Request reuse in Postman - automated-tests

Question

Our team wants to automate our REST API testing. Right now, we have a collection of Postman requests and make them jump through hoops manually.
We could create a collection/folder for each testing scenario, but that would mean a ton of duplication. Our API is still under heavy development and I really don't want to fix the same thing at twenty places after it changes.
I would like to have each endpoint request only once in a collection and some kind of independent logic that can execute them in an arbitrary order. I know Postman doesn't support request reuse in any clean way, so I am looking for at least a hacky way how to do it.

Answer 1

Create a file to load into the Postman Collection Runner, with the following structure:
[{
"testSequence": ["First request name", "Second request name", "..." ],
"anyOtherData": "Whatever the request needs",
"evenMoreData": "Whatever the request needs",
"...": "..."
},{
"testSequence": ["Login", "Check newsfeed", "Send a picture", "Logout" ],
"username": "Example",
"password": "correcthorsebatterystaple",
},{
"...": "keep the structure for any other test scenario or request sequence"
}]
Put all your test sequences in that file, then make Postman check the list after each request and decide what to execute next. This can be done e. g. in a "tests block" of the whole collection:
// Use the mechanism only if there is a test scenario file
// This IF prevents the block from firing when running single requests in Postman
if (pm.iterationData.get("testSequence")) {
// Is there another request in the scenario?
var sequence = pm.globals.get("testSequence");
if ((sequence instanceof Array) && (sequence.length > 0)) {
// If so, set it as the next one
var nextRequest = sequence.shift();
pm.globals.set("testSequence", sequence);
postman.setNextRequest(nextRequest);
} else {
// Otherwise, this was the last one. Finish the execution.
postman.setNextRequest(null);
}
}
If your requests need to use different data during different runs, you can define the data in the input file and use them as variables in the request.