Graph reports ready before its modules exist, setters crash during init

[hihubbIe]

What happens

isReady is set at the top of the device promise's continuation, right after this.device = device. Since 4afb901 that continuation then awaits luma's first canvas measurement (up to 500 ms) before it builds Points, Lines and the force modules. ensureDevice only checks isReady, so during that wait public methods run instead of queueing, and setPointPositions throws on this.points!.shouldSkipRescale.

Init reaches that window on its own. It applies initialZoomLevel through setZoomLevel with a zero duration; d3-zoom dispatches start / zoom / end synchronously on that path, and the Zoom module forwards them to onZoomStart / onZoom / onZoomEnd before the modules exist. A setter called from one of those callbacks throws inside the setup promise: the .catch logs Device initialization failed:, ready rejects, every queued call logs the same error, and the instance never recovers.

How we hit it

Our app changes level of detail on zoom (node icons hide below a zoom level) and re-uploads buffers from onZoomEnd. Now and then the graph stayed blank: a data update landed in the window and crashed once, then the init zoom-end re-entered the same path and took the whole init down. The console showed the setPointPositions TypeError, then Device initialization failed: once per queued call.

Reproduce (on main)

const graph = new Graph(div, {
  onZoomEnd: () => graph.setPointPositions(new Float32Array()),
})

Every construction logs TypeError: Cannot set properties of undefined (setting 'shouldSkipRescale') followed by Device initialization failed:, and graph.ready rejects.

Fix

• isReady = true moves to the end of the setup body, after the store is configured, so it means what its doc comment says and ensureDevice queues until then. Calls run once ready resolves, in order.
• The init setZoomLevel moves after the flag. Left before it, ensureDevice would queue it onto ready behind consumer
  handlers registered at construction, and it woconsumer's fitView in ready.then.

A null guard in setPointPositions alone would be kept and dontRescale dropped, so the next create() would rescale against the caller's request.

Lint and build pass. A history/ note is included.

See the Pen Cosmos isReady error by Ivan Alglave (@hihubbIe) on CodePen.

Disclosure: Root-cause analysis and this write-up were done with Claude Code. I reviewed the diff, ran lint and build, and reproduced the failure in the linked pen.

Summary by CodeRabbit

• Bug Fixes
  • Fixed an initialization timing issue that could cause updates made during startup to fail.
  • Requests made before the graph is fully ready are now queued and applied after initialization completes.
  • Initial zoom is now applied after all graph components have finished setting up, providing more consistent startup behavior.
  • Improved reliability for interactions and configuration changes made while the graph is loading.

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📝 Walkthrough

Walkthrough

The Graph constructor now sets isReady and applies the initial zoom only after device validation and all setup steps complete. A changelog documents the previous early-readiness behavior and the fix.

Changes

Initialization readiness

Layer / File(s)	Summary
Complete setup before readiness src/index.ts, history/2026/2026-09-17-init-readiness.md	The constructor defers isReady = true and the initial setZoomLevel call until setup completes. The changelog documents the previous early-readiness behavior and its effect on queued setters.

Priority: ⬇️ Low

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

Change: Bug fix · Severity of issue fixed: Low

Merge Risk: ⚪ Minimal · up to 4c264

The documented initialization ordering matches the current behavior, with no actionable merge risk remaining.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	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	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly identifies the main initialization race: the graph reports readiness before its modules exist, which causes setters to fail during initialization.

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Actionable comments posted: 1

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Inline comments:
In `@history/2026/2026-09-17-init-readiness.md`:
- Line 21: Update the readiness-order wording in the history entry to state that
isReady = true is set immediately before the initial setZoomLevel call, rather
than describing it as the last setup step.

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Run ID: 675cc3e0-391d-49e6-bcf1-25e7e1963956

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📒 Files selected for processing (2)

• history/2026/2026-09-17-init-readiness.md
• src/index.ts

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