using cursor agent to assess based on the per branch changes and line by line with git blame, what are the key differences, and what are the newer changes, and if it is newer changes by only another author (not me) then to accept main branch / newest changes as the correct path to merge.
dealing with basic / dumb diffs
problem: you get something complex like package.json. it says local branch, nearly the entire file, then main branch, again entire thing repeated. this makes it very difficult for a human to quickly assetain what is different and what matters. Worst case you get many blocks like this with just some whitespace or block markers in between, further obfusicating the issue.
Git is dumb in this respect and doesn’t help you. And thus, tools like the diff view in Cursor IDE / VS Code will not further help.
exploring at the recomendation of gpt using difftastic (nice name) and merge-rs (same author, this specific use case) a way to rewrite the merge markers to me more meaningful.
dealing with rust
going on a tangent with gpt suggesting rustup vs. brew rust to run these. I am going to stick with homebrew rust for now with an eye on rustup for the future. I am not super entusiastic as there is not a brew formula ready for this approach and it requires some curl direct shell install, not my favorite. maybe I will come back to this.
merge-rs
this requires a custom install by cloning the libary and a manual build. For future reference I will install these in ~/workspace/bin why ~/workspace, a method I took from another dev recently that allows more isolation and portability than installing everything in ~/ (home).
turns out this was hallunicated
difftastic will do this in the terminal, it is okay, but not the best.
gpt suggests semanticdiff extension for vs code. both cursor and vscode both fail and never show the diff. product is paid, so maybe not the best fit. it is also not clear it solves the issue I am having from a quicklook at the home page.
SemanticDiff - Language Aware Diff For VS Code & GitHub
Prompt use difft (difftastic rust cli) to get surgical change information from a basic / dumb merge or rebase conflict with overly broad markers
When analyzing merge conflicts, use `difft` with JSON output to get structured diff data:
1. Extract both versions of the conflicted file:
git show :2:path/to/file > /tmp/file-head.json
git show :3:path/to/file > /tmp/file-incoming.json
1. Run difft with JSON output:
DFT_UNSTABLE=yes difft --display=json /tmp/file-head.json /tmp/file-incoming.json
1. The JSON provides structured chunks with:
- Exact line numbers for each change
- Highlighting information showing what changed
- Clear lhs/rhs (left-hand-side/right-hand-side) indicators
- Language detection
- Status of changes
This gives you precise, machine-readable diff information instead of parsing conflict markers manually.
Full single-line command example:
DFT_UNSTABLE=yes git show :2:ui/lib/ui-kit/package.json > /tmp/package-head.json && git show :3:ui/lib/ui-kit/package.json > /tmp/package-incoming.json && difft --display=json /tmp/package-head.json /tmp/package-incoming.json