How to assert that the response body contains strings

Ask the Experts and Postman Tips
1

Hi,

New to Postman and I would appreciate a little help.

I have the following response body and I would like to assert that “token_data” contains the access_token and refresh_token that both have strings.
{
“token_data”:{
“access_token”: “string”,
“refresh_token”: “string”
}
}

Help? :slight_smile:

2

Hello,

Yes it is possible.

You need to use type of.

Snippet below:

pm.test("Data Type is correct for access_token " , function(){
pm.expect(typeof(resp.token_data[0].access_token) === “string”).to.be.true;
});

pm.test("Data Type is correct for refresh_token " , function(){
pm.expect(typeof(resp.token_data[0].refresh_token) === “string”).to.be.true;
});

1 Like
3

Another way to write the tests in addition to how @bpricilla demonstrated would be below:

pm.test('Access token is a string', function(){
  const jsonData = pm.response.json();
  pm.expect(jsonData.token_data).to.have.property('access_token').and.to.be.a('string');
}

What’s nice about this method is that if you also want to test the value, you could change it to something like this:

pm.test('Access token has correct string', function(){
  const jsonData = pm.response.json();
  const expectedValue = 'my_access_token_expected_value';
  pm.expect(jsonData.token_data).to.have.property('access_token', expectedValue);
}
3 Likes