fix: reject distinct ambiguous mutation targets

[thymikee]

Summary

Fail mutating selectors closed when same-label matches belong to distinct accessibility subtrees, while preserving benign React Native wrapper chains by collapsing only a single ancestor-descendant chain that resolves to one actionable node.

The direct iOS path now counts raw exact matches before hittability and delegates ambiguous matches to the shared runtime. Rejections publish a bounded partial ref frame across CLI and MCP so an agent can immediately retry with a pinned @ref.

Root cause: the mutation policy used geometric disambiguation, so element-14 silently selected one of the distinct Team Standup targets. The #1597 candidate renderer had shipped, but this interaction path neither rejected nor published candidates.

The scope crosses selector policy, runtime and direct-iOS guarantees, CLI/MCP recovery, contract coverage, ADRs, help, and changelog.

Validation

• Exact pushed head edc2c96c: VITEST_MAX_WORKERS=2 pnpm check:affected --run passed all selected checks and 4,014 tests; fresh iOS and macOS XCTest builds succeeded. The worker cap only reduced host contention; no timeout or assertion was relaxed.
• Live Element-14 proof on the immediately preceding rebased head 64d08193 (the selector patch is unchanged in edc2c96c; the final rebase only incorporates fix(test): clean Swift toolchain temporary directories #1664's Swift test temporary-directory cleanup): in-room press 'label="Team Standup"' failed closed before mutation with AMBIGUOUS_MATCH, five distinct candidates, and refsGeneration: 440518. Retrying press @e13~s440518 succeeded and opened the intended room-history screen.
• Replay shadow on rebased head 01b3c7478: the 39-flow React Navigation Maestro suite passed 39/39 in 1092.3s, each on one attempt with zero heals.
• A repeat replay on 64d08193 was invalidated by host infrastructure: CoreSimulatorService/simdiskimaged crashed after 22 passing flows (connection invalid, BUILD INTERRUPTED), then the target shut down and the remaining flows failed at stopApp. This is not claimed as a product pass. Repeated read-only simctl list calls continued to reproduce the host service crash, preventing a trustworthy final-head rerun without disrupting other simulator work.
• Element sessions were closed and disposable Element clones deleted. No simulator named bench-golden* was booted or targeted. One disposable React Navigation simulator remains pending deletion once CoreSimulatorService stabilizes.

[github-actions]

Size Report

Metric	Base	Current	Diff
JS raw	1.99 MB	1.99 MB	+2.2 kB
JS gzip	642.6 kB	643.4 kB	+751 B
npm tarball	770.6 kB	772.6 kB	+2.0 kB
npm unpacked	2.70 MB	2.70 MB	+5.6 kB

Startup median (7 runs, lower is better):

Scenario	Base	Current	Diff
CLI --version	26.7 ms	27.3 ms	+0.7 ms
CLI --help	65.0 ms	65.4 ms	+0.4 ms

Top changed chunks:

Chunk	Raw diff	Gzip diff
dist/src/prepare-kind.js	+1.5 kB	+499 B
dist/src/cli-help.js	+269 B	+110 B
dist/src/interaction.js	+279 B	+106 B
dist/src/internal/daemon.js	0 B	-2 B
dist/src/runtime.js	0 B	-2 B

[thymikee]

Review: code is clean. The fail-closed structural policy, candidate publication/MCP pinning, and direct-iOS fallback align with ADRs 0010, 0011, 0012, and 0014; all CI checks are green.\n\nThis is not merge-ready yet. The required exact-head 39-flow replay/device evidence against the actual Element-14 motivating state is still missing, including both the ambiguous rejection and retry using a returned pinned ref. The reported synthetic gearshape.fill simulator run does not validate that motivating path. Please attach that replay/device evidence, then request re-review.

[thymikee]

Required exact-head evidence is now complete on 01b3c7478 after rebasing onto current main:

• Element-14 motivating state: on a disposable non-golden clone, the in-room mutation press 'label="Team Standup"' returned AMBIGUOUS_MATCH with five distinct candidates (text, disabled text-field, table, cell, button) and refsGeneration: 805389. The screen did not mutate.
• Pinned recovery: retrying the returned button candidate as press @e13~s805389 succeeded and opened the intended Team Standup room-history screen.
• Replay shadow: the 39-flow React Navigation Maestro suite passed 39/39 in 1092.3s on the non-golden iPhone 17 Pro simulator. JUnit records failures="0", skipped="0"; every flow used one attempt and zero heals.
• Local gate: VITEST_MAX_WORKERS=4 pnpm check:affected --run passed all selected checks and 3,995 tests. The worker cap only reduced host contention; no timeout or assertion was relaxed.
• Cleanup: sessions/daemons closed, delegated XCTest runners terminated, disposable Element clone deleted. No simulator named bench-golden* was booted or targeted.

The earlier pre-rebase replay and the initial runner-handoff attempt are not claimed as exact-head evidence. This result is from the pushed rebased head. Ready for re-review once the refreshed GitHub checks complete.

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-08-07 13:47 UTC

[thymikee]

Re-reviewed exact head 01b3c7478. The substantive patch is unchanged apart from expected rebase reconciliation, and the prior evidence blocker is closed: exact-head Element-14 ambiguity rejected with five candidates and no mutation, the pinned returned ref opened the intended room, and the replay shadow passed 39/39 with zero heals. Code and practical evidence are clean. The remaining blocker is branch state: GitHub reports DIRTY/CONFLICTING against current main (the merge-tree conflict is additive CHANGELOG.md). Rebase/resolve, then request a changed-head re-review.

