# Scope Issues of Exported Functions in Module
**URL:** https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784
**Category:** New to Julia
**Tags:** question
**Created:** [November 27, 2023, 6:22am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784 "2023-11-27T06:22:19Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@Ian\_Harreschou](https://discourse.julialang.org/u/Ian_Harreschou)
#### Post date: [November 27, 2023, 6:22am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/1 "2023-11-27T06:22:19Z")
Probably a basic question and answer I am searching for here, but I am trying to get into package development and it has been quite difficult. This time around, I have made much more progress, but just ran into issues with running `Test` which is baffling me. More than likely comes down to my confusion about scopes and making sure I’ve loaded the proper environments.
I have a module that I want to create, called `FinancialAccounting`. I do an `include("loans.jl")`, and inside `loans.jl` we have a simple function saying hello, and another outputting a number.
In my test file, I have a testset looking for the return of the “hello” function, as well as the number. The `what_is_x` and `hello_package` functions appear, so I think I am loading the module properly. The problem I have, is that when I type into the REPL `FinancialAccounting.hello_package()` it returns the correct phrase, but is `T{Nothing}`. When I just straight up enter `hello_package()` into the same REPL, it returns the proper phrase, and is `T{String}`. This disconnect is causing issues in the test statements and I don’t know how to fix them.
Module File:
```julia
module FinancialAccounting
export hello_package, what_is_x
include("loans.jl")
end
```
Included File:
```julia
function hello_package()
println("Hello FinancialAccounting!")
end
function what_is_x()
2
end
```
runtests.jl
```julia
using FinancialAccounting
using Test
@testset "FinancialAccounting.jl" begin
@test FinancialAccounting.hello_package() == "Hello FinancialAccounting!"
@test FinancialAccounting.what_is_x() == 2
@test FinancialAccounting.hello_package() != "Hello World!"
end
```
---
### Author:  [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)
#### Post date: [November 27, 2023, 6:43am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/2 "2023-11-27T06:43:09Z")
Hello and welcome to the community 👋
The problem might be that the `hello_package` function doesn’t actually return a string, it _prints_ a string. The function `println` does not return anything.
```julia
julia> a = println("hej")
hej
julia> typeof(a)
Nothing
```
so you can never test this function this way
```julia
@test FinancialAccounting.hello_package() == "Hello FinancialAccounting!"
```
You might be confused because a function that returns a string to the REPL will also cause the string to be printed, similar to if the string had been printed using `println`?
What is the `T` you are writing about? I cannot see it appearing in your code.
---
### Author:  [@Benny](https://discourse.julialang.org/u/Benny)
#### Post date: [November 27, 2023, 6:59am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/3 "2023-11-27T06:59:26Z")
> [@baggepinnen](#):
>
> You might be confused because a function that returns a string to the REPL will also cause the string to be printed, similar to if the string had been printed using `println`?
It’s printed visibly different, though:
```julia
julia> (() -> "hello")()
"hello"
julia> (() -> println("hello"))()
hello
julia> (() -> begin println("hello"); "world" end)()
hello
"world"
```
> [@Ian\_Harreschou](#):
>
> when I type into the REPL `FinancialAccounting.hello_package()` it returns the correct phrase, but is `T{Nothing}`. When I just straight up enter `hello_package()` into the same REPL, it returns the proper phrase, and is `T{String}`.
Assuming that you’re `typeof`ing the returned value consistently, then this would indicate the two functions are in fact different. Check `FinancialAccounting.hello_package === hello_package`. If `true`, then you evaluated a separate function somewhere else that behaves differently.
---
### Author:  [@Ian\_Harreschou](https://discourse.julialang.org/u/Ian_Harreschou)
#### Post date: [November 27, 2023, 6:06pm UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/4 "2023-11-27T18:06:28Z")
`T{String}` was just how I thought the notation was for denoting “type = String”, my mistake. I think it’s something slightly different according to the core/base docs.
I didn’t know that `println` returns a `::Nothing` object, that’s interesting…
---
### Author:  [@Ian\_Harreschou](https://discourse.julialang.org/u/Ian_Harreschou)
#### Post date: [November 27, 2023, 6:18pm UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/5 "2023-11-27T18:18:12Z")
Here’s what I tried running, within the `runtests.jl` and after starting a fresh terminal/REPL instance. I’m starting to think this may be an issue/change in the Julia version, because I am following the official walkthrough for package creation and this is where I got all the example tests ([How to develop a Julia package](https://julialang.org/contribute/developing_package/)).
The comparison they use with the `println` and the true `::String` might be incorrect now.
I believe everything in the module is working though. I can access my custom `Loan` struct, as well as the other functions and attributes from `loans.jl`, so I think my exporting is correct. I appreciate the help!
```julia
julia> names(Main)
5-element Vector{Symbol}:
:Base
:Core
:InteractiveUtils
:Main
:ans
julia> @ __MODULE__
Main
julia> FinancialAccounting.
Loan amortization amortization_periods eval hello_package
include what_is_x
julia> typeof(FinancialAccounting.hello_package())
Hello FinancialAccounting!
Nothing
julia> typeof(hello_package())
Hello FinancialAccounting!
Nothing
julia> hello_package() === FinancialAccounting.hello_package()
Hello FinancialAccounting!
Hello FinancialAccounting!
true
```
---
### Author:  [@Benny](https://discourse.julialang.org/u/Benny)
#### Post date: [November 27, 2023, 6:34pm UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/6 "2023-11-27T18:34:28Z")
I doubt it’s a version change, `println` should return `nothing` even 4 years ago. That is either a test doomed to fail or a typo (probably the case).
> [@Ian\_Harreschou](#):
>
> ```julia
> julia> typeof(FinancialAccounting.hello_package())
> Hello FinancialAccounting!
> Nothing
>
> julia> typeof(hello_package())
> Hello FinancialAccounting!
> Nothing
>
> julia> hello_package() === FinancialAccounting.hello_package()
> Hello FinancialAccounting!
> Hello FinancialAccounting!
> true
>
> ```
Good that’s all consistent now.
---
### Author:  [@mkitti](https://discourse.julialang.org/u/mkitti)
#### Post date: [November 27, 2023, 7:42pm UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/7 "2023-11-27T19:42:17Z")
@ChrisRackauckas, your turorial needs fixing.
The following tests will fail.
```julia
using YourPackageName
using Test
@testset "YourPackageName.jl" begin
@test YourPackageName.greet_your_package_name() == "Hello YourPackageName!"
@test YourPackageName.greet_your_package_name() != "Hello world!"
end
```
With the stated definition.
```julia
function greet_your_package_name()
println("Hello YourPackageName!")
end
```
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [November 28, 2023, 12:20am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/8 "2023-11-28T00:20:03Z")
What tutorial? I’m lost and don’t recall writing an example like this.
---
### Author:  [@mkitti](https://discourse.julialang.org/u/mkitti)
#### Post date: [November 28, 2023, 12:25am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/9 "2023-11-28T00:25:00Z")
Hmm. Maybe this is not actually you:
> **[How to develop a Julia package](https://julialang.org/contribute/developing_package/#step_4_test_your_package)**
>
> The official website for the Julia Language. Julia is a language that is fast, dynamic, easy to use, and open source. Click here to learn more.
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [November 28, 2023, 12:44am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784/10 "2023-11-28T00:44:01Z")
Yeah I don’t know who wrote that, but anyways you’d put a PR to [GitHub - JuliaLang/www.julialang.org: Julia Project website](https://github.com/JuliaLang/www.julialang.org) to get it fixed.