Environmental variable not updated

[ivaylogeorgiev1]

Hello,

I have pre-request script on collection level with a method (self invoked )that uses the environment variable X
On request level i have pre request script that updates the environment variable X
then I'm calling the method from the collection level pre -request script and the X is not updated.

Is that a bug ?

[harryi3t]

Order of execution is

collection pre-req script -> req pre-req script -> req test script -> collection test script

So, any variable set from req level pre-req script will not be available in the collection pre-req script

[ivaylogeorgiev1]

the variable is updated at the end when you inspect it, but it seems that when the collection level pre request script runs some kind of snapshots of the variables is made and the update of the request pre request script change on the variable is not considered.

[harryi3t]

Yes variable will be updated but because of the order of execution collection pre-req script cannot access it

// Order of execution

collection pre-req script  // Tries to get variable X: Not found
  |
  V
req pre-req script // create variable X
  |
  V
req test script
  |
  V
collection test script

// In the end: X is present

[ivaylogeorgiev1]

here is an example- "try changing this value" - change this value in different requests

create test variable( in the case global) testVariable

Collection pre request scirpt

(function TestFunction(){
    
    console.log("Pre- request Script Folder = " + pm.globals.get("testVariable"));
    
    logTheVariable = function() {
        console.log(pm.globals.get("testVariable"));
    }
} ());

request pre req script

console.log("*1* " + pm.globals.get("testVariable"));
pm.globals.set("testVariable", "try changing this value");
console.log("*2* " + pm.globals.get("testVariable"));
logTheVariable();

so 2 gives the updated value but logTheVariable(); gives us the old value. At the end the variable is updated and if you call run again 1 will give you the new value

some kind of snapshot of the variables is made when collection pre req is called which i believe is a bug

[harryi3t]

@ivaylogeorgiev1 I was able to reproduce this.
Sharing javascript global variables or functions across scripts is not an intended feature and not reliable. It may work in some cases.

logTheVariable should not even be accessible to the request script.
If you are using this behaviour to keep common functions in collection-level scripts and reusing them in other request scripts, I would recommend you to serialize the common functions and store it in some Postman variable (global or local* variables) and the eval it in other places

// Collection script
function logTheVariable () {
  ...
}
pm.variables.set('logTheVariable', logTheVariable.toString())

// Request script
eval(pm.variables.get('logTheVariable'))
logTheVariable()

[ivaylogeorgiev1]

yes, this work around is clear to me but I'm still thinking that this is a bug.

[lsloan]

@harryi3t, you wrote:

Sharing javascript global variables or functions across scripts is not an intended feature and not reliable. It may work in some cases.

Although it's not an intended feature, I think it's one that's desperately needed. Are there any plans to support it in the near future?

I think definitions from the various scripts should cascade:

1. Collection pre-request
2. Folder pre-request
3. Request pre-request
4. Collection test
5. Folder test
6. Request test

That is, code in script 𝒏 should be able to access definitions from scripts 1 through 𝒏.