python runtime_error ai_generated true

AssertionError: 1 != 2 : Test results depend on execution order

ID: python/unittest-testcase-ordering-issue

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
0Evidence
2025-03-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.8 active — — —
3.9 active — — —
3.10 active — — —
3.11 active — — —
3.12 active — — —

Root Cause

Tests share mutable state (e.g., a global variable or class attribute) without proper isolation, causing order-dependent failures.

generic

中文

测试共享可变状态（例如全局变量或类属性）而没有适当的隔离，导致顺序依赖的失败。

Workarounds

  1. 95% success 
    Use setUp() to initialize fresh state for each test: `def setUp(self): self.shared_var = 0`
  2. 90% success 
    Refactor tests to avoid shared state by using local variables or mocks.

Dead Ends

Common approaches that don't work:

  1. 90% fail

    This is a brittle workaround; any change in test discovery order can break tests again.

  2. 80% fail

    setUpClass runs once per class, not per test, so state can still leak between tests.