Javascript 如何断言不为空？
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How to assert not null?
提问by Hosar
I'm very new in javascript testing, I would like to know how to assert not null in Mochaframework.
我在 javascript 测试方面很新，我想知道如何在Mocha框架中断言不为空。
回答by André Pena
Mocha supports any assertion library you want. You can take a look at how it deals with assertions here: http://mochajs.org/#assertions. I don't know which one you want to use.
Mocha 支持您想要的任何断言库。您可以在此处查看它如何处理断言：http: //mochajs.org/#assertions。不知道你想用哪一种。
Considering you are using Chai, which is pretty popular, here are some options:
考虑到您正在使用非常受欢迎的Chai，这里有一些选择：
Consider "foo" to be the target variable you want to test
将“foo”视为您要测试的目标变量
Assert
断言
var assert = chai.assert;
assert(foo) // will pass for any truthy value (!= null,!= undefined,!= '',!= 0)
// or
assert(foo != null)
// or
assert.notEqual(foo, null);
In case you want to use assert, you don't even need Chai. Just use it. Node supports it natively: https://nodejs.org/api/assert.html#assert_assert
如果您想使用assert，您甚至不需要 Chai。就用它。Node 本身支持它：https: //nodejs.org/api/assert.html#assert_assert
Should
应该
var should = require('chai').should();
should.exist(foo); // will pass for not null and not undefined
// or
should.not.equal(foo, null);
Expect
预计
var expect = chai.expect;
expect(foo).to.not.equal(null);
// or
expect(foo).to.not.be.null;
PS: Unrelated but on Jest there is a toBeNullfunction. You can do expect(foo).not.toBeNull();or expect(foo).not.toBe(null);
PS：无关但在 Jest 上有一个toBeNull功能。你可以做expect(foo).not.toBeNull();或expect(foo).not.toBe(null);
回答by kat
回答by FieryCat
In case, you're using Chai in addition to Mocha:
如果除了 Mocha 之外，您还使用 Chai：
assert.isNotNull(tea, 'great, time for tea!');
