How do you change the "Cap" value of an []map[string]interface{} in go lang?

Question

I am trying to do some testing with ginkgo and gomega, I get down to the assertion error

Expected
        <[]map[string]interface {} | len:1, cap:1>: []
To equal
        <[]map[string]interface {} | len:1, cap:4>: []

I believe that the test is failing because they do not have equal "cap" values, Is there a way to make these cap values equal? Also, would having the items be in different orders cause these test to fail?

thank you

What is ginko, what is gomega? And no, you cannot control cap of a (used) map. — Volker
– Volker, Commented Apr 27, 2021 at 5:16
ginko is BDD Testing framework and gomega is matcher/assertion library which goes in hand — advay rajhansa
– advay rajhansa, Commented Apr 27, 2021 at 5:19
tour.golang.org/moretypes/13 has an example of making an array with non-default capacity. You might want something like make([]map[string]interface{}, 1, 4). — Tinkerer
– Tinkerer, Commented Apr 27, 2021 at 14:30

advay rajhansa · Accepted Answer · 2021-04-27 05:18:09Z

0

This shows that you have a slice of maps which had some data. This data is now removed. But slice capacity won't decrease. If you need to check if slice is empty, you can go to BeEmpty gomega matcher.

If you want an empty slice with known capacity, you can do it like:

obj := make([]map[string]interface{}, 4) // 4 is size you need

answered Apr 27, 2021 at 5:18

advay rajhansa

1,26711 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

9 Comments

benwasin97 Over a year ago

How would I add data to this after initializiation?

advay rajhansa Over a year ago

obj[0] = your map

benwasin97 Over a year ago

previously i had it declared like ` expected = []map[string]interface{}{ { "name": expectedCompany.Name, "orders": [] interface {} } } ` but declaring it like this doesn't seem to work with the new make 4

advay rajhansa Over a year ago

obj[0] = map[string]interface{}{ "name": your data }

benwasin97 Over a year ago

I get expected operand, found '{'

|

Collectives™ on Stack Overflow

How do you change the "Cap" value of an []map[string]interface{} in go lang?

1 Answer 1

9 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

9 Comments

Your Answer

Sign up or log in

Post as a guest

Related