Content preview for Write/Edit tools

[djdarcy]

Summary

Show first ~20 characters of content for Write and Edit operations to help identify what was written without checking the files.

Current Behavior

[[2026-02-01 18:55:36]] {Write: "C:\code\file.txt" }
[[2026-02-01 18:55:56]] {Edit: "C:\code\file.txt" }

Only path is logged.

Desired Behavior

[[2026-02-01 18:55:36]] {Write: "C:\code\file.txt" ← "# Session Logger..." }
[[2026-02-01 18:55:56]] {Edit: "C:\code\file.txt" ← "def main():\n    ..." }

Arrow indicates content direction, preview truncated at ~20 chars with ....

Implementation Notes

• For Write: use content field
• For Edit: use new_string field (the replacement text)
• Escape newlines as \n for single-line display
• Handle binary/non-printable content gracefully
• Truncate with ... if over limit
• Do NOT log old_string (user can check git diff)

Considerations

• 20 chars is a balance between useful and compact
• Could be made configurable in future (Feature: User-configurable logging channels and file routing #1)
• Must preserve single-line scannable format

Analysis

See 2026-02-01__19-10-22__session-logger-enhancements-analysis.md for detailed analysis.

[djdarcy]

✅ Implemented in v0.1.4

Content preview is now logged for Write/Edit operations:

{Write: "path/file.txt" ← "# My Header\nThis..." }
{Edit: "path/file.txt" ← "def new_func():\n..." }
{MultiEdit: "path/file.txt" ← 3 edits }

Features:

• First 20 characters of content shown
• Newlines escaped as \n
• Non-printable characters replaced with ?
• MultiEdit shows edit count instead of content

Ready to close once v0.1.4 is released.

[djdarcy]

Enhancement: Line Count Indicators

Adding line count information to Write/Edit logging for quick assessment of change scope.

Proposed Format

{Write: "path" ← "preview..." (142L)}       ← 142 lines written
{Edit: "path" ← "preview..." (-3/+5L)}      ← 3 lines removed, 5 added
{Edit: "path" ← "preview..." (5L)}          ← same line count (pure replacement)

Implementation

Simple calculation from existing content:

# Write - total lines
lines = len(content.splitlines())

# Edit - delta
old_lines = len(old_string.splitlines())
new_lines = len(new_string.splitlines())
# Show as "-old/+new" or just "N" if equal

Why not actual line numbers?

The tool input doesn't include which line number the edit occurs at. Getting that would require reading the file to find where old_string is located, which:

• Adds I/O overhead
• Could fail if file changed between edit and our read
• Adds complexity for marginal benefit

Line counts give a quick sense of change scope without this complexity.

[djdarcy]

Enhancement: Line Number for Edit Tool

Added file:line format for VS Code clickability - clicking jumps directly to the edited line.

Implementation

def find_line_number(file_path, search_string, max_file_size=1MB):
    # Read file, find search_string, count newlines before it
    return line_number  # 1-indexed

Output Format

{Edit: "C:\path\file.py:45" ← "preview..." (-3/+5L)}

• file.py:45 - clickable, VS Code jumps to line 45
• (-3/+5L) - 3 lines removed, 5 lines added

Performance Safeguards

• Skips files > 1MB
• Uses errors='replace' for encoding issues
• Returns None on any error (graceful fallback to path-only)

Note

Write tool keeps total line count only (142L) since it always writes from line 1.