zf

zenflows testing
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unmatched_return.ex (1594B)

      1 defmodule Dialyxir.Warnings.UnmatchedReturn do
      2   @moduledoc """
      3   The invoked expression returns a union of types and the call does
      4   not match on its return types using e.g. a case or wildcard.
      5 
      6   ## Example
      7 
      8       defmodule Example do
      9         require Integer
     10 
     11         def ok() do
     12           n = :rand.uniform(100)
     13 
     14           multiple_returns(n)
     15 
     16           :ok
     17         end
     18 
     19         defp multiple_returns(n) do
     20           if Integer.is_even(n) do
     21             :ok
     22           else
     23             {:error, "error"}
     24           end
     25         end
     26       end
     27 
     28     This would NOT result in a warning:
     29 
     30       defmodule Example do
     31         require Integer
     32 
     33         def ok() do
     34           n = :rand.uniform(100)
     35 
     36           multiple_returns(n)
     37 
     38           :ok
     39         end
     40 
     41         defp multiple_returns(n) do
     42           if Integer.is_even(n) do
     43             :ok
     44           else
     45             :error
     46           end
     47         end
     48       end
     49   """
     50   @behaviour Dialyxir.Warning
     51 
     52   @impl Dialyxir.Warning
     53   @spec warning() :: :unmatched_return
     54   def warning(), do: :unmatched_return
     55 
     56   @impl Dialyxir.Warning
     57   @spec format_short([String.t()]) :: String.t()
     58   def format_short(_) do
     59     "The expression produces multiple types, but none are matched."
     60   end
     61 
     62   @impl Dialyxir.Warning
     63   @spec format_long([String.t()]) :: String.t()
     64   def format_long([type]) do
     65     pretty_type = Erlex.pretty_print_type(type)
     66 
     67     """
     68     The expression produces a value of type:
     69 
     70     #{pretty_type}
     71 
     72     but this value is unmatched.
     73     """
     74   end
     75 
     76   @impl Dialyxir.Warning
     77   @spec explain() :: String.t()
     78   def explain() do
     79     @moduledoc
     80   end
     81 end