NodeJs-assert断言例子

class : assert
- assert.fail(actual, expected, message, operator)
- assert(value, message), assert.ok(value, [message])
- assert.equal(actual, expected, [message])
- assert.notEqual(actual, expected, [message])
- assert.deepEqual(actual, expected, [message])
- assert.notDeepEqual(actual, expected, [message]) 
- assert.strictEqual(actual, expected, [message])
- assert.notStrictEqual(actual, expected, [message])
- assert.throws(block, [error], [message])
- assert.doesNotThrow(block, [message])
- assert.ifError(value)

console.log(assert);

/*

输出如下

{ [Function: ok]
AssertionError:
{ [Function: AssertionError]
super_:
{ [Function: Error]
captureStackTrace: [Function: captureStackTrace],
stackTraceLimit: 10 } },
fail: [Function: fail],
ok: [Circular],
equal: [Function: equal],
notEqual: [Function: notEqual],
deepEqual: [Function: deepEqual],
notDeepEqual: [Function: notDeepEqual],
strictEqual: [Function: strictEqual],
notStrictEqual: [Function: notStrictEqual],
throws: [Function],
doesNotThrow: [Function],
ifError: [Function] }
*/

assert是个函数，函数名为ok。javascript中函数是Function类的实例，也就是对象，所以可为其添加fail和equal等属性。注意输出结果第9行 ok:[Circular] 这个表述，这是指针循环的意思，即ok属性指向了本身，所以调用assert.ok就相当于调用了assert本身。