test: cover SVG coordinate changes between pointer samples

[tannerlinsley]

What changed

Extend the existing SVG coordinate test to cover ancestor translation, preceding layout movement and scrolling between pointer samples, without resizing or re-rendering the chart.

The matrix mock now captures its coefficients when read, like a browser matrix snapshot. A cached matrix must not appear to update itself through a test closure.

Related to @toomingos's report in #203. This protects existing behavior while the remaining pointer-coordinate optimization is investigated. It does not fix or close the remaining performance report.

Verification

• All 19 pnpm validate tasks pass, including 2,237 main tests, type checks, packed consumers, docs and bundle gates.
• Maintained example builds pass. All 188 regenerated SVG previews are unchanged.
• Chromium, Firefox and WebKit reproduce stale coordinates for all three movements when a matrix is cached until resize or scene update.
• A private mutation run that caches the first matrix fails the extended test by 42.38 px. The real implementation passes.
• No runtime files, package versions, dependencies, bundle budgets or CI jobs change. No Changeset is needed for test coverage alone.

The preview manifest is regenerated because the existing source fingerprint includes test files.

Summary by CodeRabbit

• Tests
  • Expanded coverage for chart coordinate mapping when an SVG moves on screen, including horizontal and vertical movement. This verifies that interactions remain aligned with the chart’s current position, even when its size and rendered scene have not changed. No user-facing functionality changes are included.

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⚠️ No Changeset found

Latest commit: 8873b45

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ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: defaults
• Review profile: CHILL
• Plan: Advanced
• Run ID: eae63dce-2a63-489a-bd71-78a8061585a7

📥 Commits

Reviewing files that changed from the base of the PR and between a66cdbf and 8873b45.

📒 Files selected for processing: 2

• benchmarks/conformance/previews/manifest.json
• packages/charts-core/src/svg-surface.test.ts

Included review availability: This review used your included allowance. Your plan provides up to 4 included reviews per hour; 2 remain after this review.

📝 Walkthrough

The SVG coordinate-mapping test now checks results after horizontal and vertical movement between samples. The conformance preview manifest’s sourceHash value also changed.

Changes: SVG Coordinate Mapping

Layer / File(s)	Summary
Coordinate mapping test updates packages/charts-core/src/svg-surface.test.ts	The test mock accounts for current horizontal and vertical translations. The test checks coordinate mapping after positive horizontal and vertical movement and negative vertical movement.

Conformance Preview Manifest

Layer / File(s)	Summary
Preview source hash benchmarks/conformance/previews/manifest.json	The manifest’s sourceHash value changed.

Priority: ⬇️ Low

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

Change: Other

Merge Risk: ⚪ Minimal · up to 8873b

The added test coverage and manifest update present no identified blocker to merging after normal checks.

Pre-merge checks: 5

Passed checks: 5 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: extending SVG coordinate tests to cover coordinate changes between pointer samples.
Docstring Coverage		No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 1…
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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[nx-cloud]

View your CI Pipeline Execution ↗ for commit 8873b45

Command	Status	Duration	Result
nx run charts-workspace:ci-distributed	✅ Succeeded	2m 24s	View ↗
nx run charts-workspace:package-check	✅ Succeeded	<1s	View ↗
nx run charts-workspace:benchmark-check	✅ Succeeded	46s	View ↗

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☁️ Nx Cloud last updated this comment at 2026-10-14 05:33:32 UTC