interim-not-cached (kind: required) asserts nothing

[mnot]

Problem

interim-not-cached is declared kind: 'required' but asserts nothing.

https://github.com/http-tests/cache-tests/blob/main/tests/interim.mjs#L58-L87

The cache-hit (second) request sets expected_interim_responses: []. The checker iterates that array:

https://github.com/http-tests/cache-tests/blob/main/test-engine/client/test.mjs#L199-L226

if ('expected_interim_responses' in reqConfig) {
  const isSetup = setupCheck(reqConfig, 'expected_interim_responses')
  reqConfig.expected_interim_responses.forEach(...)  // empty array => zero assertions
}

An empty array runs zero forEach iterations, so a cache that wrongly stored and replayed the 103 interim on the cache hit would still pass this required test.

Root cause

The framework only ever verifies that expected interim responses are present. There is no "assert no unexpected interim was received" path, so expected_interim_responses: [] cannot express the negative the test name requires.

Suggested fix

Add a negative check: when expected_interim_responses is present, also assert that no interim responses were received beyond those expected (i.e. interimResponses.length === reqConfig.expected_interim_responses.length). That makes the empty-array case meaningful and enforces interim-not-cached.

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Filed from an AI-assisted (Claude Code) review of the tests, with each finding verified by hand and reviewed by a human before filing.