I've a terratest where I get an output from terraform like so s := "[a b]". The terraform output's value = toset([resource.name]), it's a set of strings.
Apparently fmt.Printf("%T", s) returns string. I need to iterate to perform further validation.
I tried the below approach but errors!
var v interface{}
if err := json.Unmarshal([]byte(s), &v); err != nil {
fmt.Println(err)
}
My current implementation to convert to a slice is:
s := "[a b]"
s1 := strings.Fields(strings.Trim(s, "[]"))
for _, v:= range s1 {
fmt.Println("v -> " + v)
}
Looking for suggestions to current approach or alternative ways to convert to arr/slice that I should be considering. Appreciate any inputs. Thanks.
Actually your current implementation seems just fine.
You can't use JSON unmarshaling because JSON strings must be enclosed in double quotes ".
Instead strings.Fields does just that, it splits a string on one or more characters that match unicode.IsSpace, which is \t, \n, \v. \f, \r and .
Moeover this works also if terraform sends an empty set as [], as stated in the documentation:
returning [...] an empty slice if s contains only white space.
...which includes the case of s being empty "" altogether.
In case you need additional control over this, you can use strings.FieldsFunc, which accepts a function of type func(rune) bool so you can determine yourself what constitutes a "space". But since your input string comes from terraform, I guess it's going to be well-behaved enough.
There may be third-party packages that already implement this functionality, but unless your program already imports them, I think the native solution based on the standard lib is always preferrable.
unicode.IsSpace actually includes also the higher runes 0x85 and 0xA0, in which case strings.Fields calls FieldsFunc(s, unicode.IsSpace)