It’s cryptic, but dialyxir is always right.
kokolegorille
BitGonzo
How is that right, though? When it is talking about a match which happens successfully, which is being asserted in my tests? I don’t understand how it can never match that type when the type is being matched in Elixir.
The line is very simply:
case result do
{:ok, response} -> {:ok, Response.adapt(response)}
end
Unless I have to define this in another way?
0
NobbZ
BitGonzo
That’s:
result = case method do
"GET" -> get(url)
end
Where get is a function from Tesla.get.
Together:
result = case method do
"GET" -> get(url, headers)
"POST" -> post(url, headers)
end
case result do
{:ok, response} -> {:ok, Response.adapt(response)}
{:error, error} -> {:error, ResponseError.adapt(error)}
_ -> {:error, ResponseError.adapt(%{reason: :unknown})}
end
0
NobbZ
So dialyzer is totally right.
Tesla.get/* and Tesla.post/* all are returning Tesla.Env.t according to their @spec. A Tesla.Env.t will never match a {:ok, _} as it is a struct, not a tuple.
If though Tesla.get/* does return a tuple instead, you need to file a bugreport at tesla to fix their specs (or implementation).
1
BitGonzo
I don’t understand. That code works – the result of Tesla.get is a tuple with {:ok, response} or {:error, struct (with reason)}?
In that case - if this is a bug in their spec/impl, apart from telling Tesla about it, what would be the proper way to handle this? Patch the spec myself? Wait for it to be fixed? Tell dialyzer to ignore?
1
NobbZ
Its easiy.
You are using Tesla.get/1, which is @speced to return Tesla.Env.t, but implemented to return {:ok, any()} | {:error, any()} (or something similar).
You are running dialyzer in the context of your application, so dialyzer will trust in the specs of external libraries without validating them.
If you were running dialyzer in the context of Tesla it will probably complain that the functions do not fullfill their contract (do not remember the exact message).
1
NobbZ
The proper way is to file an issue, perhaps even prepare and do a PR and then ignore the warning until the next release of tesla.
After the next release of tesla do whatever is appropriate for the way they used to fix.
1
BitGonzo
BitGonzo
What about? Likely because of pos_integer() instead of integer()?
The call 'Elixir.Appsignal':set_gauge("database_size",pos_integer()) breaks the contract ('Elixir.String':t(),float() | integer()) -> 'ok'
I think I’m just going to add all of these to my .dialyzerignore file.
0