yoi/.yoi/tickets/00001KSKBP9YG/artifacts/review-2026-06-13-e2e-harness.md

Request changes.

Evidence reviewed:

• Inspected Ticket record and git diff 134e8b8b..HEAD for commits 96561897 and 10a1c383.
• tests/e2e provides a credible first declarative harness (PanelHarness::spawn, wait_for, wait_for_rows, click, press, expect_selection, expect_exit_within, artifacts/metadata/input/output/event logs). This is not merely a fixed-sleep shell script.
• Mouse-selection scenario waits for rendered rows, verifies both normal mouse and SGR mouse capture before click, sends the click through PTY bytes, waits for selection_changed, and asserts no action_requested dispatch.
• Quit-latency scenario creates a real feature-gated background-task hold barrier, waits until the task is actually waiting before sending Ctrl+C through the PTY, and measures bounded exit latency.
• yoi-e2e is opt-in via package feature/test required-features = ["e2e"]; e2e tests are outside default members. YOI_TUI_TEST_EVENTS and YOI_TUI_TEST_HOLD_BACKGROUND_TASK env behavior is behind tui/e2e-test / yoi/e2e-test feature gates, and the hook is observability-only.

Required change:

• The normal production build still contains/evaluates too much e2e harness glue. In non-e2e-test builds, crates/tui/src/e2e_observer.rs exposes no-op emit/hold functions, but call sites still execute test-specific data construction. In particular App::emit_rows_rendered and its panel row key/rect DTOs are compiled unconditionally and app.emit_rows_rendered() is called from the panel render path, causing row snapshots to be built every draw even though emission is a no-op. Selection/action/quit call sites also construct serde_json::json! payloads before the no-op facade. This violates the recorded boundary that production binaries should not contain harness logic and production-side hooks must be feature-gated/compiled out for normal builds.
  • Please cfg-gate the call sites/helpers/DTOs, or use a lazy cfg-gated macro/helper so normal builds do not evaluate or retain e2e event payload construction. A tiny compile-only facade is acceptable only if it does not execute or allocate e2e-specific work and does not keep harness DTO logic in the normal runtime path.

Validation run in /home/hare/Projects/yoi/.worktree/e2e-harness:

• git diff --check 134e8b8b..HEAD — passed.
• cargo fmt --check — passed.
• cargo check -p tui --all-targets — passed.
• cargo check -p yoi --all-targets — passed.
• cargo build -p yoi --features e2e-test — passed.
• YOI_E2E_BIN=/home/hare/Projects/yoi/.worktree/e2e-harness/target/debug/yoi cargo test -p yoi-e2e --features e2e --test panel -- --nocapture — passed.
• cargo check -p tui --all-targets --features e2e-test — passed.
• cargo check -p yoi --all-targets --features e2e-test — passed.
• cargo check -p yoi-e2e --all-targets --features e2e — passed.

No source changes were made during review.