TypeError in SSEClient#close from paren-less is_a? call (8.11.0)

[dan98765]

Description

Version 8.11.0 introduced a TypeError: class or module required in SSEClient#close that fires on every SSE socket close. The error is caught by the rescue StandardError block so it doesn't crash the process, but it generates a high volume of error log entries (~400/day in our production environment across multiple services consuming the SDK).

We had to pin splitclient-rb < 8.11.0 in our wrapper gem to avoid this.

SDK Version

• Affected: 8.11.0, master
• Not affected: 8.10.1 and earlier

Root Cause

In lib/splitclient-rb/sse/event_source/client.rb, line 50 of the close method:

@config.logger.debug("SSEClient socket state #{@socket.state}") if @socket.is_a? OpenSSL::SSL::SSLSocket && @config.debug_enabled

Without explicit parentheses, Ruby parses the is_a? argument as:

@socket.is_a?(OpenSSL::SSL::SSLSocket && @config.debug_enabled)

Since OpenSSL::SSL::SSLSocket is truthy, && evaluates and returns the right operand (@config.debug_enabled, a boolean). Then is_a?(true) or is_a?(false) raises TypeError: class or module required.

Note that line 48 has a similar is_a? call but without &&, so it parses correctly:

@socket.sync_close = true if @socket.is_a? OpenSSL::SSL::SSLSocket  # works fine

Suggested Fix

Add explicit parentheses:

@config.logger.debug("SSEClient socket state #{@socket.state}") if @socket.is_a?(OpenSSL::SSL::SSLSocket) && @config.debug_enabled

Happy to submit a PR for this if that's helpful.