Don't validate RDAP nameserver names using validateDomainName

The nameserver may be external, in which case its TLD will not appear in our
list of valid TLDs, and the search will be rejected erroneously.

Tests for letter case canonicalizations also added at reviewer's suggestion.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=171985702

javatests/google/registry/rdap/RdapDomainActionTest.java

@@ -15,7 +15,6 @@
 package google.registry.rdap;
 
 import static com.google.common.truth.Truth.assertThat;
-import static com.google.common.truth.Truth8.assertThat;
 import static google.registry.testing.DatastoreHelper.createTld;
 import static google.registry.testing.DatastoreHelper.persistResource;
 import static google.registry.testing.DatastoreHelper.persistSimpleResources;
@@ -322,21 +321,44 @@ public class RdapDomainActionTest {
     }
   }
 
+  private void assertProperResponseForCatLol(String queryString, String expectedOutputFile) {
+    assertJsonEqual(
+        generateActualJson(queryString),
+        generateExpectedJsonWithTopLevelEntries(
+            "cat.lol",
+            null,
+            "C-LOL",
+            expectedOutputFile.equals("rdap_domain.json")
+                ? ImmutableList.of("4-ROID", "6-ROID", "2-ROID")
+                : null,
+            expectedOutputFile));
+    assertThat(response.getStatus()).isEqualTo(200);
+  }
+
   @Test
   public void testInvalidDomain_returns400() throws Exception {
     assertJsonEqual(
         generateActualJson("invalid/domain/name"),
         generateExpectedJson(
-            "invalid/domain/name is not a valid domain name", null, "1", "rdap_error_400.json"));
+            "invalid/domain/name is not a valid domain name: Domain names can only contain a-z,"
+                + " 0-9, '.' and '-'",
+            null,
+            "1",
+            "rdap_error_400.json"));
     assertThat(response.getStatus()).isEqualTo(400);
   }
 
   @Test
-  public void testUnknownDomain_returns404() throws Exception {
+  public void testUnknownDomain_returns400() throws Exception {
     assertJsonEqual(
         generateActualJson("missingdomain.com"),
-        generateExpectedJson("missingdomain.com not found", null, "1", "rdap_error_404.json"));
-    assertThat(response.getStatus()).isEqualTo(404);
+        generateExpectedJson(
+            "missingdomain.com is not a valid domain name: Domain name is under tld com which"
+                + " doesn't exist",
+            null,
+            "1",
+            "rdap_error_400.json"));
+    assertThat(response.getStatus()).isEqualTo(400);
   }
 
   @Test
@@ -349,15 +371,7 @@ public class RdapDomainActionTest {
 
   @Test
   public void testValidDomain_works() throws Exception {
-    assertJsonEqual(
-        generateActualJson("cat.lol"),
-        generateExpectedJsonWithTopLevelEntries(
-            "cat.lol",
-            null,
-            "C-LOL",
-            ImmutableList.of("4-ROID", "6-ROID", "2-ROID"),
-            "rdap_domain.json"));
-    assertThat(response.getStatus()).isEqualTo(200);
+    assertProperResponseForCatLol("cat.lol", "rdap_domain.json");
   }
 
   @Test
@@ -366,69 +380,34 @@ public class RdapDomainActionTest {
     action.authResult = AuthResult.create(AuthLevel.USER, adminUserAuthInfo);
     when(sessionUtils.checkRegistrarConsoleLogin(request, adminUserAuthInfo)).thenReturn(false);
     when(sessionUtils.getRegistrarClientId(request)).thenReturn("noregistrar");
-    assertJsonEqual(
-        generateActualJson("cat.lol"),
-        generateExpectedJsonWithTopLevelEntries(
-            "cat.lol",
-            null,
-            "C-LOL",
-            ImmutableList.of("4-ROID", "6-ROID", "2-ROID"),
-            "rdap_domain.json"));
-    assertThat(response.getStatus()).isEqualTo(200);
+    assertProperResponseForCatLol("cat.lol", "rdap_domain.json");
   }
 
   @Test
   public void testValidDomain_notLoggedIn_noContacts() throws Exception {
     when(sessionUtils.checkRegistrarConsoleLogin(request, userAuthInfo)).thenReturn(false);
-    assertJsonEqual(
-        generateActualJson("cat.lol"),
-        generateExpectedJsonWithTopLevelEntries(
-            "cat.lol",
-            null,
-            "C-LOL",
-            null,
-            "rdap_domain_no_contacts.json"));
-    assertThat(response.getStatus()).isEqualTo(200);
+    assertProperResponseForCatLol("cat.lol", "rdap_domain_no_contacts.json");
   }
 
   @Test
   public void testValidDomain_loggedInAsOtherRegistrar_noContacts() throws Exception {
     when(sessionUtils.getRegistrarClientId(request)).thenReturn("otherregistrar");
-    assertJsonEqual(
-        generateActualJson("cat.lol"),
-        generateExpectedJsonWithTopLevelEntries(
-            "cat.lol",
-            null,
-            "C-LOL",
-            null,
-            "rdap_domain_no_contacts.json"));
-    assertThat(response.getStatus()).isEqualTo(200);
+    assertProperResponseForCatLol("cat.lol", "rdap_domain_no_contacts.json");
+  }
+
+  @Test
+  public void testUpperCase_ignored() throws Exception {
+    assertProperResponseForCatLol("CaT.lOl", "rdap_domain.json");
   }
 
   @Test
   public void testTrailingDot_ignored() throws Exception {
-    assertJsonEqual(
-        generateActualJson("cat.lol."),
-        generateExpectedJsonWithTopLevelEntries(
-            "cat.lol",
-            null,
-            "C-LOL",
-            ImmutableList.of("4-ROID", "6-ROID", "2-ROID"),
-            "rdap_domain.json"));
-    assertThat(response.getStatus()).isEqualTo(200);
+    assertProperResponseForCatLol("cat.lol.", "rdap_domain.json");
   }
 
   @Test
   public void testQueryParameter_ignored() throws Exception {
-    assertJsonEqual(
-        generateActualJson("cat.lol?key=value"),
-        generateExpectedJsonWithTopLevelEntries(
-            "cat.lol",
-            null,
-            "C-LOL",
-            ImmutableList.of("4-ROID", "6-ROID", "2-ROID"),
-            "rdap_domain.json"));
-    assertThat(response.getStatus()).isEqualTo(200);
+    assertProperResponseForCatLol("cat.lol?key=value", "rdap_domain.json");
   }
 
   @Test