data.error tells you if the request has errored out; if so, it contains the error thrown by the fetcher.
The second part is not true. There is a castError function that's called which modifies the error thrown by the fetcher, making sure that data.error is always an Error object, and therefore data.error is not always what the fetcher throws:
Describe the bug
https://github.com/solidjs/solid-docs/blob/883f25e17843fff81d002a80e8f9a3344556fdaf/langs/en/api/api.md?plain=1#L403
The documentation linked above says
The second part is not true. There is a
castErrorfunction that's called which modifies the error thrown by the fetcher, making sure thatdata.erroris always anErrorobject, and thereforedata.erroris not always what the fetcher throws:https://github.com/solidjs/solid/blob/1afe035c80f0dc2815951e648e9fa4e8cc5e6054/packages/solid/src/reactive/signal.ts#L1687-L1690
If what the fetcher throws is a string, it becomes
data.error.message. If it's neither a string nor anError, it becomesdata.error.cause.I haven't found documentation for this and had to look at the code, but I think this is definitely something that should appear in the documentation.
Your Example Website or App
N/A
Steps to Reproduce the Bug or Issue
N/A
Expected behavior
The documentation of
createResource(and maybe other places where thecastErroris used) should mention the behavior.Screenshots or Videos
No response
Platform
All
Additional context
No response