super.post() throws uncaught exception when POSTing to resource without trailing slash

[kriszyp]

When a Resource class exported by harper/redirects (or similar) is POSTed to without a trailing slash, super.post() throws an unhandled exception:

Cannot read properties of undefined (reading 'query')

With a trailing slash but a random path segment (e.g. /redirects/hi), the error changes slightly:

Cannot read properties of null (reading 'query')

Context

• Trailing slash IS required per design and this is documented — it's not a missing-feature issue.
• The problem is the unhandled exception surfacing to super.post() rather than a clean 404 or 405.
• Was silently working in 4.3; broke in 4.5 in a way that erodes confidence.

Ask

Catch the missing-trailing-slash case in the Resource request dispatch and return an appropriate HTTP error (404 or 405 with a clear message) rather than letting the Cannot read properties of undefined exception propagate.

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🤖 Filed by Claude on behalf of Kris.