feat: Add support for path in map fn

[deependujha]

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

Fixes #581

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in GitHub issues there's a high chance it will not be merged.

Did you have fun?

Make sure you had fun coding 🙃

[Copilot]

Pull Request Overview

This PR adds support for using Path objects in the map function, along with a new test for resolving time templates. The key changes include:

• Updating _resolve_dir and map function signatures to accept Path types.
• Adding tests to verify the time template resolution and map functionality.
• Enhancing error messages and type checks for directory inputs.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/streaming/test_resolver.py	Added _resolve_time_template tests
tests/processing/test_functions.py	Added new test for map function using Path as output_dir
src/litdata/streaming/resolver.py	Updated _resolve_dir and _resolve_time_template signatures
src/litdata/processing/functions.py	Updated map function parameter types to support Path

Comments suppressed due to low confidence (1)

tests/streaming/test_resolver.py:402

• Ensure that the 'resolver' variable is properly defined or imported in the test; otherwise, this line may lead to a NameError at runtime.

assert resolver._resolve_time_template(path_1) == f"/logs/log_{curr_year}-{curr_month:02d}"

[Copilot]

Pull Request Overview

This PR adds support for resolving a datetime template in directory paths and extends the map function to handle Path objects.

• Added tests for time-based template resolution in file paths.
• Updated type hints and error messages across resolver and processing functions to support Path objects.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/streaming/test_resolver.py	Added new test (test_resolve_time_template) for datetime resolution.
tests/processing/test_functions.py	Introduced tests for the map function with file path updates.
src/litdata/streaming/resolver.py	Updated _resolve_dir to accept Path objects and improved error messaging.
src/litdata/processing/functions.py	Updated map function signature to support Path types in parameters.

[deependujha]

Hi @SkafteNicki feel free to review the PR.

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 79%. Comparing base (96238b6) to head (bff8a9e).
Report is 1 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #582   +/-   ##
===================================
  Coverage    79%    79%           
===================================
  Files        40     40           
  Lines      6111   6112    +1     
===================================
+ Hits       4809   4815    +6     
+ Misses     1302   1297    -5     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[bhimrazy]

LGTM.
Let's get one more approval before merging.