Clamp view_range end to file length and emit warning instead of error (fixes #154)

[xingyaoww]

Summary

• Change OHEditor.view to clamp end_line to the file's length when the provided view_range end is beyond EOF.
• Preserve -1 semantics (end of file).
• Append a clear NOTE warning to the output when clamping occurs instead of raising an error.

Why
Fixes #154: Previously, requesting a range beyond EOF raised an error. The desired behavior is to show up to the end of the file and warn the user.

Changes

• openhands_aci/editor/editor.py
  • Normalize end_line: if -1 use EOF; if > num_lines, cap to num_lines and set a warning message.
  • Ensure end_line >= start_line after normalization.
  • Append a NOTE: We only show up to {num_lines} since there's only {num_lines} lines in this file when clamping occurs.
• tests/integration/editor/test_error_handling.py
  • Update out-of-bounds test to assert on NOTE warning instead of the old error message.

Testing

• Ran selective tests due to environment memory constraints:
  • tests/integration/editor/test_error_handling.py: PASS
  • tests/integration/test_oh_editor.py: PASS
  • tests/integration/editor/test_non_utf8_operations.py: PASS
• pre-commit hooks (ruff, format, mypy) all passed.

Notes

• Full pytest run hit a container MemoryError unrelated to these changes; the relevant tests covering the change pass.

Co-authored-by: openhands openhands@all-hands.dev

@xingyaoww can click here to continue refining the PR