Bad assertion in testCallTool

[scottslewis]

In AbstractMcpSyncClientTests, there is a test case called {testCallTool](

java-sdk/mcp/src/test/java/io/modelcontextprotocol/client/AbstractMcpSyncClientTests.java

Line 238 in 110a8d1

void testCallTool() {

)

on line 247 is this assertion:

			assertThat(result.isError()).isNull();

Although currently satisfied by the 'everything server' (assertion passes with javascript server) this assumes that the result.isError() (a Boolean value) is null if there is no error. Since 'isError() is set to 'false' and not null on success (by java server at least) this line should probably be:

			assertThat(result.isError()).isFalse();

and that the everything server should be fixed to return isError=false rather than isError=null as it does currently.

[scottslewis]

This issue causes several of the failed tests in pr #439. The issue seems to be that the javascript mcp server sets isError to null rather than false, and so the assertions in the test cases above fail when used with the TestEverythingServer (java server test support), as the spec and impl of the IsError seems to prevent it being set to null, and sets it to 'false' rather than null as expected in the test cases.