Build custom database in test

Makefile

@@ -6,24 +6,16 @@ CFLAGS = -std=c99 -g -Wall -Werror
 CPPFLAGS = -I$(ERL_EI_INCLUDE)
 LDFLAGS = -L$(ERL_EI_LIB)
 LDLIBS = -lpthread -lei -lm -lmagic
-BEAM_FILES = _build/
 PRIV = priv/
 RM = rm -Rf
 
-# Unit test custom magic file
-
-MAGIC = file
-
-all: priv/apprentice test/elixir.mgc
-
-test/%.mgc: test/%
-	cd test; file -C -m ../$^
+all: priv/apprentice
 
 priv/apprentice: src/apprentice.c
 	mkdir -p priv
 	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
 
 clean:
-	$(RM) $(PRIV) $(BEAM_FILES) test/*.mgc
+	$(RM) $(PRIV)
 
 .PHONY: clean

test/gen_magic/gen_magic_test.exs

@@ -42,7 +42,9 @@ defmodule GenMagicTest do
   end
 
   test "Custom database file recognises Elixir files" do
-    database = absolute_path("test/elixir.mgc")
+    database = absolute_path("elixir.mgc")
+    on_exit(fn() -> File.rm(database) end)
+    {_, 0} = System.cmd("file", ["-C", "-m", absolute_path("test/elixir")])
     {:ok, pid} = GenMagic.Server.start_link(database_patterns: [database])
     path = absolute_path("mix.exs")
     assert {:ok, %Result{} = result} = GenMagic.Server.perform(pid, path)