Add multiple features

crates/wtfnet-calc/src/lib.rs

@@ -200,3 +200,32 @@ fn overlap_v6(a: Ipv6Net, b: Ipv6Net) -> bool {
     let b_end = u128::from(b.broadcast());
     a_start <= b_end && b_start <= a_end
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn subnet_v4_from_mask() {
+        let info = subnet_info("192.168.1.10 255.255.255.0").expect("subnet");
+        assert_eq!(info.cidr, "192.168.1.10/24");
+        assert_eq!(info.network, "192.168.1.0");
+        assert_eq!(info.broadcast.as_deref(), Some("192.168.1.255"));
+        assert_eq!(info.usable_addresses, "254");
+    }
+
+    #[test]
+    fn contains_and_overlap() {
+        assert!(contains("192.168.0.0/16", "192.168.1.0/24").unwrap());
+        assert!(overlap("10.0.0.0/24", "10.0.0.128/25").unwrap());
+        assert!(!overlap("10.0.0.0/24", "10.0.1.0/24").unwrap());
+    }
+
+    #[test]
+    fn summarize_ipv4() {
+        let inputs = vec!["10.0.0.0/24".to_string(), "10.0.1.0/24".to_string()];
+        let result = summarize(&inputs).expect("summarize");
+        assert_eq!(result.len(), 1);
+        assert_eq!(result[0].to_string(), "10.0.0.0/23");
+    }
+}