HTTPFetcher drops HTTP 304 responses needed by yr provider cache handling

[sonnyb9]

Summary

In MagicMirror v2.35.0, the yr weather provider has explicit logic to handle 304 Not Modified responses and reuse cached data, but js/http_fetcher.js still routes all non-OK responses into the error path.

That means a 304 response never reaches defaultmodules/weather/providers/yr.js, even though the provider is written to handle it.

Affected Version

• Confirmed locally on v2.35.0 (d05ea751)

Evidence

Provider expects 304

defaultmodules/weather/providers/yr.js contains logic like:

action on response:
if (response.status === 304) {
  use cached data
  return
}

Core fetcher blocks 304

Unpatched js/http_fetcher.js in v2.35.0 currently behaves like:

if (!response.ok) {
  this.emit("error", errorInfo)
} else {
  this.emit("response", response)
}

Since response.ok is false for HTTP 304, the response is treated as an error instead of being emitted to the provider.

Why This Matters

• yr sends cache-aware responses.
• The provider already contains 304 reuse logic.
• The core fetcher prevents that logic from running.
• Result: 304 Not Modified behaves like an error instead of a cache hit.

Minimal Fix

Allow 304 to flow through the normal response event so cache-aware providers can decide what to do:

if (response.status === 304) {
  this.emit("response", response)
} else if (!response.ok) {
  const { delay, errorInfo } = this.#getDelayForResponse(response)
  nextDelay = delay
  this.emit("error", errorInfo)
} else {
  this.emit("response", response)
}

Expected Behavior

When the upstream server returns 304 Not Modified, providers that are built to reuse cached data should receive that response and handle it themselves.

Actual Behavior

HTTPFetcher classifies 304 as an error before the provider sees it.

Local Impact

This was observed while using the built-in weather yr provider with cache headers and existing cached weather data. The local workaround is a small patch to js/http_fetcher.js that lets 304 responses reach the provider.