Generating unique values

[jonaslagoni]

Hey!

I am trying to generate unique ids however I am having some troubles with it. I have tried adding a list to which ids have already been generated and then discard any that matches. questionIdGenOptions.alreadyGeneratedQuestions is an array of strings. Utils.Contains is a function which returns true if the given array contains the corresponding string otherwise false.

func QuestionIdGen(questionIdGenOptions *QuestionIdGenOptions) gopter.Gen{
	if questionIdGenOptions != nil && questionIdGenOptions.alreadyGeneratedQuestions == nil {
		var newAlreadyGeneratedQuestions = []string{}
		questionIdGenOptions.alreadyGeneratedQuestions = &newAlreadyGeneratedQuestions
	}
	pgen := gen.PtrOf(gen.AnyString())
	if questionIdGenOptions != nil {
		pgen = pgen.SuchThat(
			func(generatedId *string) bool {
				//Some characters look the same however their bytes are not i.e. it is therefore unique.
				if questionIdGenOptions.GenUniqueId != nil && *questionIdGenOptions.GenUniqueId == true && (generatedId == nil || Utils.Contains(*questionIdGenOptions.alreadyGeneratedQuestions, *generatedId)) {
					return false
				}

				newAlreadyGeneratedQuestions := append(*questionIdGenOptions.alreadyGeneratedQuestions, *generatedId)
				questionIdGenOptions.alreadyGeneratedQuestions = &newAlreadyGeneratedQuestions
				return true
			})
	}
	return pgen
}

However atm. with this if statement, the wrapper generator which uses this function fails to generate anything... And I am unsure why almost like something internal error is happening. If I remove it everything works fine except the ids are not unique. Is there another way of doing it or?

[jonaslagoni]

Soo I test simply give up after (fixed any underlying problems), however the usecase are still relevant, do you want any functionality which can do this in a reproducing manner? Or should I find external libraries for this?

[untoldwind]

Sorry for the long wait ... (I guess the situation is kind of messed up all around the world).

Obviously you are doing a sort of stateful testing, i.e. the function under test is not a pure-function since the outcome depends on the previous calls to it. As a rule of thumb one should use command-based tests for this kind of situation.

Maybe there is a somewhat "simple" example that could be added to the library reflecting a use-case like this.