Collection variable doesn't update in Postman

I've got pre-requests with 2 pm.sendRequest. One of them depends on variable from first response. They work with setTimeout.

//I set Timeout because updateInfoRequest needs to wait and get it from h2hRequest response
setTimeout("updateInfo", 3000)

updateInfoBody = {"orderId":pm.collectionvariables.get("orderId")}

updateInfoRequest = {
there is connection info
body:JSON.stringify(updateInfoBody)
}

pm.sendRequest(h2hRequest, function(error, h2hResponse){
pm.collectionvariables.set(h2hResponse.json().orderId
})

function updateInfo(){
pm.sendRequest(updateInfoRequest, function(error, updateInfoResponse){
})
}

h2hRequest works. It takes orderId. It doesn't put in orderId variable after the first call. But I see the value in collection variables. If run it again - orderId is in variable. But it is the last orderId not new.

I use only Request Tab, not flow or anything else.

How to make pre-request get new orderId every time?

clear or unset commands doesn't help.

Local pre-request variable answers ReferenceError.

Overview

I made two requests with scrips to get/set collection variables. It will loop call request depend on variables. All variables handling on Pre request or Post Request (aka tests tab in old version)

Color Codes

Collection Variables : Blue

Call Order : Red

Pre Request/Post Response :Circle Blue

Request : Green

Start or End : Orange

Collection Variables

• orderIds: Array data, will assign orderId
• orderId: will call h2hRequest input query
• responseOrderId: After call h2hRequest parse orderId of JSON response

Mock Server

Provides two APIs

h2hRequest

URL

GET /h2h/?{orderId}

Response

{
    "orderId": "{Order ID}",
    "name": "Name {Order ID}",
    "description": "Get Order"
}

updateInfoRequest

URL

POST /update-info/

Input Body

{
    "orderId": {Order ID},
    "name": "Name {Order ID}"
}

Response

{
    "orderId": {Order ID},
    "name": "Name {Order ID}",
    "description": "Update Order"
}

mock-server.js

const express = require('express');
const app = express();
const port = 3000;

app.use(express.json()); // To parse JSON bodies

// GET /h2h endpoint
app.get('/h2h', (req, res) => {
    const orderId = req.query.orderId;
    if (orderId === undefined || orderId === null) {
        return res.status(400).json({ error: 'orderId is required' });
    }
    console.log("/h2h" + orderId);
    res.json({
        orderId: orderId,
        name: `Name ${orderId}`,
        description: 'Get Order'
    });
});

// POST /update-info endpoint
app.post('/update-info', (req, res) => {
    const { orderId } = req.body;
    if (orderId === undefined || orderId === null) {
        return res.status(400).json({ error: 'orderId is required' });
    }
    console.log("/update-info" + orderId);
    res.json({
        orderId: orderId,
        name: `Name ${orderId}`,
        description: 'Update Order'
    });
});

app.listen(port, () => {
    console.log(`Server is running on http://localhost:${port}`);
});

