I have some asynchronous (I/O bound) tasks to do, and then I want to use Chai to assert the returned value. Instead of writing a piece of code like this:
expect(await taskA.someAsync()).to.be.eq(something); expect(await taskB.someAsync()).to.be.eq(something);
I want to wait for all tasks to complete, use await Promise.all([taskA.someAsync(), taskB.someAsync()]), and then expect or ## one by one #assertResult.
type TransactionInfo = {
txn: Promise<any>; // 要等待的异步任务
assertion: Chai.Assertion // 要在txn结果上运行的断言
}
const assertAll = async function(...txns: TransactionInfo[]) {
let values = await Promise.all(allTxns);
for (let txnInfo of txns) {
evaluate(txnInfo.assertion)
}
}
What this function does is awaitall txns, and then run each assertion on each txn to verify the returned value.
Chai.Assertion type is correct for assertion. Secondly, I don't know how to instantiate an array of TransactionInfo that contains assertions of different types (like eq or have.lengthOf). Finally, I don't know how to evaluate the assertion object later.
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import { expect } from 'chai'; type TransactionInfo = { txn: Promise<any>; // 要等待的异步任务 assertion: () => void; // 表示要在txn结果上运行的断言函数 }; const assertAll = async function (...txns: TransactionInfo[]) { let values = await Promise.all(txns.map((txnInfo) => txnInfo.txn)); txns.forEach((txnInfo, index) => { txnInfo.assertion(values[index]); }); };Using this code, you can now create an array of TransactionInfo objects, each with its own custom assertion function:
// 示例用法： const txn1: TransactionInfo = { txn: someAsyncTaskA(), assertion: (result) => { expect(result).to.be.eq(something); }, }; const txn2: TransactionInfo = { txn: someAsyncTaskB(), assertion: (result) => { expect(result).to.have.lengthOf(3); }, }; // 使用TransactionInfo对象数组调用assertAll函数 await assertAll(txn1, txn2);