How to compare if two structs, slices or maps are equal?

Question

I want to check if two structs, slices and maps are equal.

But I\'m running into problems with the following code. See my comments at the relevant lines.

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Answer 1

reflect.DeepEqual is often incorrectly used to compare two like structs, as in your question.

cmp.Equal is a better tool for comparing structs.

To see why reflection is ill-advised, let's look at the documentation:

Struct values are deeply equal if their corresponding fields, both exported and unexported, are deeply equal.

....

numbers, bools, strings, and channels - are deeply equal if they are equal using Go's == operator.

If we compare two time.Time values of the same UTC time, t1 == t2 will be false if their metadata timezone is different.

go-cmp looks for the Equal() method and uses that to correctly compare times.

Example:

m1 := map[string]int{
    "a": 1,
    "b": 2,
}
m2 := map[string]int{
    "a": 1,
    "b": 2,
}
fmt.Println(cmp.Equal(m1, m2)) // will result in true