How to use Promise and setTimeout to mock an API call in JavaScript All In One
如何使用 Promise 和 setTimeout 在 JavaScript 中模拟一个 API 调用
args list version
const getMockData = async (data = '', error = 'unknown server error', delay) => {
return new Promise((resolve, reject) => {
setTimeout(() => {
if(!!data) {
resolve({
type: 'Success ✅',
data,
});
} else {
reject({
type: 'Error ❌',
message: error,
});
}
}, delay || 1000);
});
}
// test cases
(async () => {
try {
const success = await getMockData([1,2,3]);
console.log(success.data);
} catch (err) {
console.log(err.message);
}
try {
const error = await getMockData('', '404 not found error', 3000);
console.log(error);
} catch (err) {
console.log(err.message);
}
})();
args object version
const getMockData = async (options = {
data: '',
error: 'unknown server error',
delay: null
}) => {
const {data, error, delay} = options;
return new Promise((resolve, reject) => {
setTimeout(() => {
if(!!data) {
resolve({
type: 'Success ✅',
data,
});
} else {
reject({
type: 'Error ❌',
message: error,
});
}
}, delay || 1000);
});
}
// test cases
(async () => {
try {
const success = await getMockData({data: [1,2,3]});
console.log(success.data);
} catch (err) {
console.log(err.message);
}
try {
const error = await getMockData({error: '404 not found error', delay: 3000});
console.log(error);
} catch (err) {
console.log(err.message);
}
})();
destructured parameterwith default value assignment
function aobject arguments default values
const getMockData = async ({
data = '',
error = 'unknown server error',
delay = null,
}) => {
return new Promise((resolve, reject) => {
setTimeout(() => {
if(!!data) {
resolve({
type: 'Success ✅',
data,
});
} else {
reject({
type: 'Error ❌',
message: error,
});
}
}, delay || 1000);
});
}
// test cases
(async () => {
try {
const success = await getMockData({data: [1,2,3]});
console.log(success.data);
} catch (err) {
console.log(err.message);
}
try {
const error = await getMockData({error: '404 not found error', delay: 3000});
console.log(error);
} catch (err) {
console.log(err.message);
}
})();
https://www.typescriptlang.org/docs/handbook/2/objects.html#optional-properties
https://stackoverflow.com/questions/894860/set-a-default-parameter-value-for-a-javascript-function
API 请求 timeout 超时重试
todo...
demos
// await new Promise((resolve, reject) => {setTimeout(() => resolve(`OK ✅`), 3000)});
// await new Promise((resolve, reject) => {setTimeout(() => reject(`Error ❌`), 3000)});
;(async () => {
console.log(`promise delay 3 seconds`)
// delay
await new Promise((resolve, reject) => {setTimeout(() => resolve(`OK ✅`), 3000)});
// await new Promise((resolve, reject) => {setTimeout(() => reject(`Error ❌`), 3000)});
console.log(`promise delay 3 seconds ✅`)
const antiCrawler = document.querySelector(`#anti-crawler`);
if(antiCrawler?.firstElementChild) {
// auto add original url
antiCrawler.firstElementChild.href = window.location.href;
antiCrawler.firstElementChild.innerText = window.location.href;
}
})();
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