ASYNC_OUTSIDE_LOADING_BOUNDARY
Async computation outside Loading boundary (non-halting; root mount is deferred).
What you saw
- Kind:
async - Severity:
warn(code that works but is structurally wrong or expensive)
The console report opens with [ASYNC_OUTSIDE_LOADING_BOUNDARY] and the message, then an in line naming the owners that enclose the subject, root first, and an at line with the source location when the code was compiled with one.
In a captured artifact the same finding is an event with code: "ASYNC_OUTSIDE_LOADING_BOUNDARY", ownerPath, and loc.
Diagnostics explains each line.
Why it fires
On the client, an async value was read outside a Loading boundary during mounting. The root mount waits until the pending async work settles.
How to fix it
Put the pending content inside <Loading> and provide a fallback if the page should show something while it waits.
During SSR, reading a source declared with ssrSource: "client" outside <Loading> throws an error because the server cannot run that source.
Wrap the read in <Loading> to provide a fallback, or declare loadingValue/seedLoadingValue to render a provisional value.
In tests
captureArtifact from @solidjs/diagnostics runs a scenario with the diagnostics channel open and returns the events it saw.
expectNoDiagnostics(artifact) fails while ASYNC_OUTSIDE_LOADING_BOUNDARY is among them, with the events as evidence; after the fix, the code is gone from artifact.diagnostics.
Check for regressions in tests shows the loop and the Vitest matcher form.
Learn more
- Diagnostics: every code, with its kind, severity, and trigger.
- Debugging reactivity: how to read a report and what each group of codes points at.