but only to the next patch version

Code:

bundle update --patch gem_name1 gem_name2

Motivation: The ‘–patch’ option allows developers to update specific gems defined in the Gemfile to their next patch version only. This helps in ensuring that only backward-compatible bug fixes are applied without introducing any new features or breaking changes.

Explanation: The ‘bundle update’ command followed by the ‘–patch’ option and one or more gem names updates the specified gems to their next patch versions. It considers the rules defined in the Gemfile and generates a new ‘Gemfile.lock’ file.

Example output:

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using rake 13.0.2
Using rspec 4.0.2
...
Bundle updated!

Use case 6: Update all gems within the given group in the Gemfile

Code:

bundle update --group development

Motivation: The ‘–group’ option allows developers to update all gems within a specific group defined in the Gemfile. This is beneficial when working on specific development-related gems that are not required in the production build of the project.

Explanation: The ‘bundle update’ command followed by the ‘–group’ option and the name of the group updates all the gems within that group to their latest versions. It considers the rules defined in the Gemfile and generates a new ‘Gemfile.lock’ file.

Example output:

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using rake 13.0.1
Fetching byebug 11.1.4 (x86_64-linux)
...
Bundle updated!

Use case 7: List installed gems in the Gemfile with newer versions available

Code:

bundle outdated

Motivation: The ‘bundle outdated’ command allows developers to check if there are any newer versions available for the gems installed in the project. This helps in keeping the project up-to-date with the latest bug fixes and features provided by the gems.

Explanation: The ‘bundle outdated’ command lists all the installed gems in the Gemfile that have newer versions available. It also displays the currently installed version and the latest version of each gem.

Example output:

Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Outdated gems included in the bundle:
  * rspec (3.10.0 < 4.0.0)

Use case 8: Create a new gem skeleton

Code:

bundle gem gem_name

Motivation: The ‘bundle gem’ command is used to quickly generate the basic skeleton structure for creating a new gem in Ruby. It provides a convenient starting point for developing and publishing a Ruby gem.

Explanation: The ‘bundle gem’ command followed by the desired ‘gem_name’ creates a new directory with the specified name and generates the necessary files and boilerplate code for a gem. This includes files like the gemspec, README, and basic test files.

Example output:

      create  gem_name/Gemfile
      create  gem_name/lib/gem_name.rb
      create  gem_name/lib/gem_name/version.rb
      create  gem_name/LICENSE.txt
      ...

Conclusion:

In this article, we explored different use cases of the ‘bundle’ command, which is a dependency manager for the Ruby programming language. By using these examples, developers can effectively manage and update the gems in their Ruby projects, ensuring proper dependencies and keeping their projects up-to-date with the latest gem versions.