[CURATOR-128] Enhance ZKPaths to be more lenient

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.7.0
• Component/s: Framework
• Assignee: Jordan Zimmerman
• Reporter: Scott Blum
• Created: 29/Jul/14 00:41
• Updated: 30/Jul/14 20:05
• Resolved: 30/Jul/14 17:24

Description

Add the following test to TestNamespaceFacade:

    @Test
    public void     testRootAccess() throws Exception
    {
        CuratorFramework    client = CuratorFrameworkFactory.newClient(server.getConnectString(), new RetryOneTime(1));
        try
        {
            client.start();

            client.create().forPath("/one");
            Assert.assertNotNull(client.getZookeeperClient().getZooKeeper().exists("/one", false));

            Assert.assertNotNull(client.checkExists().forPath("/"));
            try
            {
                client.checkExists().forPath("");
                Assert.fail("IllegalArgumentException expected");
            }
            catch ( IllegalArgumentException expected )
            {
            }

            Assert.assertNotNull(client.usingNamespace("one").checkExists().forPath(""));
            try
            {
                client.usingNamespace("one").checkExists().forPath("/");
                Assert.fail("IllegalArgumentException expected");
            }
            catch ( IllegalArgumentException expected )
            {
            }
        }
        finally
        {
            CloseableUtils.closeQuietly(client);
        }
    }

This tests PASSES, which means that there's no canonical way to refer to the root node. If the client is not namespaced, "/" works and "" does not work. If the client is namespaced, "" works and "/" does not.

In either case, I think ZKPaths.makePath mishandles certain cases.

If you append "/foo" and "/" the result is "/foo/" which is an invalid path.
On the other hand, if you append "" and "bar" the result is "//bar" which is also invalid.

What's the right behavior here? Does the root node / root of a namespace always need to be referred to as "/" or is empty string an acceptable alias?