学习笔记-断言

1. 元素是否存在

find_elements

2. 元素属性是否正确

get_attribute
assert 'xxxx' in element.get_attribute('resource-id')

3. 查找元素文本

assert float(find_element_by_id('xxxx).text)>20

4. hamcrest断言

• Hamcrest是用于Java的单元测试的框架，它使用matcher匹配器来进行断言。在Spring-boot-starter中集成了Hamcrest,无需而外引入。
  [https://github.com/hamcrest/PyHamcrest](https://github.com/hamcrest/PyHamcrest)

安装
pip install PyHamcrest

• IS

String str1 = "text";
String str2 = " text ";
assertThat(str1, is(equalToIgnoringWhiteSpace(str2)));
String str1 = "text";
String str2 = "text";
assertThat(str1, is(str2));

• NOT

String str1 = "text";
String str2 = " text ";
assertThat(str1, not(equalToIgnoringWhiteSpace(str2)));

String str1 = "text";
String str2 = "text";
assertThat(str1, not(str2));

• containsString

String str1 = "text123";
String str2 = "text";
assertThat(str1, containsString(str2));

• 以为某个字段开头/结尾

String str1 = "text123";
assertThat(str1, startsWith("text"));// 以某个字符开头
assertThat(str1, endsWith("text"));// 以某个字符开头

• 判断两个对象是否为同一个实体

Cat cat=new Cat();
assertThat(cat, sameInstance(cat));

• 类似OR的效果

String str = "calligraphy";
String start = "call";
String end = "foo";
assertThat(str, anyOf(startsWith(start), containsString(end)));

• 类似AND的效果

String str = "calligraphy";
String start = "call";
String end = "phy";
assertThat(str, allOf(startsWith(start), endsWith(end)));

• Number 匹配器

assertThat(1, greaterThan(0)); // 大于
assertThat(5, greaterThanOrEqualTo(5)); //大于等于
assertThat(-1, lessThan(0)); // 小于
assertThat(-1, lessThanOrEqualTo(5)); // 小于等于

• Text 匹配器

String str = "";
assertThat(str, isEmptyString()); // 空字符串
assertThat(str, isEmptyOrNullString()); // 空字符串或者null

• 匹配字符串相等

String str1 = "text";
String str2 = " text ";
assertThat(str1, equalToIgnoringWhiteSpace(str2)); // 忽略左右空白
assertThat(a, equalToIgnoringCase(b)); //忽略大小写

• Collections 匹配器

• 检查某个元素是否在集合中

List<String> collection = Lists.newArrayList("ab","cd","ef");
assertThat(collection, hasItem("cd"));
assertThat(collection, not(hasItem("zz")));
assertThat(collection, hasItems("cd", "ab")); // 检查多个元素是否在集合中

• 检查所有元素

List<String> collection = Lists.newArrayList("ab","cd","ef");
assertThat(collection, hasItems("ab","cd","ef"));
assertThat(collection, hasItems("cd", "ab","ef")); // 错误
assertThat(collection, hasItems("ab","cd")); // 错误
assertThat(collection, containsInAnyOrder("cd", "ab","ef")); //正确,不区分顺序

• 集合为空检查

List<String> collection = Lists.newArrayList("ab","cd","ef");
assertThat(collection, empty()); // false, 用于检查集合类型

• 数组为空检查

String[] array = new String[] { "ab" };
assertThat(array, emptyArray()); // false

5. 总结

核心：
    anything - 总是匹配,如果你不关心测试下的对象是什么是有用的
    describedAs - 添加一个定制的失败表述装饰器
    is - 改进可读性装饰器 - 见下 “Sugar”
逻辑：
    allOf - 如果所有匹配器都匹配才匹配,像Java里的&&
    anyOf - 如果任何匹配器匹配就匹配,像Java里的||
    not - 如果包装的匹配器不匹配器时匹配,反之亦然
对象：
    equalTo - 测试对象相等使用Object.equals方法
    hasToString - 测试Object.toString方法
    instanceOf, isCompatibleType - 测试类型
    notNullValue, nullValue - 测试null
    sameInstance - 测试对象实例
Beans：
    hasProperty - 测试JavaBeans属性
集合：
    array - 测试一个数组元素test an array’s elements against an array of matchers
    hasEntry, hasKey, hasValue - 测试一个Map包含一个实体,键或者值
    hasItem, hasItems - 测试一个集合包含一个元素
    hasItemInArray - 测试一个数组包含一个元素
数字：
    closeTo - 测试浮点值接近给定的值
    greaterThan, greaterThanOrEqualTo, lessThan, lessThanOrEqualTo - 测试次序
文本：
    equalToIgnoringCase - 测试字符串相等忽略大小写
    equalToIgnoringWhiteSpace - 测试字符串忽略空白
    containsString, endsWith, startsWith - 测试字符串匹配