# Macro Expansion Error in basic @testset

**URL:** <https://discourse.julialang.org/t/macro-expansion-error-in-basic-testset/95555>\
**Category:** General Usage\
**Tags:** package, testing\
**Created:** [March 4, 2023, 7:08pm UTC](https://discourse.julialang.org/t/macro-expansion-error-in-basic-testset/95555 "2023-03-04T19:08:19Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![JacobC](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jacobc/32/51809_2.png) [@JacobC](https://discourse.julialang.org/u/JacobC)\
**Post date:** [March 4, 2023, 7:08pm UTC](https://discourse.julialang.org/t/macro-expansion-error-in-basic-testset/95555/1 "2023-03-04T19:08:19Z")

</div>

Anytime I get something that evaluates false inside of a testset I get a macro expansion error. The testset runs as expected and gives a summary as expected, but throws the macro expansion error first, and I am a bit unsure why. I don’t think it will affect my testing, but I just want to check. Here is the most basic example

```plaintext
using Test
@testset "Macro expansion error" begin
    @test false
    @test true
end

```

I feel like maybe I messed something up somewhere, but I deleted the REPL and started a new one (I am using VS Code) and it didn’t make a difference.  
Here is the output

```plaintext
Macro expansion error: Test Failed at REPL[4]:2
  Expression: false
Stacktrace:
 [1] macro expansion
   @ C:\Users\child\AppData\Local\Programs\Julia-1.7.1\share\julia\stdlib\v1.7\Test\src\Test.jl:445 [inlined]
 [2] macro expansion
   @ REPL[4]:2 [inlined]
 [3] macro expansion
   @ C:\Users\child\AppData\Local\Programs\Julia-1.7.1\share\julia\stdlib\v1.7\Test\src\Test.jl:1283 [inlined]
 [4] top-level scope
   @ REPL[4]:2
Test Summary: | Pass Fail Total
Macro expansion error | 1 1 2
ERROR: Some tests did not pass: 1 passed, 1 failed, 0 errored, 0 broken.

```

The tests still run, so if it is not a problem I will move forward, I just wanted to know.  
Thanks so much!  
Jacob

---

<div class="post-metadata">

**Author:** ![CameronBieganek](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/cameronbieganek/32/6915_2.png) [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)\
**Post date:** [March 4, 2023, 8:39pm UTC](https://discourse.julialang.org/t/macro-expansion-error-in-basic-testset/95555/2 "2023-03-04T20:39:38Z")

</div>

Are you referring to the part of the output that says `Macro expansion error`? That’s just the value of the string that you wrote after `@testset`. There is no actual macro expansion error. All of the `macro expansion` entries in the stacktrace are a bit noisy, but what you really care about is the location in your source code of the failed test.

Here is a somewhat more realistic example. Suppose you have a file called `test_foo.jl` that contains the following code:

```julia
using Test

bar() = 1 
foo(x) = 2x

@testset "hello world" begin
    @test foo(1) == 3
end

```

Now in the REPL we observe the following if we `include` that file:

```julia
julia> include("test_foo.jl")
hello world: Test Failed at /Users/cameron/test_foo.jl:7
  Expression: foo(1) == 3
   Evaluated: 2 == 3
Stacktrace:
 [1] macro expansion
   @ /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Test/src/Test.jl:464 [inlined]
 [2] macro expansion
   @ ~/test_foo.jl:7 [inlined]
 [3] macro expansion
   @ /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Test/src/Test.jl:1357 [inlined]
 [4] top-level scope
   @ ~/test_foo.jl:7
Test Summary: | Fail Total Time
hello world | 1 1 0.4s
ERROR: LoadError: Some tests did not pass: 0 passed, 1 failed, 0 errored, 0 broken.
in expression starting at /Users/cameron/test_foo.jl:6

```

The location of the failed test is given at the top where it says

```julia
Test Failed at /Users/cameron/test_foo.jl:7

```

You can also see the location of the failed test by looking at the fourth entry in the stacktrace:

```julia
@ ~/test_foo.jl:7

```

A failing `@test` will always throw an exception, even when it is inside a `@testset`. The nice thing about `@testset` is that it gathers all the thrown exceptions from failed tests that occur inside it, rather than failing on the first failed test. However, any exception inside a `@testset` other than a failed test will immediately halt the test set, as we can see in the following example:

```julia
julia> @testset "hello world" begin
           sqrt(-1)
           @test false
           @test true
           @test false
       end
hello world: Error During Test at REPL[21]:1
  Got exception outside of a @test
  DomainError with -1.0:
  sqrt will only return a complex result if called with a complex argument. Try sqrt(Complex(x)).
  Stacktrace:
    [1] throw_complex_domainerror(f::Symbol, x::Float64)
      @ Base.Math ./math.jl:33
    [2] sqrt
      @ ./math.jl:591 [inlined]
    [3] sqrt(x::Int64)
      @ Base.Math ./math.jl:1372
    # ... Removed for clarity ...
Test Summary: | Error Total Time
hello world | 1 1 0.0s
ERROR: Some tests did not pass: 0 passed, 0 failed, 1 errored, 0 broken.

```

---

<div class="post-metadata">

**Author:** ![JacobC](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jacobc/32/51809_2.png) [@JacobC](https://discourse.julialang.org/u/JacobC)\
**Post date:** [March 4, 2023, 9:41pm UTC](https://discourse.julialang.org/t/macro-expansion-error-in-basic-testset/95555/3 "2023-03-04T21:41:25Z")

</div>

Thanks so much! I guess I misunderstood the stack trace macro expansion, I thought it was saying I had a legitimate error, but from your explanation I think I am understanding that it is just a thrown exception for a failed test and a trace to where it was. Also it is good to know that normal errors still stop the code inside of a test set. Thanks for the in depth answer!  
Thank you!