Preserve variable metadata during collection from assertion pattern

Closes #4174.

Author: lexmag

lib/ex_unit/lib/ex_unit/assertions.ex

@@ -102,15 +102,15 @@ defmodule ExUnit.Assertions do
     # is not nil nor false. We need to rewrite the if
     # to avoid silly warnings though.
     return =
-        no_warning(quote do
-          if right do
-            right
-          else
-            raise ExUnit.AssertionError,
-              expr: expr,
-              message: "Expected truthy, got #{inspect right}"
-          end
-        end)
+      no_warning(quote do
+        if right do
+          right
+        else
+          raise ExUnit.AssertionError,
+            expr: expr,
+            message: "Expected truthy, got #{inspect right}"
+        end
+      end)
 
     quote do
       right = unquote(right)
@@ -408,8 +408,8 @@ defmodule ExUnit.Assertions do
         {:ok, acc}
       {:_, _, context}, acc when is_atom(context) ->
         {:ok, acc}
-      {name, _, context}, acc when is_atom(name) and is_atom(context) ->
-        {:ok, [{name, [generated: true], context}|acc]}
+      {name, meta, context}, acc when is_atom(name) and is_atom(context) ->
+        {:ok, [{name, [generated: true] ++ meta, context} | acc]}
       node, acc ->
         {node, acc}
     end)

lib/ex_unit/test/ex_unit/assertions_test.exs

@@ -11,6 +11,16 @@ alias ExUnit.AssertionsTest.Value
 defmodule ExUnit.AssertionsTest do
   use ExUnit.Case, async: true
 
+  defmacrop assert_ok(arg) do
+    quote do
+      assert {:ok, val} = ok(unquote(arg))
+    end
+  end
+
+  test "assert inside macro" do
+    assert_ok 42
+  end
+
   test "assert with true value" do
     true = assert Value.truthy
   end