javascript - 异步/等待语法错误 : await is only valid in async functions and the top level bodies of modules

Question

我正在做一些关于使用 csvtojson node module 将 csv 文件读取为 json 格式的非常简单的测试。 ，我使用下面的代码作为模板

a,b,c
1,2,3
4,5,6
*/
const csvFilePath='<path to csv file>'
const csv=require('csvtojson')
csv()
.fromFile(csvFilePath)
.then((jsonObj)=>{
    console.log(jsonObj);
    /**
     * [
     *  {a:"1", b:"2", c:"3"},
     *  {a:"4", b:"5". c:"6"}
     * ]
     */ 
})
 
// Async / await usage
const jsonArray=await csv().fromFile(csvFilePath);

我主要关注的是

// Async / await usage

const jsonArray=await csv().fromFile(csvFilePath);

代码部分。所以这是我的代码

// const JSONtoCSV = require("json2csv")
// const FileSystem = require("fs")

async function test()
{
    const data = await CSVtoJSON().fromFile('./input.csv')
    return data
}

let temp = await test()

console.log(temp)

无论我尝试过哪种方式，我总是会收到以下错误

let temp = await test()
           ^^^^^

SyntaxError: await is only valid in async functions and the top level bodies of modules
    at Object.compileFunction (node:vm:352:18)
    at wrapSafe (node:internal/modules/cjs/loader:1031:15)
    at Module._compile (node:internal/modules/cjs/loader:1065:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:79:12)
    at node:internal/main/run_main_module:17:47

或者

const data = await CSVtoJSON().fromFile('./input.csv');
             ^^^^^

SyntaxError: await is only valid in async functions and the top level bodies of modules
    at Object.compileFunction (node:vm:352:18)
    at wrapSafe (node:internal/modules/cjs/loader:1031:15)
    at Module._compile (node:internal/modules/cjs/loader:1065:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:79:12)
    at node:internal/main/run_main_module:17:47

如果我像这样将代码切换为所有顶级

const CSVtoJSON = require("csvtojson")
// const JSONtoCSV = require("json2csv")
// const FileSystem = require("fs")

const data = await CSVtoJSON().fromFile('./input.csv')

console.log(data)

我不明白为什么这不起作用。
编辑:我按照@tasobu 的说明进行了更改。现在我得到的只是一个返回的 promise

const data = (async () => {
    return await CSVtoJSON().fromFile('./input.csv')
})

console.log(data)

Debugger attached.
Promise { <pending> }
Waiting for the debugger to disconnect...

Answer 1

您可以在此处使用 IIFE(了解更多信息 here)

(async function main () {
    // You can use await inside this function block
})();