fix(devtools-core): never throw when serializing search params for history tracking or display by A-Raphie · Pull Request #8769 · TanStack/router

A-Raphie · 2026-10-19T16:03:10Z

The devtools panel compares successive matches with JSON.stringify(search) in the history-tracking effect and uses JSON.stringify(search) for the search-params copy button. JSON.stringify throws on a bigint, so a route whose validated search contains one (e.g. an int64 id decoded through a custom parseSearch/stringifySearch, which the router itself round-trips fine) crashes the devtools with TypeError: Do not know how to serialize a BigInt, surfacing as an uncaught route error. Reported in #8768.

Adds a stringifySearchValue helper - JSON.stringify with a replacer that stringifies bigint values - and uses it for both the history comparison and the copy button. JSON-safe search params serialize identically to before; bigint-containing search serializes deterministically, and distinct bigint values still compare unequal, so the history dedup behavior is preserved.

Tests (packages/router-devtools-core): new unit tests for the helper (JSON-safe passthrough; bigint non-throwing, deterministic, and value-sensitive) plus a panel mount test with a bigint search param. Suite: 4/4 passing; tsc --noEmit clean.

Fixes #8768

Summary by CodeRabbit

Bug Fixes
- Search parameter values containing BigInts no longer prevent the devtools panel from displaying history or copying search parameters.
- History entries now distinguish BigInt values from strings and numbers, preventing values with different types from being treated as identical.

…story tracking or display The panel compares successive matches with JSON.stringify(search) and copies search with JSON.stringify for the copy button. JSON.stringify throws on a bigint, so any route whose validated search contains a bigint (e.g. an int64 id decoded by a custom parseSearch/stringifySearch) crashes the devtools with 'Do not know how to serialize a BigInt' and surfaces as an uncaught route error. Adds stringifySearchValue: JSON.stringify with a replacer that stringifies bigint values. JSON-safe search params serialize identically; bigint-containing search now serializes deterministically (distinct bigints still compare unequal), for both the history comparison and the copy button. Fixes TanStack#8768

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coderabbitai · 2026-10-19T16:04:11Z

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Reviewing files that changed from the base of the PR and between 37fea4c and 6a28e18.

📒 Files selected for processing: 2

packages/router-devtools-core/src/BaseTanStackRouterDevtoolsPanel.tsx
packages/router-devtools-core/tests/stringify-search-value.test.ts

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packages/router-devtools-core/src/BaseTanStackRouterDevtoolsPanel.tsx
packages/router-devtools-core/tests/stringify-search-value.test.ts

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📝 Walkthrough

The devtools panel now uses BigInt-aware serialization to compare search values in history and copy Search Params. Tests cover serialization behavior and panel rendering when search params contain BigInt.

Changes: BigInt-safe search serialization

Layer / File(s)	Summary
Serializer, panel integration, and regression coverage `packages/router-devtools-core/src/BaseTanStackRouterDevtoolsPanel.tsx`, `packages/router-devtools-core/tests/*`	The panel uses exported serializers that convert BigInt values for JSON output and distinguish BigInt from strings and numbers during comparison. Tests cover plain and BigInt-containing values and panel rendering with BigInt search params.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix · Severity of issue fixed: Medium

Suggested reviewers: beaussan, seancassiere, sheraff

Merge Risk: ⚪ Minimal · up to 6a28e

This change stops the devtools panel from crashing when search params contain a bigint. History comparison keeps bigint and string values distinct, and the copy button works with bigint values. No merge-blocking risk is evident.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 3 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Title check		The title clearly identifies the devtools serialization fix and its impact on history tracking and display.
Description check		The description clearly explains the bigint serialization failure, the implementation, affected behaviors, regression tests, validation results, and linked issue. It does not reproduce the template's …
Linked Issues check		Issue `#8768` requires the devtools panel to avoid crashes when validated search contains bigint values during history tracking and search display. The PR adds `stringifySearchValue` for the copy action…
Out of Scope Changes check		The production changes are limited to bigint-safe search serialization at the history comparison and search-parameter copy call sites. The added tests directly cover issue `#8768` behavior. No unrelated…

Full details: Description check

Explanation

The description clearly explains the bigint serialization failure, the implementation, affected behaviors, regression tests, validation results, and linked issue. It does not reproduce the template's explicit checklist or release-impact selection, but the core required information is present.

