A Guide to Debugging JavaScript in Postman

Getting started with writing JavaScript code for API tests is not easy. Let’s explore some of the most common errors you might encounter while using Postman.

Last updated: February 2023

Empty response — JSONError: No data, empty input at 1:1

Receiving an empty response from the API and trying to parse it as JSON will fail with this error:

JSONError: No data, empty input at 1:1 ^

Since there is no content, it makes little sense to parse it. In this case, make sure you test for the status code:

pm.test("Status code is 204", () => {
    pm.response.to.have.status(204);
});

You can also check that the response is indeed empty (if this is the expected behavior).

pm.test("Empty response", () => {
    pm.expect(pm.response.text()).to.eql('');
});

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