unittest之測試用例名稱、收集規則

在unittest框架中，默認情況下，測試用例須以test開頭

但一定是需要以test_開頭嗎？

答案：不是

在unittest中，用例以什么開頭是可以自定義的，通過修改源碼的方法。

我們知道，用例的加載時unittest中的 test loader 實現的。
在loader.py模塊中，有一個TestLoader類。類中有一個testMethodPrefix的屬性，默認是test
當我們改成‘aaa’時，aaa開頭的測試用例將會被收集和裝載：

loader.py文件

class TestLoader(object):
    """
    This class is responsible for loading tests according to various criteria
    and returning them wrapped in a TestSuite
    """
    testMethodPrefix = 'aaa'
    sortTestMethodsUsing = staticmethod(util.three_way_cmp)
    testNamePatterns = None
    suiteClass = suite.TestSuite
    _top_level_dir = None

我們來寫一個aaa開頭的用例示例並執行：

test_prac1.py

import unittest


class TestPra1(unittest.TestCase):
    def setUp(self):
        print("this is setUp")

    def tearDown(self):
        print("this is tearDown")

    def aaa_1(self):
        self.assertEqual(2, 4)

test_prac2.py

import unittest


class TestPra2(unittest.TestCase):
    def setUp(self):
        print("this is setUp")

    def tearDown(self):
        print("this is tearDown")

    def aaa_2(self):
        self.assertEqual(2, 4)

執行結果如下：

this is setUp
this is tearDown
this is setUp
this is tearDown
FF
======================================================================
FAIL: aaa_1 (test_pra1.TestPra1)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "E:\unitPrac\test_pra1.py", line 16, in aaa_1
    self.assertEqual(2, 4)
AssertionError: 2 != 4

======================================================================
FAIL: aaa_2 (test_pra2.TestPra2)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "E:\unitPrac\test_pra2.py", line 17, in aaa_2
    self.assertEqual(2, 4)
AssertionError: 2 != 4

----------------------------------------------------------------------
Ran 2 tests in 0.000s

FAILED (failures=2)

Process finished with exit code 1

我們可以看到aaa_1和aaa_2都被執行了。
說明，收集用例的規則是可以通過loader模塊的TestLoader類中的類屬性testMethodPrefix來修改的。