Node.js 中的 assert.doesNotThrow() 函数
node.jsjavascriptweb developmentfront end technology
assert 模块提供了一系列用于函数断言的不同功能。assert.doesNotThrow 将断言该函数无法抛出错误。当调用 assert.doesNotThrow 时，它将立即调用 'fn'。
语法
assert.doesNotThrow(fn, [error], [message])
参数
上述参数描述如下 −
fn – 执行 assert.doesNotThrow 时将调用此函数。它将调用此函数而不是抛出错误。
error ——此参数包含指定错误的正则表达式。它是一个可选参数。
message ——这是一个可选参数。这是执行函数时打印的用户定义消息。
安装 Assert 模块
npm install assert
assert 模块是一个内置的 Node.js 模块，因此您也可以跳过此步骤。您可以使用以下命令检查断言版本以获取最新的断言模块。
npm version assert
在您的函数中导入模块
const assert = require("assert").strict;
示例
创建一个名为 – doesNotThrow.js 的文件并复制以下代码片段。创建文件后，使用以下命令运行此代码。
node doesNotThrow.js
doesNotThrow.js
// 导入模块
const assert = require('assert').strict;
try {
// Calling the doesNotThrow method to stop throwing error
assert.doesNotThrow(
() => {
throw new TypeError('Wrong value received. Please check !');
},
);
} catch(error) {
console.log("Error:", error)
}
输出
C:\home
ode>> node doesNotThrow.js Error: { AssertionError [ERR_ASSERTION]: Got unwanted exception. Actual message: "Wrong value received. Please check !" at Object. (/home/node/test/assert.js:6:9) at Module._compile (internal/modules/cjs/loader.js:778:30) at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10) at Module.load (internal/modules/cjs/loader.js:653:32) at tryModuleLoad (internal/modules/cjs/loader.js:593:12) at Function.Module._load (internal/modules/cjs/loader.js:585:3) at Function.Module.runMain (internal/modules/cjs/loader.js:831:12) at startup (internal/bootstrap/node.js:283:19) at bootstrapNodeJSCore (internal/bootstrap/node.js:623:3) generatedMessage: false, name: 'AssertionError [ERR_ASSERTION]', code: 'ERR_ASSERTION', actual: TypeError: Wrong value received. Please check ! at assert.doesNotThrow (/home/node/test/assert.js:8:9) at getActual (assert.js:567:5) at Function.doesNotThrow (assert.js:687:32) at Object. (/home/node/test/assert.js:6:9) at Module._compile (internal/modules/cjs/loader.js:778:30) at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10) at Module.load (internal/modules/cjs/loader.js:653:32) at tryModuleLoad (internal/modules/cjs/loader.js:593:12) at Function.Module._load (internal/modules/cjs/loader.js:585:3) at Function.Module.runMain (internal/modules/cjs/loader.js:831:12), expected: undefined, operator: 'doesNotThrow' }
示例
我们再看一个例子。
// 导入模块
const assert = require('assert').strict;
try {
assert.doesNotThrow(
() => {
throw new TypeError('Value passed is wrong !!');
},
/abcd/,
'Whoops'
);
} catch(error) {
console.log("Error:", error)
}
输出
C:\home
ode>> node doesNotThrow.js Error: TypeError: Value passed is wrong !! at assert.doesNotThrow (/home/node/test/assert.js:7:9) at getActual (assert.js:567:5) at Function.doesNotThrow (assert.js:687:32) at Object. (/home/node/test/assert.js:5:9) at Module._compile (internal/modules/cjs/loader.js:778:30) at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10) at Module.load (internal/modules/cjs/loader.js:653:32) at tryModuleLoad (internal/modules/cjs/loader.js:593:12) at Function.Module._load (internal/modules/cjs/loader.js:585:3) at Function.Module.runMain (internal/modules/cjs/loader.js:831:12)
