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Kyle Carberry
5945febf06
Inspired by openai/codex's `apply_patch` implementation, this changes the `edit_files` search-and-replace to use a cascading match strategy when the exact search string isn't found: 1. **Exact substring match** (byte-for-byte) — existing behavior, unchanged 2. **Line-by-line match ignoring trailing whitespace** — handles trailing spaces/tabs the LLM omits 3. **Line-by-line match ignoring all leading/trailing whitespace** — handles tabs-vs-spaces and wrong indentation depth ## Problem When the chat agent uses `edit_files`, it generates a search string that must match the file content exactly. LLMs frequently get whitespace wrong: - Emitting spaces when the file uses tabs (or vice versa) - Getting the indentation depth wrong by one or more levels - Omitting trailing whitespace that exists in the file When this happens, the edit silently does nothing, and the agent falls into a retry loop using `cat -A` to diagnose the exact whitespace characters. ## Solution Adopted the same cascading fuzzy match strategy that [openai/codex uses in `seek_sequence.rs`](https://github.com/openai/codex/blob/main/codex-rs/apply-patch/src/seek_sequence.rs): - Pass 1: exact match (existing behavior) - Pass 2: `TrimRight` each line before comparing (trailing whitespace tolerance) - Pass 3: `TrimSpace` each line before comparing (full indentation tolerance) When a fuzzy match is found, the matched lines in the original file are replaced with the replacement text. This preserves surrounding content exactly. ## Changes - `agent/agentfiles/files.go`: Replaced `icholy/replace` streaming transformer with in-memory `fuzzyReplace` + helper functions (`seekLines`, `spliceLines`) - `agent/agentfiles/files_test.go`: Added 6 new test cases covering trailing whitespace, tabs-vs-spaces, different indent depths, exact match preference, no-match behavior, and mixed whitespace multiline edits - Removed `icholy/replace` dependency from go.mod/go.sum --------- Co-authored-by: Kyle Carberry <kylecarbs@users.noreply.github.com>