A patch tool's result is a JSON record whose payload IS the diff. In a verbose
session the gateway redacts + TAIL-caps result_text (_cap_tui_verbose_text),
so the echo arrived under the native diff in two broken shapes: truncated
mid-JSON (unparseable, so the old JSON.parse check failed open), or — for tall
edits — capped PAST the JSON head, which the store's normalizeOutput then
un-escapes into plain lines that duplicate the diff. North star: no raw JSON
in the transcript, ever.
Three layers:
- gateway: when diff_unified ships, result_text drops the in-JSON diff echo
(_result_sans_diff_echo) — small, parseable, carries only the non-diff
signal (success/files_modified/warnings/lsp_diagnostics).
- fileTool diffOutputPlan: anything starting with '{' under a rendered diff is
suppressed regardless of parseability; parseable JSON with real non-diff
signal (error/warning/lsp_diagnostics) renders JUST those as labeled notes;
a non-JSON fragment whose lines echo the rendered diff is suppressed too
(guards older emitters). Plain-text results (lint tails) still render.
Expanding a tall <diff showLineNumbers> pinned to the scrollbox bottom froze
the TUI with ERR_INVALID_ARG_VALUE looping out of CliRenderer.loop every
frame. Root cause: @opentui/core 0.4.0 marshals OptimizedBuffer
fillRect/drawText/setCell* coordinates as u32 in the FFI table while
LineNumberRenderable.renderSelf passes raw screen coordinates — NEGATIVE when
the diff is partially scrolled above the viewport. Bun's FFI silently wraps
negatives (native side bounds-checks them into a no-op); Node's experimental
node:ffi rejects them. bufferDrawBox already uses i32, which is why ordinary
boxes/text scroll fine and only the diff line-background path crashed.
Fix at the seam we own: boundary/ffiSafe.ts patches OptimizedBuffer to clip
fillRect to the non-negative quadrant and skip negative-origin
drawText/setCell*/drawChar before the FFI call (Bun parity). Installed from
boundary/renderer.ts (live) and test/lib/render.ts (headless). TODO(upstream):
widen those FFI params to i32 so this shim can be deleted.
Ports the engine off the second JS runtime onto Node 26.3 (node:ffi) so the
repo ships a single JavaScript runtime: child_process for the gateway, vitest
for tests, an esbuild + Solid build step. Mouse selection copies the rendered
text you highlight, and the clipboard path is crash-proofed (a broken copy
pipe no longer quits the UI). Renames the engine dir ui-tui-opentui-v2/ ->
ui-opentui/ and updates the launcher/installer/Docker references.
