Updated channel validation exception messages

Author: rcameronm

src/main/java/emissary/grpc/channel/ChannelManager.java

@@ -95,14 +95,16 @@ protected String validateHostName(String host) {
         if (host.equals(LOCALHOST) || host.startsWith(DNS_PREFIX)) {
             return host;
         }
-        throw new IllegalArgumentException(String.format("Expected DNS URI prefix \"dns:///\" but got \"%s\"", host));
+        throw new IllegalArgumentException(
+                String.format("Expected \"%s\" or DNS URI prefix \"%s\" but got \"%s\"", LOCALHOST, DNS_PREFIX, host));
     }
 
     protected int validatePortNumber(int port) {
         if (port > 0 && port <= MAX_PORT_NUMBER) {
             return port;
         }
-        throw new IllegalArgumentException(String.format("Port \"%d\" is outside valid range [1, %d]", port, MAX_PORT_NUMBER));
+        throw new IllegalArgumentException(
+                String.format("Port \"%d\" is outside valid range [1, %d]", port, MAX_PORT_NUMBER));
     }
 
     protected String createTarget(String host, int port) {

src/test/java/emissary/grpc/channel/ChannelManagerTest.java

@@ -25,7 +25,7 @@ void testGoodHostName(String host) {
     void testBadHostName(String host) {
         Runnable invocation = () -> new TestChannelManager(host, 1).close();
         IllegalArgumentException e = assertThrows(IllegalArgumentException.class, invocation::run);
-        assertEquals(String.format("Expected DNS URI prefix \"dns:///\" but got \"%s\"", host), e.getMessage());
+        assertEquals(String.format("Expected \"localhost\" or DNS URI prefix \"dns:///\" but got \"%s\"", host), e.getMessage());
     }
 
     @ParameterizedTest