The 4 patcher-fired-but-malformed_response failures showed extract_diff_json
was too strict: it required {"diff": "..."} as the top-level JSON shape
with at most 1 brace nesting depth (regex-based). Real model output
varies more.
Now handles:
1. Bare JSON {"diff", "explanation", "confidence"}
2. Fenced JSON: ```json {…} ```
3. Fenced diff + prose: ```diff …unified diff… ``` + loose explanation
4. Bare unified diff (no JSON wrapper, no fence)
5. JSON with deeply-nested {} inside the diff string (struct literals,
function bodies)
Fixes:
- Replaced regex-based balanced-{} matcher (capped at depth 1) with a
string-aware depth-tracking generator that handles arbitrary nesting
+ skips brace chars inside JSON string literals
- Walk all fenced blocks not just the first; recognize ```diff and
```patch language tags
- Fall back to fenced-diff-with-prose construction when no JSON form
matches — synthetic payload with surrounding text as explanation
- Final fallback for bare unified diffs (no fence, no wrapper) using a
simple line-prefix detector
- Normalize alternate keys (patch, content, diff_text → diff)
- Always set confidence (defaults to medium when absent, low for bare
diffs that have no model commentary)
Tests: 16 → 20 (5 new shape coverage tests). All green.
Kayos
3273d66003