Install dependency Run Mock Server

npm install express
node mock-server.js

Client Postmen

Import this 1-demo.postman_collection.json by Postman

{
    "info": {
        "_postman_id": "4c3eea37-233b-403d-b6db-b4810d80bc9a",
        "name": "1-demo",
        "schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json",
        "_exporter_id": "1826150"
    },
    "item": [
        {
            "name": "h2hRequest",
            "event": [
                {
                    "listen": "test",
                    "script": {
                        "exec": [
                            "const responseJson = pm.response.json();\r",
                            "pm.collectionVariables.set(\"responseOrderId\", responseJson.orderId)\r",
                            "\r",
                            "console.log(\"responseOrderId: \" + pm.collectionVariables.get(\"responseOrderId\"))\r",
                            ""
                        ],
                        "type": "text/javascript",
                        "packages": {}
                    }
                },
                {
                    "listen": "prerequest",
                    "script": {
                        "exec": [
                            "let orderIds = JSON.parse(pm.collectionVariables.get(\"orderIds\"));\r",
                            "pm.collectionVariables.set(\"orderId\", orderIds.shift())\r",
                            "pm.collectionVariables.set(\"orderIds\", JSON.stringify(orderIds));\r",
                            "orderIds = JSON.parse(pm.collectionVariables.get(\"orderIds\"));\r",
                            "\r",
                            "if (pm.collectionVariables.get(\"orderId\")){\r",
                            "    pm.execution.setNextRequest(\"updateInfoRequest\"); // <- Next Request Name\r",
                            "} else {\r",
                            "    console.log(\"End\")\r",
                            "    pm.execution.setNextRequest(null);\r",
                            "}"
                        ],
                        "type": "text/javascript",
                        "packages": {}
                    }
                }
            ],
            "request": {
                "method": "GET",
                "header": [],
                "url": {
                    "raw": "http://localhost:3000/h2h?orderId={{orderId}}",
                    "protocol": "http",
                    "host": [
                        "localhost"
                    ],
                    "port": "3000",
                    "path": [
                        "h2h"
                    ],
                    "query": [
                        {
                            "key": "orderId",
                            "value": "{{orderId}}"
                        }
                    ]
                }
            },
            "response": []
        },
        {
            "name": "updateInfoRequest",
            "event": [
                {
                    "listen": "prerequest",
                    "script": {
                        "exec": [
                            ""
                        ],
                        "type": "text/javascript",
                        "packages": {}
                    }
                },
                {
                    "listen": "test",
                    "script": {
                        "exec": [
                            "let orderIds = JSON.parse(pm.collectionVariables.get(\"orderIds\"));\r",
                            "\r",
                            "if (orderIds.length > 0){\r",
                            "    pm.execution.setNextRequest(\"h2hRequest\"); // <- next GET Request Name\r",
                            "} else {\r",
                            "    console.log(\"This is final step\")\r",
                            "    pm.execution.setNextRequest(null);\r",
                            "}"
                        ],
                        "type": "text/javascript",
                        "packages": {}
                    }
                }
            ],
            "request": {
                "method": "POST",
                "header": [],
                "body": {
                    "mode": "raw",
                    "raw": "{\r\n    \"orderId\": {{responseOrderId}},\r\n    \"name\": \"Name {{responseOrderId}}\"\r\n}",
                    "options": {
                        "raw": {
                            "language": "json"
                        }
                    }
                },
                "url": {
                    "raw": "http://localhost:3000/update-info",
                    "protocol": "http",
                    "host": [
                        "localhost"
                    ],
                    "port": "3000",
                    "path": [
                        "update-info"
                    ]
                }
            },
            "response": []
        }
    ],
    "event": [
        {
            "listen": "prerequest",
            "script": {
                "type": "text/javascript",
                "exec": [
                    ""
                ]
            }
        },
        {
            "listen": "test",
            "script": {
                "type": "text/javascript",
                "exec": [
                    ""
                ]
            }
        }
    ],
    "variable": [
        {
            "key": "orderIds",
            "value": "[1001, 1002, 1003]",
            "type": "string"
        },
        {
            "key": "orderId",
            "value": "1001",
            "type": "string"
        },
        {
            "key": "responseOrderId",
            "value": "null"
        }
    ]
}

After Import

• Note : Wait 3000 (3 seconds) not necessary because the h2hRequest response even it takes long processing time. we just take orderId from response JSON.

h2hRequest

GET http://localhost:3000/h2h?orderId={{orderId}}

In h2hRequest, Pre-request

let orderIds = JSON.parse(pm.collectionVariables.get("orderIds"));
pm.collectionVariables.set("orderId", orderIds.shift())
pm.collectionVariables.set("orderIds", JSON.stringify(orderIds));
orderIds = JSON.parse(pm.collectionVariables.get("orderIds"));

if (pm.collectionVariables.get("orderId")){
    pm.execution.setNextRequest("updateInfoRequest"); // <- Next Request Name
} else {
    console.log("End")
    pm.execution.setNextRequest(null);
}

In h2hRequest, Post-response

const responseJson = pm.response.json();
pm.collectionVariables.set("responseOrderId", responseJson.orderId)

console.log("responseOrderId: " + pm.collectionVariables.get("responseOrderId"))

updateInfoRequest

POST http://localhost:3000/update-info

Input Body with raw JSON option

{
    "orderId": {{responseOrderId}},
    "name": "Name {{responseOrderId}}"
}

In updateInfoRequest, Post-response

let orderIds = JSON.parse(pm.collectionVariables.get("orderIds"));

if (orderIds.length > 0){
    pm.execution.setNextRequest("h2hRequest"); // <- next GET Request Name
} else {
    console.log("This is final step")
    pm.execution.setNextRequest(null);
}

Run Collection

Result

h2hRequest called by orderIds's array number items with each different orderId

---

Update

If you want to re-run the collection

You should reset all collections current value as red rectangle

orderIds : [1001, 1002, 1003] 
orderId : 1001 
responseOrderId : null