[JBIDE-15830] ensure we return useragent from props even with empty

src/main/java/com/openshift/internal/client/RestServiceProperties.java

@@ -51,14 +51,14 @@ private String getStringProperty(String key) {
 		}
 	}
 
-	public String getUseragent(String id) {
+	public String getUseragent(String clientId) {
 		String userAgent = null;
 		String version = getVersion();
 		String useragentPattern = getUseragentPattern();
-		if (!StringUtils.isEmpty(id)
-				&& !StringUtils.isEmpty(version)
-				&& !StringUtils.isEmpty(useragentPattern)) {
-			userAgent = MessageFormat.format(useragentPattern, version, id);
+		if (!StringUtils.isEmpty(useragentPattern)) {
+			userAgent = MessageFormat.format(useragentPattern, 
+					StringUtils.nullToEmptyString(version), 
+					StringUtils.nullToEmptyString(clientId));
 		}
 		return userAgent;
 	}

src/main/java/com/openshift/internal/client/utils/StringUtils.java

@@ -43,4 +43,11 @@ public static String prependIfNonEmpty(String prefix, String string) {
 		return new StringBuilder(prefix).append(string).toString();
 	}
 
+	public static String nullToEmptyString(String string) {
+		if (string == null) {
+			return "";
+		}
+		return string;
+	}
+
 }

src/test/java/com/openshift/internal/client/RestServicePropertiesTest.java

@@ -55,4 +55,18 @@ public void shouldReturnClientIdAndVersion() {
 		String[] clientIdAndVersion = userAgent.split(" ");
 		assertThat(clientIdAndVersion).isNotNull().hasSize(2).containsOnly(clientId, VERSION);
 	}
+
+	@Test
+	public void shouldReturnUserAgentEvenIfClientIdIsNull() {
+		// pre-conditions
+
+		// operation
+		String userAgent = serviceProperties.getUseragent(null);
+
+		// verification
+		assertThat(userAgent).isNotEmpty();
+		// length of version + space, no client-id
+		assertThat(userAgent).hasSize(VERSION.length() + 1); 
+	}
+
 }