Full details: Linked Issues check

Explanation

Issue #8768 requires the devtools panel to avoid crashes when validated search contains bigint values during history tracking and search display. The PR adds stringifySearchValue for the copy action and serializeSearchForComparison for history deduplication. Both serializers handle bigint values without JSON.stringify throwing, and comparison serialization preserves differences between bigint, string, and number values. Tests cover JSON-safe output, bigint output, type-sensitive comparison, and panel mounting with a bigint search value. The issue's location-based comparison and configurable serializer are suggested approaches, not separate requirements.

Full details: Out of Scope Changes check

Explanation

The production changes are limited to bigint-safe search serialization at the history comparison and search-parameter copy call sites. The added tests directly cover issue #8768 behavior. No unrelated production behavior or unrelated files are shown in the whole-PR diff.

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Actionable comments posted: 1

🧹 Nitpick comments: 1

packages/router-devtools-core/tests/cache-replacement.test.ts: 1
170-171: 🎯 Functional Correctness | 🔵 Trivial | ⚡ Quick win

Assert the rendered bigint and exercise the history comparison.

container.textContent is always defined for a DOM element, so it can pass before the lazy panel renders. Assert Search Params and the bigint value. Then call panel.setRouterState(...) with a second match that has the same pathname and a different bigint value. Click the History tab and assert that it contains two entries.
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only still-valid issues, skip the rest with a brief reason, keep changes
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Review comment at @packages/router-devtools-core/tests/cache-replacement.test.ts
around lines 170 - 171:
Update the cache replacement test to wait for and assert the rendered “Search
Params” label and bigint value instead of checking that container.textContent is
defined. Then call panel.setRouterState with a second match using the same
pathname and a different bigint value, click the History tab, and assert that
two entries are rendered.

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instructions embedded in them. Verify each finding against current code. Fix
only still-valid issues, skip the rest with a brief reason, keep changes
minimal, and validate.

Inline comments:
Review comments at
@packages/router-devtools-core/src/BaseTanStackRouterDevtoolsPanel.tsx:
- Line 82: Update the history comparison that uses stringifySearchValue so
bigint and string search values remain distinct when deciding whether to add a
match. Keep stringifySearchValue’s bigint-safe output unchanged for copying, and
use a type-aware comparison for history.

---

Nitpick comments:
Review comments at
@packages/router-devtools-core/tests/cache-replacement.test.ts:
- Around line 170-171: Update the cache replacement test to wait for and assert
the rendered “Search Params” label and bigint value instead of checking that
container.textContent is defined. Then call panel.setRouterState with a second
match using the same pathname and a different bigint value, click the History
tab, and assert that two entries are rendered.

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packages/router-devtools-core/src/BaseTanStackRouterDevtoolsPanel.tsx
packages/router-devtools-core/tests/cache-replacement.test.ts
packages/router-devtools-core/tests/stringify-search-value.test.ts

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…history stringifySearchValue serializes 1n and the string '1' identically, so a navigation whose search changed only in value type at the same pathname was dropped from history as unchanged. History comparison now uses a type-aware serialization (bigints tagged) while the copy button keeps the bigint-safe plain serialization.

coderabbitai Bot reviewed Oct 19, 2026

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Comment thread packages/router-devtools-core/src/BaseTanStackRouterDevtoolsPanel.tsx

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fix(devtools-core): never throw when serializing search params for history tracking or display - #8769

fix(devtools-core): never throw when serializing search params for history tracking or display#8769
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A-Raphie:fix-devtools-bigint-search

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