[sujal-maheshwari2004]

What was wrong

priompt/priompt#33 changes the server's URI-to-subject mapping (internal/pubsub.Subject). Each URI segment becomes one subject token, and every byte outside [A-Za-z0-9_-] is percent-encoded with uppercase hex:

priompt://acme/support/agent  ->  priompt.acme.support.agent       (unchanged)
priompt://acme.corp/x/a.b     ->  priompt.acme%2Ecorp.x.a%2Eb

subject() in client.js still replaced / with . and left segment contents as they were. So against that server, subscribe() on a URI with a dot (or any other encoded byte) in a segment listened on a subject that never receives events.

Fix

subject() now does the same thing as the server's Subject/subjectToken. It strips the priompt:// prefix, splits on /, and percent-encodes each segment per UTF-8 byte (Go's loop works on bytes too), using uppercase two-digit hex. Dot-free URIs keep their subject, so nothing changes against current servers for them.

subject is now exported next to PromptClient so the tests can call it.

Test evidence

test/subject.test.js reuses the server's cases from TestSubjectIsInjective/TestSubjectMapping: the three collision pairs, agent-v2_x, priompt://acme.corp/x/a.b, and a non-ASCII segment.

Before the fix (main):

✖ distinct URIs map to distinct subjects        actual: 'priompt.acme.a.b'
✔ dot-free URIs keep their subject
✖ bytes outside [A-Za-z0-9_-] are percent-encoded with uppercase hex   actual: 'priompt.acme.corp.x.a.b'
ℹ pass 1
ℹ fail 2

After:

$ npm test
✔ distinct URIs map to distinct subjects
✔ dot-free URIs keep their subject
✔ bytes outside [A-Za-z0-9_-] are percent-encoded with uppercase hex
ℹ pass 3
ℹ fail 0

Cross-check against the server's own Go Subject() on the #33 branch (91eb76b): JS output equals Go output for 10 URIs (the collision pairs plus acme/café → priompt.acme.caf%C3%A9 and acme/a b/~x → priompt.acme.a%20b.%7Ex).

Real run with a server built from priompt/priompt#33, on priompt://acme/support/agent.v2 (subscribe, then publish over gRPC):

== main
published priompt://acme/support/agent.v2 5d27c91cdca3
no event within 3s
== this branch
published priompt://acme/support/agent.v2 43d6742cc6a6
event 43d6742cc6a6 "structural"

Notes

• Ship this with, or after, fix: encode URI segments in NATS subjects so the mapping is exact priompt#33. Against an older server, dotted URIs need the old mapping. Dot-free URIs work with both.
• A trial merge with each of fix: replace deprecated nats package with @nats-io/transport-node #9, fix: surface the broker's Authorization Violation from subscribe() #10 and fix: read PRIOMPT_TOKEN and re-sync the vendored proto #11 is clean. They add the same npm test script and CI line.

Fixes #12

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