Fix regression on direct raise of ExUnit.AssertionError

Author: josevalim

lib/ex_unit/lib/ex_unit/assertions.ex

@@ -39,6 +39,10 @@ defmodule ExUnit.AssertionError do
   end
 
   @impl true
+  def exception(message) when is_binary(message) do
+    %ExUnit.AssertionError{message: message}
+  end
+
   def exception(opts) do
     with {:ok, message} when not is_binary(message) <- Keyword.fetch(opts, :message) do
       raise ArgumentError,

lib/ex_unit/test/ex_unit/assertions_test.exs

@@ -63,6 +63,15 @@ defmodule ExUnit.AssertionsTest do
 
   defguardp is_zero(zero) when zero == 0
 
+  test "direct raise" do
+    try do
+      raise ExUnit.AssertionError, "This is a test"
+    rescue
+      error in [ExUnit.AssertionError] ->
+        "This is a test" = error.message
+    end
+  end
+
   test "assert inside macro" do
     assert_ok(42)
   end