fix(ls): Allow string types for type arg & improve type safety

[mitsuki31]

Summary

This pull request delivers a set of improvements to the ls function, focusing on flexibility, type safety, and documentation clarity.

Details

APIs Enhancements

• String Value Support for type Argument:
  Previously, the ls function only recognized lsTypes enum values. This change allows you to use string literals directly corresponding to lsTypes properties for the type argument. This simplifies usage, as shown in the example:

  const files = await ls('./foo', {}, 'LS_F');

  Code above are equivalent with this code:

  const files = await ls('./foo', {}, lsTypes[4]);

  A stricter type checking mechanism has been implemented to prevent unexpected or invalid input for the type argument. This is further supported by the introduction of a dedicated helper function, checkType, for robust type verification.

• Default Type Resolution Refactor:
  This change addresses a minor internal adjustment related to the default type resolution mechanism within the ls function.

Documentation

The API documentation for the ls function has been comprehensively reviewed and updated for better clarity. Additionally, link references have been added to relevant error classes that might be thrown by the API, providing more context for potential issues.

Test Environments

New test cases have been added to comprehensively cover various scenarios:

• Allowing null for the options argument.
• Accepting string values for the type argument.
• Throwing a TypeError for unexpected type values.

This ensures the function behaves as expected under different input conditions. Additionally, this changes enhances the readability of success test case descriptions within the simpletest library by adjusting their text color.

Benefits

• Enabling more flexible usage with string value support for the type argument.
• Enforcing stricter type safety to prevent potential errors.
• Providing clearer and more informative documentation for developers.
• Adding comprehensive test cases to guarantee code quality and reliability.