fix: prevent zombie mix processes from integration tests

Author: zachallaun

priv/zombie_killer

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+# Modified version of port wrapper that supports sending a
+# string to the wrapper program's stdin
+
+# Run the program in the background, sending
+# $ZOMBIE_KILLER_INPUT as stdin
+echo -e "$ZOMBIE_KILLER_INPUT" | exec "$@" &
+program_pid=$!
+
+# Silence warnings from here on
+exec >/dev/null 2>&1
+
+# Read from stdin in the background and kill process
+# when stdin closes
+(
+  while read; do :; done
+  kill -KILL $program_pid
+) <&0 &
+stdin_monitor_pid=$!
+
+# Clean up
+wait $program_pid
+ret=$?
+kill -KILL $stdin_monitor_pid
+exit $ret

test/support/integration.ex

@@ -61,8 +61,9 @@ defmodule Mneme.Integration do
     File.write!(file_path, test.test_code)
 
     test_command = """
-    echo "#{test.test_input}" | \
-      CI=false mix test #{file_path} --seed 0 \
+    ZOMBIE_KILLER_INPUT=#{inspect(test.test_input)} \
+      CI=false \
+      #{zombie_killer()} mix test #{file_path} --seed 0 \
     """
 
     test_command =
@@ -108,6 +109,10 @@ defmodule Mneme.Integration do
     end
   end
 
+  defp zombie_killer do
+    :mneme |> :code.priv_dir() |> Path.join("zombie_killer")
+  end
+
   defp debug_setup(nil, _), do: :ok
 
   defp debug_setup("", test) do