Test failing randomly, around once on five times

Questions / Help
,
1

In a library I am developing I execute the following:

if function_exported?(type, :foo, 0) do
  # some code

When I run my tests, once on five this function will return false, for the same data.

So I was looking to get some more information, and inserted the code below to do some inspection, right before the condition:

if type == FooLib.Foo do
  IO.inspect function_exported?(type, :foo, 0)
  IO.inspect type.foo()
end

But since I added this code, the if condition thereafter now always returns true for the same data… and tests always pass.

Something weird is going on. Any idea?

2

My guess is sometimes the BEAM gets opportunistically lazy about mounting modules (you can change the BEAM vm mode to embedded to solve this). I’m not sure that’s the best solution; if this is the problem it results from sort of race condition. Are there four other async tests that are using that module? Then function_exported? is failing when it happens to be runnning first. Maybe try dropping Code.ensure_loaded?(type) in front, as a better solution than changing how your BEAM is built.

2 Likes
3

thank you