[thymikee]

Re-reviewed exact head 64d081931: range-diff shows the substantive selector patch is identical to reviewed head 01b3c747, so the code verdict remains clean and the existing Element-14/pinned-ref/39-flow evidence remains materially probative. The branch is still DIRTY/CONFLICTING against current main; merge-tree shows the additive CHANGELOG.md conflict. Resolve/rebase and request changed-head review. The device replay need not be repeated if the next range-diff remains patch-identical and base reconciliation is orthogonal.

[thymikee]

Final rebase is published at edc2c96c and is mergeable against current main. Exact-head affected gates pass 4,014/4,014 and fresh iOS/macOS XCTest builds pass. The Element-14 fail-fast + pinned-ref recovery proof was repeated on the immediately preceding rebased head 64d08193; the selector patch is byte-for-byte unchanged, and the final rebase only adds #1664 Swift test temp-directory cleanup. The PR body now records the prior 39/39 replay and the later CoreSimulatorService/simdiskimaged crash transparently. Fresh GitHub checks, including all four CodeQL languages, are running. Ready for re-review once they complete.

[thymikee]

CI babysitting update: every check except iOS smoke is green. iOS smoke failed three times in the pre-existing hidden-keyboard XCTest area, never in selector ambiguity code: (1) partial text "h" vs "hardware-keyboard"; (2) a different Xcode runner-app launch timeout while the first test passed; (3) the same partial-text assertion. PR #1676 (fix(test): wait for typed text to settle in the hidden-keyboard runner test) already fixes this exact assertion and is fully green/mergeable. I am not copying that unrelated fix into this PR; once #1676 lands on main, this branch can rebase and rerun cleanly.

[thymikee]

Correction to the prior note: #1676 identifies the same failing test but is not an acceptable unblock as written; its post-response polling weakens the production-route oracle (see the P1 review there). #1673 attempted the production fix but was closed with work continuing elsewhere. The important classification is unchanged: this PR does not touch RunnerTests+CommandExecution.swift or synthesized-first-responder typing, and the only red check is exposing that known baseline production timing bug. No unrelated workaround belongs in #1667.

[thymikee]

P2 — scope raw-match rejection to mutations; it currently changes direct read behavior too.

RunnerTests+Interaction.findElement now applies classifyDirectSelectorCandidates(... allowNonHittableFallback: false) to querySelector as well as press/type. With one visible/hittable match and one non-hittable same-selector duplicate, the query now returns AMBIGUOUS_MATCH; before this change it selected the hittable element. queryDirectIosSelectorOrFallback preserves AMBIGUOUS_MATCH for read callers, so wait and is surface the error instead of using their prior behavior/tree path.

Keep the new raw-match rule on mutation dispatches only, or give querySelector its prior read policy (alternatively fall back to runtime resolution for the read). Please add coverage for that one-hittable + one-non-hittable read case.

[thymikee]

P2 fixed in 9e1ffb2 — the raw-match rejection is now scoped to mutating dispatches.

classifyDirectSelectorCandidates takes a rawMatchPolicy:

• .rejectDistinctMatches (the default, so no mutation call site changed) keeps the fail-closed rule: every raw exact match counts before hittability can pick a winner.
• .preferHittableMatch restores the prior read rule — prefer the single hittable match, ambiguous only when hittable matches compete, and never adopt the Maestro coordinate fallback.

queryElement passes .preferHittableMatch. The Maestro expected-point / non-hittable path is untouched: when allowNonHittableFallback is true the policy is not consulted, so that branch is byte-identical in behavior.

Coverage in RunnerTests+SelectorMatchPolicyTests.swift, including the case you named:

• one hittable + one non-hittable same-selector duplicate → .selected(index: 0), not .ambiguous
• two hittable matches → still .ambiguous
• non-hittable only → .noMatch, i.e. a read does not borrow the coordinate fallback

ADR 0011's 2026-08-07 amendment previously read as if the raw-match rule covered the whole direct XCTest path; it now says mutating dispatches only and states the read rule and why (get/is/wait sit behind querySelector, and a read has no side effect to guard).

Honest limits on this head. This was authored in a Linux container: there is no Swift toolchain and no Xcode, so the change is not compiled or run locally — the iOS Smoke lane is the first build. There is no simulator here either, so no device evidence: the one-hittable + one-non-hittable read has not been observed end-to-end through get/is/wait on a real screen. check:fallow passes on the 40 changed files; the TS side is unchanged by this commit.

---

Generated by Claude Code

[thymikee]

Code routing is corrected at 9e1ffb2, but not ready yet. The three new SelectorMatchPolicy Swift regressions are compile-only: ios.yml runs an explicit -only-testing list and none is included. They also test only the classifier, so deleting queryElement’s .preferHittableMatch wiring leaves them green. Add an executed route-level querySelector/get/is/wait regression with red-before proof (and include it in the targeted XCTest gate), then attach exact-head iOS evidence for the one-hittable + non-hittable duplicate read path. Mutation routes correctly retain fail-closed behavior.