Don't bother printing the filename in error messages, it is always redundant

Whenever we have the filename we ALWAYS have the module name, which is
effectively just as useful and already printed.

src/error_logger_lager_h.erl

@@ -262,11 +262,11 @@ format_mfa({M, F, A}) when is_list(A) ->
 format_mfa({M, F, A}) when is_integer(A) ->
     io_lib:format("~w:~w/~w", [M, F, A]);
 format_mfa({M, F, A, Props}) when is_list(Props) ->
-    case {proplists:get_value(file, Props), proplists:get_value(line, Props)} of
-        {undefined, undefined} ->
+    case proplists:get_value(line, Props) of
+        undefined ->
             format_mfa({M, F, A});
-        {File, Line} ->
-            [format_mfa({M, F, A}), io_lib:format(" (~s:~w)", [File, Line])]
+        Line ->
+            [format_mfa({M, F, A}), io_lib:format(" line ~w", [Line])]
     end;
 format_mfa(Other) ->
     io_lib:format("~w", [Other]).

test/lager_test_backend.erl

@@ -247,13 +247,13 @@ crash(Type) ->
     _ = gen_event:which_handlers(error_logger),
     ok.
 
-test_body(Expected, Actual, File) ->
+test_body(Expected, Actual) ->
     case has_line_numbers() of
         true ->
             FileLine = string:substr(Actual, length(Expected)+1),
             Body = string:substr(Actual, 1, length(Expected)),
             ?assertEqual(Expected, Body),
-            ?assertEqual(File, string:substr(FileLine, 3, length(File)));
+            ?assertEqual(" line ", string:substr(FileLine, 1, 6));
         false ->
             ?assertEqual(Expected, Actual)
     end.
@@ -294,7 +294,6 @@ error_logger_redirect_crash_test_() ->
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: bad return value: bleh", [Pid])),
                         ?assertEqual(Expected, lists:flatten(Msg))
-                        %test_body(Expected, lists:flatten(msg), "test/crash.erl")
                 end
             },
             {"bad return value with string",
@@ -312,7 +311,7 @@ error_logger_redirect_crash_test_() ->
                         crash(case_clause),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: no case clause matching {} in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"case clause string",
@@ -321,7 +320,7 @@ error_logger_redirect_crash_test_() ->
                         crash(case_clause_string),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: no case clause matching \"crash\" in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"function clause",
@@ -330,7 +329,7 @@ error_logger_redirect_crash_test_() ->
                         crash(function_clause),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: no function clause matching crash:function({})", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"if clause",
@@ -339,7 +338,7 @@ error_logger_redirect_crash_test_() ->
                         crash(if_clause),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: no true branch found while evaluating if expression in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"try clause",
@@ -348,7 +347,7 @@ error_logger_redirect_crash_test_() ->
                         crash(try_clause),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: no try clause matching [] in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"undefined function",
@@ -357,7 +356,7 @@ error_logger_redirect_crash_test_() ->
                         crash(undef),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: call to undefined function crash:booger/0 from crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"bad math",
@@ -366,7 +365,7 @@ error_logger_redirect_crash_test_() ->
                         crash(badarith),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: bad arithmetic expression in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"bad match",
@@ -375,7 +374,7 @@ error_logger_redirect_crash_test_() ->
                         crash(badmatch),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: no match of right hand value {} in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"bad arity",
@@ -384,7 +383,7 @@ error_logger_redirect_crash_test_() ->
                         crash(badarity),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: fun called with wrong arity of 1 instead of 3 in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"bad arg1",
@@ -393,7 +392,7 @@ error_logger_redirect_crash_test_() ->
                         crash(badarg1),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: bad argument in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"bad arg2",
@@ -402,7 +401,7 @@ error_logger_redirect_crash_test_() ->
                         crash(badarg2),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: bad argument in call to erlang:iolist_to_binary([\"foo\",bar]) in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"noproc",
@@ -420,7 +419,7 @@ error_logger_redirect_crash_test_() ->
                         crash(badfun),
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~w gen_server crash terminated with reason: bad function booger in crash:handle_call/3", [Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/crash.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             }
 
@@ -718,7 +717,7 @@ error_logger_redirect_test_() ->
                         {_, _, Msg} = pop(),
                         Expected = lists:flatten(io_lib:format("[error] ~p CRASH REPORT Process ~p with 0 neighbours crashed with reason: no function clause matching special_process:foo(bar)",
                                 [Pid, Pid])),
-                        test_body(Expected, lists:flatten(Msg), "test/special_process.erl")
+                        test_body(Expected, lists:flatten(Msg))
                 end
             },
             {"messages should not be generated if they don't satisfy the threshold",