Improvement to diffsense.sh

[eonist]

The script is well-structured overall, but here are several improvements you could make:

Error Handling & Robustness

Set strict error handling at the top: Add set -euo pipefail to fail fast on errors and undefined variables.

Quote variable expansions consistently: Several places miss quotes, which could cause issues with spaces in paths (e.g., "$raw_arg" in the parse loop).

Validate required commands exist: Check for git, shortcuts, sw_vers availability before using them.

Code Quality Issues

Fix the typo in error message: Line 294 says "Diffsensee" instead of "Diffsense".

Improve the macOS version check: The requirement for "macOS 26" seems unusually high (macOS Sequoia is version 15). This appears to be an error - consider using a realistic minimum version.

Simplify the status mapping in build_file_summary: The renamed file handling (R*) could break if there are tabs in the path. Consider using --name-status -z with null-terminated output for safer parsing.

Performance Optimizations

• Cache build_diff_excludes output: It's called twice (in build_file_summary and prepare_diff). Generate once and reuse.
• Use array directly in git commands: Instead of building exclude args in a loop, you could use printf -- ':(exclude)%s\n' "${NOISE_PATTERNS[@]}".

UX Improvements

Provide better feedback during processing: Add a spinner or message like "🤖 Generating commit message..." since the LLM call may take time.

Validate commit message quality: Check if the generated message meets basic git conventions (e.g., not empty, reasonable length) before attempting commit.

Support --help anywhere in args: Currently only works as first argument.

Security Considerations

Sanitize input to shortcuts command: The payload is passed via stdin, but consider what happens if the diff contains special characters that could affect processing.

Add option to preview before commit: A --dry-run flag would let users see the generated message without committing.

[eonist]

The linked script cannot be accessed directly from here due to how GitHub serves raw files, so concrete, line‑level suggestions are not possible in this context. However, there are several common improvement areas for Bash helper scripts in git/CLI tools like this that are worth checking and applying to resources/diffsense.sh:[1]

Shell safety

• Add set -euo pipefail near the top to fail fast on errors, unset variables, or broken pipelines where appropriate.[1]
• Ensure every external command is checked for success (e.g. git, curl, osascript, xcrun) and provide a clear, user‑friendly error message when they are missing or fail.[1]

Portability and compatibility

• Make sure the shebang explicitly targets the intended shell, for example #!/usr/bin/env bash, and avoid Bash‑specific features if /bin/sh is used.[1]
• Check for macOS and architecture specifics (Apple Silicon vs Intel) and guard any xcrun, swift, or Apple Intelligence–specific calls with OS and version checks so the script fails gracefully on unsupported systems.[1]

Argument parsing and UX

• Use a simple getopts loop for flags like -h/--help, --version, --debug, or --no-open instead of manual $1 inspection, which quickly becomes brittle.[1]
• Provide a concise usage() function with examples (e.g. running from inside a git repo vs passing a path) and call it on incorrect arguments.[1]

Git interaction robustness

• Verify that the current directory is inside a git repository before running git commands, and give a clear message if not.[1]
• When generating diffs, explicitly handle staged vs unstaged changes (e.g. git diff --cached vs git diff) and consider a --staged flag so the script does what users expect in both cases.[1]

Error handling and logging

• Centralize error exits in a small helper, for example die() { printf '%s\n' "$*" >&2; exit 1; }, and use it everywhere instead of scattered echo + exit calls.[1]
• Add an optional --debug mode that prints commands and intermediate files/paths to help diagnose issues without overwhelming normal users.[1]

Security and temp files

• Use mktemp for any temporary files rather than predictable names in /tmp, and ensure they are removed via trap 'rm -f "$tmpfile"' EXIT.[1]
• Quote all variable expansions, array expansions, and command substitutions to avoid word‑splitting and globbing issues, especially around paths and git output.[1]

If you paste the contents of diffsense.sh here, more precise, line‑specific suggestions can be provided (including concrete refactors, improved messages, and any Apple‑specific checks that match what the script currently does).

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[eonist]

The diffsense script is well-structured overall, but here are several improvements you could make:

Error Handling & Robustness

• Add set -euo pipefail at the top to catch errors early and prevent undefined variable usage
• Quote all variable expansions to prevent word splitting issues (e.g., "$DIFFSENSE_MAX_CHARS" instead of $DIFFSENSE_MAX_CHARS)
• Check for required commands before execution (verify git, shortcuts, sw_vers, etc. exist)

Code Quality Issues

• Typo in error message: Line 331 says "Diffsensee" instead of "Diffsense"
• Missing help option: The -h|--help check happens too late in the flow—it should be the very first thing checked before any processing
• Inconsistent argument parsing: The script removes leading dashes but doesn't handle -h vs --help consistently with other flags

Performance & Efficiency

• Avoid multiple calls to build_diff_excludes: Currently called twice (in build_file_summary and prepare_diff). Cache the result once
• Simplify numstat parsing: The nested loop for matching paths is inefficient. Consider using git diff --cached --stat or processing in a single pass
• Use mapfile instead of while loop: For reading build_diff_excludes output into arrays

Security Concerns

• Unvalidated user input in read: The check_git_state function uses read -r without timeout, which could hang in non-interactive contexts
• Command injection risk: Although minimal, using shortcuts run with user-controlled diff content should be validated

Functional Improvements

• Add dry-run mode: Allow users to preview the commit message without committing
• Support custom prompts: Let users provide their own prompt templates
• Better error messages: When truncation occurs, notify the user that the diff was too large
• Add version flag: Include --version to show the script version

Example Improvements

# At the top of the script
set -euo pipefail

# Check required commands
for cmd in git shortcuts sw_vers; do
  if ! command -v "$cmd" &>/dev/null; then
    echo "❌ Required command not found: $cmd"
    exit 1
  fi
done

# Cache exclude args globally
readonly DIFF_EXCLUDES=($(build_diff_excludes))

The script is functional and well-commented, but these improvements would make it more robust, maintainable, and user-friendly.