When requiring local files in Ruby, using require with relative paths creates fragile code that depends on the current working
directory and Ruby’s load path configuration.
The require method resolves paths by searching through Ruby’s load path ($LOAD_PATH) and the current working directory.
However, since Ruby 1.9, the current directory (".") was removed from the default load path for security reasons. This means that require
'local_file' or require './local_file' will fail with a LoadError when the script is executed from a different
directory or when the current directory is not explicitly added to the load path.
This creates several problems:
- Execution context dependency: The same script may work when run from one directory but fail when run from another
- Deployment fragility: Code that works in development may break in production due to different execution contexts
- Testing complications: Tests may pass or fail depending on the directory from which the test runner is executed
- Maintenance burden: Developers may resort to modifying the global
$LOAD_PATH or implementing workarounds, which
pollutes the global state
The issue is particularly common in Ruby applications where files need to load other files from the same project, such as utility modules,
configuration files, or related classes.
What is the potential impact?
Applications may fail to start or function correctly when deployed or executed from different directories, leading to LoadError
exceptions in production environments. This can cause service outages and make the codebase difficult to maintain and test reliably.
