fix(overlay): resend signal history after a failed push and sweep element ids

[erkamyaman]

What was wrong

1. The NativeScript overlay left historyDelta true when a push-signal-graph call failed. The catch block rolled the history back and cleared lastSignalKey, so the retry sent a delta against history the server never received. overlay-angular-native.ts already resets it.
2. byId in element-id.ts was only pruned by pruneElementIds(), whose only caller is the component tree builder. With the Components inspector off, defer-blocks, router-links, component-pick, cd-overlay and the overlay still call elementId(), so the map grew without bound.

Root cause and change

• packages/devtools/src/overlay-nativescript.ts: the catch block now sets historyDelta = false, so the next push is a full history.
• packages/devtools/src/element-id.ts: elementId sweeps dead and disconnected entries when byId.size reaches a threshold (512 at first, then twice the surviving size after each sweep). The sweep uses the predicate the last pruneElementIds call passed (default isConnected), so NativeScript views, which have no isConnected, are not dropped. The public API is unchanged. elementIdCount() is a new export used by tests.
• Ids stay stable: ids are in a WeakMap, and live connected elements are never removed.

Tests

• __tests__/overlay-nativescript-signal-push.test.ts: first push sends history, the next sends historyDelta, a failed push is followed by a push with history and no historyDelta. Failed before the fix.
• __tests__/element-id.test.ts: the map stays bounded under 5000 detached elements with no prune, connected elements keep their ids across sweeps, and a custom predicate from pruneElementIds is honored by automatic sweeps.

Verification

pnpm test:devtools (1259 passed), pnpm test:panel (126 passed), pnpm typecheck (exit 0, only existing NG8107 warnings in app), prettier on touched files, pnpm skills:check, pnpm commit:check. Nothing in app/ changed.

Summary by CodeRabbit

• Bug Fixes
  • Element IDs for detached elements are now periodically pruned, limiting retained IDs while preserving IDs for connected elements, including non-host elements.
  • After a failed signal-graph update, the next successful update sends the full history to keep the displayed signal history complete.
  • Signal history updates now retain stable element IDs through repeated insertions, and lookups safely handle objects without connection status or unavailable references.

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Reviewing files that changed from the base of the PR and between 7fa5af5 and 68eb588.

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📒 Files selected for processing (2)

• packages/devtools/src/__tests__/element-id.test.ts
• packages/devtools/src/element-id.ts

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📝 Walkthrough

Walkthrough

The changes add threshold-based cleanup for element IDs and expose the current ID count. They also reset NativeScript signal-history delta mode after a failed push, with tests covering both behaviors.

Changes

Element ID cleanup

Layer / File(s)	Summary
Element ID sweeps and retention packages/devtools/src/element-id.ts, packages/devtools/src/__tests__/element-id.test.ts	elementId triggers sweeps at a dynamic threshold. pruneElementIds saves the connectivity check for later sweeps, and elementIdCount returns the map size. Tests cover detached-element churn, connected element retention, and reuse of the supplied check.

NativeScript signal push recovery

Layer / File(s)	Summary
Signal-history push recovery packages/devtools/src/overlay-nativescript.ts, packages/devtools/src/__tests__/overlay-nativescript-signal-push.test.ts	On RPC failure, pushSignalGraph clears historyDelta along with rolling back collected history and clearing the cached graph key. Tests cover full-history and delta pushes, then verify that a successful push after failure sends full history.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~15 minutes

Change: Bug fix

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Merge Risk

Merge Risk: 🔵 Low · up to 7fa5a

Some Devtools element lookups may temporarily fail after an automatic sweep. The PR is mergeable with owner awareness of this bounded risk.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 7fa5a

The changes improve cleanup and sequential retry recovery without adding privileges or externally exposed operations. Concurrent reporting and shutdown during an active request remain incompletely verified, but no introduced security issue was established.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The changed state is confined to the existing devtools registry instance and diagnostic history carried over the existing NativeScript connection. No new sensitive operation or package entrypoint was established by the inspected changes; page-keyed history storage alone is not evidence of authenticated isolation.

Trust Boundaries and Controls

• observed — ID lookup still applies a connectivity predicate rather than returning any referenced object unconditionally. NativeScript adds host-type and page checks at the highlight consumer, providing counterevidence against cleanup changes expanding target authority.

Resilience and Maintainability Implications

• inferred — Timer-driven reports and selection-triggered pushes can overlap while sharing history cursors and delta flags. Disposal stops future timer ticks but does not explicitly await active reports. These scheduling patterns predate this PR; the added test verifies sequential recovery only, and unavailable transport ordering and cancellation semantics prevent concluding that overlap or interrupted cleanup is safe or worsened.

Hardening Proposals

• proposed — As optional failure-containment hardening, establish per-session delivery ordering and drain or cancel active reports before cleanup. If the transport does not provide these guarantees, serialize history commits or use generation-aware recovery. This is a proposal for existing behavior, not an observed PR-introduced vulnerability.

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Pre-merge checks | 4 | 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 8 functions across 4 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly summarizes both primary fixes: retrying signal history after a failed push and sweeping stale element IDs.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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Inline comments:
Review comments at @packages/devtools/src/element-id.ts:
- Line 15: Update pruneElementIds and the automatic sweep triggered when byId
reaches sweepAt so predicates are scoped to the owning tree or element type; do
not apply collectComponentTree’s connected-host predicate globally to the shared
ID map. Preserve registered non-host entries so elementById can continue
resolving them without requiring elementId to register them again.

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ℹ️ Review info

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• Configuration used: defaults
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📥 Commits

Reviewing files that changed from the base of the PR and between 8581fd2 and 7fa5af5.

📒 Files selected for processing (4)

• packages/devtools/src/__tests__/element-id.test.ts
• packages/devtools/src/__tests__/overlay-nativescript-signal-push.test.ts
• packages/devtools/src/element-id.ts
• packages/devtools/src/overlay-nativescript.ts

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