fn update_for_tests()

in neqo-bin/src/client/mod.rs [227:302]

• 67 lines of code
• 9 McCabe index (conditional complexity)

    fn update_for_tests(&mut self) {
        let Some(testcase) = self.shared.qns_test.as_ref() else {
            return;
        };

        if self.key_update {
            qerror!("internal option key_update set by user");
            exit(127)
        }

        if self.resume {
            qerror!("internal option resume set by user");
            exit(127)
        }

        // Only use v1 for most QNS tests.
        self.shared.quic_parameters.quic_version = vec![Version::Version1];
        // This is the default for all tests except http3.
        self.shared.alpn = String::from("hq-interop");
        // Wireshark can't reassemble sliced CRYPTO frames, which causes tests to fail.
        // So let's turn that off by default, and only enable for some known-good QNS tests.
        self.shared.quic_parameters.no_sni_slicing = true;
        match testcase.as_str() {
            "http3" => {
                self.shared.quic_parameters.no_sni_slicing = false;
                self.shared.alpn = String::from("h3");
                if let Some(testcase) = &self.test {
                    if testcase.as_str() != "upload" {
                        qerror!("Unsupported test case: {testcase}");
                        exit(127)
                    }

                    self.method = String::from("POST");
                }
            }
            "handshake" | "transfer" | "retry" | "ecn" => {}
            "resumption" => {
                if self.urls.len() < 2 {
                    qerror!("Warning: resumption test won't work without >1 URL");
                    exit(127);
                }
                self.resume = true;
            }
            "zerortt" => {
                if self.urls.len() < 2 {
                    qerror!("Warning: zerortt test won't work without >1 URL");
                    exit(127);
                }
                self.shared.quic_parameters.no_sni_slicing = false;
                self.resume = true;
                // PMTUD probes inflate what we sent in 1-RTT, causing QNS to fail the test.
                self.shared.quic_parameters.no_pmtud = true;
                // If we pace, we might get the initial server flight before sending sufficient
                // 0-RTT data to pass the QNS check. So let's burst.
                self.shared.quic_parameters.no_pacing = true;
            }
            "multiconnect" => {
                self.download_in_series = true;
            }
            "chacha20" => {
                self.shared.ciphers.clear();
                self.shared
                    .ciphers
                    .extend_from_slice(&[String::from("TLS_CHACHA20_POLY1305_SHA256")]);
            }
            "keyupdate" => {
                self.key_update = true;
            }
            "v2" => {
                self.shared.quic_parameters.no_sni_slicing = false;
                // Use default version set for this test (which allows compatible vneg.)
                self.shared.quic_parameters.quic_version.clear();
            }
            _ => exit(127),
        }
    }