邮递员舍入 BigInt [英] Postman rounding off BigInt

问题描述

我试图在 Postman 中设置一个大的 int 值作为环境变量.

但邮递员正在完善它.

有什么办法可以解决这个问题吗?

测试:

var response = JSON.parse(responseBody);for(var i=0; i<=response.Offerings.length ; i++) {if(response.Offerings[i].DisplayName == '三星 Galaxy S9+') {console.log(response.Offerings[i].Id);}}

API 响应:

响应:{产品":[{数量":123，货币代码":CAD"，显示名称":三星 Galaxy S9+"，身份证":1910256760591000500，语言":en-CA"，业务线":[10048]，营销观点":[]，名称":三星 Galaxy S9+"，报价类型":1，}]}

解决方案

问题

是的.所以它不是邮递员，它是基本的Javascript.javascript 中的数字是双精度浮点数.基本上在 Javascript 中，最大的原始数是 56 位，或者他们称之为 MAX_SAFE_INTEGER - 即 9,007,199,254,740,991.大多数语言都是 64 位(9,223,372,036,854,775,807).邮递员发生的事情如下:

• 您的数字需要超过 56 位.
• Javascript 希望为您提供帮助，并尽其所能地进行转换
• JSON.parse(responseBody) 不能转换任何大于 56 位的数字.所以它做得最好，你甚至可以得到一个看起来像一个四舍五入的数字.

小例子是这样的:

let x = 9223372036854775807让 y = BigInt(9223372036854775807)让文本 = x.toString();让 z = parseInt(text, 10);console.log(z)//9223372036854776000

在 javascript 中有解决方案.即几个库，如

I am trying to set a large int value as an environment variable in Postman.

But Postman is rounding it off.

Is there any way I can handle this?

Tests:

var response = JSON.parse(responseBody); 
for(var i=0; i<=response.Offerings.length ; i++) {
    if(response.Offerings[i].DisplayName == 'Samsung Galaxy S9+') {
        console.log(response.Offerings[i].Id); 
    }
} 

API Response:

Response: { 
    "Offerings": [ 
        { 
            "Amount": 123,
            "CurrencyCode": "CAD",
            "DisplayName": "Samsung Galaxy S9+",
            "Id": 1910256760591000500,
            "Language": "en-CA",
            "LineOfBusinesses": [ 10048 ],
            "MarketingViews": [],
            "Name": "Samsung Galaxy S9+",
            "OfferType": 1,
        }
    ]
} 

解决方案

The problem

Yeah. So it isn't postman that is rounding off it is the base Javascript. Numbers in javascript are double precision floats. Bascially in Javascript the largest primitive number is 56 bits or as they call it MAX_SAFE_INTEGER - which is 9,007,199,254,740,991. Most languages are 64 bits(9,223,372,036,854,775,807). What happens in postman is the following:

• You have a number that requires more than 56 bits.
• Javascript wants to help you and converts it as good as it can
• JSON.parse(responseBody) can't convert any number higher than 56 bits. So it does it best and you and up with something that looks like a rounded number.

Small Example would be this:

let x = 9223372036854775807
let y = BigInt(9223372036854775807)
let text = x.toString();
let z = parseInt(text, 10);
console.log(z) // 9223372036854776000

There are solutions to this in javascript. Namely a couple of libraries like "json-bigint". However including that in Postman is not exactly easy. Ironically Postman already makes use of BigInteger, but it does not work when the code you're executing is base javascript. But it is still the reason why @Plurimus solution should work.

What to do

Whenever you need a library in Postman there are ways to load it in using requests. Here users demonstrate how they load libraries mainly stored on cloudflare. And spoiler - json-bigint - is not there. It's an npmjs library which only makes it harder to add. One issue you are definitely going to run into is that Postman pre-requests are async. Which means your library might get loaded, but code that was supposed to use the library has already been executed. Luckily someone already found a hack for that.

A solution

In my solution I have a link to a library at my own personal github that I want to use. Always fork stuff like this. I then use postman get the code. And uses eval to override the JSON object. There is some preliminary code that shows the value before and after loading the library. The request is run in method called main which is an async method added to the pre-request in order to make sure that everything runs synchronously inside that function.

    console.log('hello');
    var libraryLink = 'https://gist.githubusercontent.com/kentkost/f2699eb1dd41e2eb6203f0d0c77a987e/raw/bffae74aa3827ea195c10cf83bce4d78017bdf2d/postman-bigint.js'

    let dummyJson = '{ "value" : 9223372036854775807, "v2": 123 }'
    let obj = JSON.parse(dummyJson)
    console.log(obj.value);
    console.log(JSON.stringify(obj));

    const _dummy = setInterval(() => {}, 300000);

    function sendRequest(req) {
        return new Promise((resolve, reject) => {
            pm.sendRequest(req, (err, res) => {
                if (err) {
                    return reject(err);
                }

                return resolve(res);
            })
        });
    }

    (async function main() {
        let result1 = await sendRequest(libraryLink);
        eval(result1.text());
        
        let newObj = JSON.parse(dummyJson);
        console.log(newObj.value);
        pm.environment.set("someVar", newObj.value);
        console.log(JSON.stringify(newObj));
        console.log('bye');
        clearInterval(_dummy)
    })();

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