Leaked socket in cache/internal/cacheHttpClient

[mweberxyz]

actions/cache#1217 attempted to work around a dangling socket, which became especially apparent when that action migrated to Node 20, as Node v20 started keeping connection alive by default.

This solution worked for actions/cache in the meantime, but caused downstream consumers of to implement the same logic to avoid hanging processes and generated similar issues, such as:

• @actions/ccache causing 2min slowdown with Node 20 runtime #1643
• Fix performance regression masci/datadog#33

The leaked socket originates in cache/src/internal/cacheHttpClient:

  const uploadChunkResponse = await retryHttpClientResponse(
    `uploadChunk (start: ${start}, end: ${end})`,
    async () =>
      httpClient.sendStream(
        'PATCH',
        resourceUrl,
        openStream(),
        additionalHeaders
      )
  )

sendStream return a response, the body of must be consumed to avoid holding the event loop open.

Something like the following ought to do it:

  const uploadChunkResponse = await retryHttpClientResponse(
    `uploadChunk (start: ${start}, end: ${end})`,
    async () => {
      const response = await httpClient.sendStream(
        'PATCH',
        resourceUrl,
        openStream(),
        additionalHeaders
      )

      await response.readBody()

      return response
    }
  )