How does the interface automation framework httprunner generate dynamic classes

HttpRunner is a tool for automated testing of interfaces, which uses typefunctions in Python to generate dynamic classes.

In HttpRunner, test case classes are dynamically generated by using typefunctions and GenericTestCaseMetametaclasses.

Here is a sample code showing how to use typethe function to generate dynamic test case classes:

from httprunner import TestCase, HttpRunner

# 创建一个动态类的元类
class GenericTestCaseMeta(type):

    def __new__(cls, name, bases, attrs):
        # 动态为测试用例类添加属性和方法
        attrs['config'] = {}
        attrs['teststeps'] = []

        return super().__new__(cls, name, bases, attrs)

# 创建动态测试用例类
MyTestCase = type("MyTestCase", (TestCase,), {
    "__metaclass__": GenericTestCaseMeta
})

# 创建测试用例实例
tc = MyTestCase()

# 输出测试用例类的属性
print(tc.config)
print(tc.teststeps)

In this example, we define a metaclass to dynamically add and attributes to the class when creating the test case class GenericTestCaseMetaby overriding the method .__new__configteststeps

Then, we use typethe function to create a MyTestCasedynamic test case class called and pass it three parameters: the class name "MyTestCase", the base class , and a dictionary (TestCase,)containing metaclass information ."__metaclass__": GenericTestCaseMeta

Finally, we create an MyTestCaseinstance of the class tcand output the instance's configand teststepsproperties.

In this way, HttpRunner realizes the dynamic generation of test case classes, enabling users to customize the properties and methods of test case classes according to their needs.