test NXDOMAIN scenario

packages/conformance-tests/src/resolver/dns/scenarios.rs

@@ -60,3 +60,44 @@ fn can_resolve() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn nxdomain() -> Result<()> {
+    let needle_fqdn = FQDN("unicorn.nameservers.com.")?;
+
+    let mut root_ns = NameServer::new(FQDN::ROOT)?;
+    let mut com_ns = NameServer::new(FQDN::COM)?;
+
+    let mut nameservers_ns = NameServer::new(FQDN("nameservers.com.")?)?;
+    nameservers_ns
+        .a(root_ns.fqdn().clone(), root_ns.ipv4_addr())
+        .a(com_ns.fqdn().clone(), com_ns.ipv4_addr());
+    let nameservers_ns = nameservers_ns.start()?;
+
+    com_ns.referral(
+        nameservers_ns.zone().clone(),
+        nameservers_ns.fqdn().clone(),
+        nameservers_ns.ipv4_addr(),
+    );
+    let com_ns = com_ns.start()?;
+
+    root_ns.referral(FQDN::COM, com_ns.fqdn().clone(), com_ns.ipv4_addr());
+    let root_ns = root_ns.start()?;
+
+    let roots = &[Root::new(root_ns.fqdn().clone(), root_ns.ipv4_addr())];
+    let resolver = Resolver::start(dns_test::subject(), roots, &TrustAnchor::empty())?;
+    let resolver_ip_addr = resolver.ipv4_addr();
+
+    let client = Client::new()?;
+    let output = client.dig(
+        Recurse::Yes,
+        Dnssec::No,
+        resolver_ip_addr,
+        RecordType::A,
+        &needle_fqdn,
+    )?;
+
+    assert!(dbg!(output).status.is_nxdomain());
+
+    Ok(())
+}

packages/conformance-tests/src/resolver/dnssec/scenarios.rs

@@ -121,3 +121,6 @@ fn can_validate_with_delegation() -> Result<()> {
 
     Ok(())
 }
+
+// TODO nxdomain with NSEC records
+// TODO nxdomain with NSEC3 records

packages/dns-test/src/client.rs

@@ -220,13 +220,19 @@ pub enum DigStatus {
     NOERROR,
     NXDOMAIN,
     REFUSED,
+    SERVFAIL,
 }
 
 impl DigStatus {
     #[must_use]
     pub fn is_noerror(&self) -> bool {
         matches!(self, Self::NOERROR)
     }
+
+    #[must_use]
+    pub fn is_nxdomain(&self) -> bool {
+        matches!(self, Self::NXDOMAIN)
+    }
 }
 
 impl FromStr for DigStatus {
@@ -237,6 +243,7 @@ impl FromStr for DigStatus {
             "NXDOMAIN" => Self::NXDOMAIN,
             "NOERROR" => Self::NOERROR,
             "REFUSED" => Self::REFUSED,
+            "SERVFAIL" => Self::SERVFAIL,
             _ => return Err(format!("unknown status: {input}").into()),
         };