[divybot]

Summary

Enables test-http2-empty-frame-without-eof in node_compat suite.

Test plan

• cargo test --test node_compat -- test-http2-empty-frame-without-eof

[fibibot]

LGTM. Walked through the substance:

1. Empty DATA frame detection in on_frame_recv_callback: when frame_header_length(frame) == 0 and END_STREAM is unset, increment invalid_frame_count and trip if it exceeds max_invalid_frames. nghttp2 itself doesn't flag empty-DATA-without-EOF as a protocol error, so the JS layer needs to count it — same as Node's HandleDataFrame in src/node_http2.cc.

2. Post-increment comparison corrected in on_invalid_frame_recv_callback: changed from count >= session.max_invalid_frames (with a > 0 guard that disabled max=0) to count > session.max_invalid_frames, matching Node's if (invalid_frame_count_++ > max_invalid_frames). The semantics now line up exactly:

   • max=0: 1 invalid frame allowed (count=0, check 0 > 0 false), 2nd trips (count=1, 1 > 0 true).
   • max=2: 2 allowed, 3rd trips.
   • That's exactly what the upstream test exercises (max=0 → must error with "Too many invalid HTTP/2 frames"; max=2 → must not error).

3. custom_recv_error_code plumbing: nghttp2 callbacks set Some("ERR_HTTP2_TOO_MANY_INVALID_FRAMES"), then receive_data checks the return value of nghttp2_session_mem_recv — if negative (fatal), emit_session_internal_error(ret) builds a v8 scope and invokes session_internal_error_cb(integerCode, customErrorCode). Mirrors Node's Http2Session::custom_recv_error_code_ exactly. ✓

4. emit_session_internal_error uses the same v8-scope pattern (from_raw_isolate_ptr → ContextScope → callback.call) as the existing invoke_session_internal_error helper. The custom code is take()n out of the field so subsequent emits don't re-emit it. Note this has 2 args (errno, customErrorCode) where the existing invoke_session_internal_error has 1 (errno only) — that's intentional, since this is the path that needs to surface the custom code to JS.

5. JS-side kCustomErrorMessages map translates ERR_HTTP2_TOO_MANY_INVALID_FRAMES to "Too many invalid HTTP/2 frames". __proto__: null prevents pollution. Falls back to the code string if unknown. Matches the test's expectsError({code: 'ERR_HTTP2_TOO_MANY_INVALID_FRAMES', message: 'Too many invalid HTTP/2 frames'}). ✓

6. saturating_add on invalid_frame_count: u32 defends against overflow at the cost of saturating at u32::MAX. Reasonable — by the time you've received 4B invalid frames, the session is well past the limit.

Test enrollment alphabetically positioned (dont-override < empty-frame-without-eof < endafterheaders). ✓

CI fully green: 133 SUCCESS, 0 FAILURE, 2 SKIPPED. All 36 test node_compat shards × all 12 test unit_node shards × all 24 test specs shards green.