tests: rework the actually useful tests to live in the integration crate

crates/irtt-client/tests/client/config.rs

@@ -0,0 +1,117 @@
+use super::*;
+
+#[test]
+fn connect_rejects_invalid_configuration() {
+    let i64_max_ns = u64::try_from(i64::MAX).unwrap();
+    let too_large = Duration::from_nanos(i64_max_ns) + Duration::from_nanos(1);
+    let cases = [
+        (
+            "oversized UDP payload",
+            ClientConfig {
+                length: MAX_UDP_PAYLOAD_LENGTH + 1,
+                ..ClientConfig::default()
+            },
+            "packet length",
+        ),
+        (
+            "zero finite duration",
+            ClientConfig {
+                duration: Some(Duration::ZERO),
+                ..ClientConfig::default()
+            },
+            "duration must be greater than zero; use None for continuous mode",
+        ),
+        (
+            "zero interval",
+            ClientConfig {
+                interval: Duration::ZERO,
+                ..ClientConfig::default()
+            },
+            "interval must be greater than zero",
+        ),
+        (
+            "duration nanosecond overflow",
+            ClientConfig {
+                duration: Some(too_large),
+                ..ClientConfig::default()
+            },
+            "duration is too large to encode as nanoseconds",
+        ),
+        (
+            "interval nanosecond overflow",
+            ClientConfig {
+                interval: too_large,
+                ..ClientConfig::default()
+            },
+            "interval is too large to encode as nanoseconds",
+        ),
+        (
+            "invalid DSCP codepoint",
+            ClientConfig {
+                dscp: 64,
+                ..ClientConfig::default()
+            },
+            "dscp",
+        ),
+        (
+            // The unspecified clock is the absent-tag wire default, not a
+            // client mode; a client that needs timestamps must name a clock.
+            "unspecified clock",
+            ClientConfig {
+                clock: Clock::Unspecified,
+                ..ClientConfig::default()
+            },
+            "clock must be wall, monotonic, or both",
+        ),
+        (
+            "empty server fill",
+            ClientConfig {
+                server_fill: Some("".to_owned()),
+                ..ClientConfig::default()
+            },
+            "server_fill",
+        ),
+        (
+            "oversized server fill",
+            ClientConfig {
+                server_fill: Some("0123456789abcdef0123456789abcdefx".to_owned()),
+                ..ClientConfig::default()
+            },
+            "server_fill",
+        ),
+    ];
+
+    for (name, config, expected_reason) in cases {
+        assert!(
+            matches!(
+                Client::connect(config),
+                Err(ClientError::InvalidConfig { .. })
+            ),
+            "{name} should fail with InvalidConfig ({expected_reason})"
+        );
+    }
+}
+
+#[test]
+fn minimum_open_timeout_under_200ms_is_rejected() {
+    let config = ClientConfig {
+        open_timeouts: vec![Duration::from_millis(199)],
+        ..ClientConfig::default()
+    };
+    assert!(matches!(
+        Client::connect(config),
+        Err(ClientError::OpenTimeoutTooSmall { .. })
+    ));
+}
+
+#[test]
+fn empty_open_timeouts_is_rejected() {
+    let config = ClientConfig {
+        open_timeouts: vec![],
+        ..ClientConfig::default()
+    };
+    assert!(matches!(
+        Client::connect(config),
+        Err(ClientError::NoOpenTimeouts)
+    ));
+}