test(server-test): enable run single unit test

[JisoLya]

Purpose of the PR

• close #xxx

Main Changes

Verifying these changes

• Trivial rework / code cleanup without any test coverage. (No Need)
• Already covered by existing tests, such as (please modify tests here).
• Need tests and can be verified as follows:
  • xxx

Does this PR potentially affect the following parts?

• Dependencies (add/update license info & regenerate_known_dependencies.sh)
• Modify configurations
• The public API
• Other affects (typed here)
• Nope

Documentation Status

• Doc - TODO
• Doc - Done
• Doc - No Need

[Copilot]

Pull request overview

This PR enables running individual unit tests from the CoreTestSuite without executing the entire test suite. Previously, running a single test class directly would fail because the graph initialization only occurred when running the full CoreTestSuite with JUnit's Suite runner.

Changes:

• Removed unused Assert import since Assert.assertNotNull(graph) assertion is no longer needed
• Modified graph() method to perform lazy initialization when graph is null, ensuring tests can run independently

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[imbajin]

‼️ Critical: Exception handling concern in lazy initialization

The initEnv() and init() methods can throw exceptions. If an exception occurs inside the synchronized block:

1. graph remains null
2. Subsequent calls will retry initialization (possibly desirable, but may cause repeated failures)

Consider whether failed initialization should be remembered to provide a clearer error message on subsequent calls, or at minimum document this behavior.

Also, there's an ordering dependency: initEnv() must complete before init(). While this works with the current registered flag, consider whether you need additional error handling if initEnv() succeeds but init() fails.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

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[Copilot]

The assignment graph = null is redundant here. At this point in the code flow, graph is guaranteed to be null because it's only assigned a value in the init() method at line 95. This redundant assignment has no effect and can be removed.