[Bug]: Invalid ALPN protocol identifier in https-proxy-agent

[kherock]

Version

1.55.0

Steps to reproduce

1. Create a Playwright project with use.proxy.server set to an HTTPS server. I am using a project called dumbproxy in this case
2. Create a test that uses the request fixture to make a request to an external service (e.g. github.com)
3. Observe that the ALPN protocol is set to an invalid value of http 1.1
   

Expected behavior

The TLS handshake for proxied requests should have the ALPN protocol set to the standard value for HTTP/1.1, which is http/1.1.

Actual behavior

If the forward proxy does not implement fallback behavior for the invalid ALPN protocol value, an SSL exception is raised. In my case I get the following error:

    [cause]: Error: apiRequestContext.fetch: write EPROTO 40A1E5F501000000:error:0A000460:SSL routines:ssl3_read_bytes:tlsv1 alert no application protocol:ssl/record/rec_layer_s3.c:911:SSL alert number 120

Additional context

This bug was raised and resolved in version 6.0.0 of https-proxy-agent:
TooTallNate/proxy-agents#142

The latest version is now 7.0.6.

Environment

System:
    OS: macOS 15.7.1
    CPU: (10) arm64 Apple M1 Pro
    Memory: 69.27 MB / 16.00 GB
  Binaries:
    Node: 20.19.3 - /opt/homebrew/bin/node
    npm: 10.8.2 - /opt/homebrew/bin/npm
    pnpm: 10.14.0 - /opt/homebrew/bin/pnpm
  IDEs:
    VSCode: 1.104.2 - /usr/local/bin/code
  Languages:
    Bash: 3.2.57 - /bin/bash
  npmPackages:
    @playwright/test: ^1.55.0 => 1.55.0

[Skn0tt]

Thanks for the issue and looking into the root cause. I'll try bumping the version - last time we tried to, it regressed some customers, so I'm expecting this to be a little more complex. See #34535