在我们的mocha测试中,有时我们有bug和抛出异常,当这些异常被抛出时,后续的断言不会被调用,我们的测试可能会通过,即使有一些错误。
// this would pass
it('adsf', async () => {
assert.equal(1,1)
var foo = undefined;
foo.hi(); // throw exception
assert.equal(1,2) // assert not called
});
我们尝试将其包装在try catch中,如下所示
// this would fail, but not say why
it('adsf', async () => {
try {
assert.equal(1,1)
// var foo = undefined;
// foo.hi();
assert.equal(1,2)
} catch (err) {
assert.fail(err) // if fail, such as the 1,2 case above, the line number of the error is not shown
}
});
但是catch
案例隐藏了一些失败的断言信息。如果任何人有任何建议,将不胜感激。
发布于 2019-06-26 11:01:36
您示例中的测试将不会通过。在mocha中,如果在测试中调用的函数抛出异常,则测试将失败。示例:
const assert = require('assert');
function foo() {
throw new Error('err');
}
describe('test', () => {
it('works', async () => {
foo();
console.log('came here');
});
});
$ npx mocha test.js
test
1) works
0 passing (6ms)
1 failing
1) test
works:
Error: err
at foo (test.js:8:9)
at Context.<anonymous> (test.js:13:11)
at processImmediate (internal/timers.js:439:21)
因此,在您的示例中,由于foo.hi
抛出了TypeError
,因此它将被mocha捕获并显示为测试失败(执行实际上不会到达asserts,但无论如何测试都会显示为失败)。
我怀疑在你的案例中会发生的是抛出一个承诺或拒绝一个承诺,就像下面的例子之一:
function throwing() {
return new Promise((resolve, reject) => { throw new Error('err'); });
}
function rejecting() {
return new Promise((resolve, reject) => { reject(new Error('err')); });
}
describe('test', () => {
it('works', async () => {
throwing();
rejecting();
console.log('came here');
});
});
$ npx mocha test.js
test
came here
✓ works
[some UnhandledPromiseRejectionWarnings here]
1 passing (6ms)
这两者都不会被测试捕获,因为函数成功执行时返回了promise,测试块也完成了,但失败发生在以后。如果您的函数返回promise,只需在测试中对其执行await
,以确保获得promise结果:
describe('test', () => {
it('works', async () => {
await throwing();
await rejecting();
console.log('came here');
});
});
$ npx mocha test.js
test
1) works
0 passing (6ms)
1 failing
1) test
works:
Error: err
at test.js:4:51
at new Promise (<anonymous>)
at throwing (test.js:4:10)
at Context.<anonymous> (test.js:13:11)
at processImmediate (internal/timers.js:439:21)
https://stackoverflow.com/questions/56762035
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