Only print metadata of known types, closes #9814

Author: josevalim

lib/logger/lib/logger/formatter.ex

@@ -168,22 +168,42 @@ defmodule Logger.Formatter do
   defp levelpad(:warn), do: " "
   defp levelpad(:error), do: ""
 
-  defp metadata([{:report_cb, _} | metadata]), do: metadata(metadata)
-  defp metadata([{:time, _} | metadata]), do: metadata(metadata)
-  defp metadata([{:gl, _} | metadata]), do: metadata(metadata)
-  defp metadata([{:crash_reason, _} | metadata]), do: metadata(metadata)
-  defp metadata([{:ancestors, _} | metadata]), do: metadata(metadata)
-  defp metadata([{:callers, _} | metadata]), do: metadata(metadata)
-  defp metadata([{_, nil} | metadata]), do: metadata(metadata)
-
   defp metadata([{key, value} | metadata]) do
-    [to_string(key), ?=, metadata(key, value), ?\s | metadata(metadata)]
+    if formatted = metadata(key, value) do
+      [to_string(key), ?=, formatted, ?\s | metadata(metadata)]
+    else
+      metadata(metadata)
+    end
   end
 
   defp metadata([]) do
     []
   end
 
+  defp metadata(:time, _), do: nil
+  defp metadata(:gl, _), do: nil
+
+  defp metadata(_, nil), do: nil
+  defp metadata(_, string) when is_binary(string), do: string
+  defp metadata(_, integer) when is_integer(integer), do: Integer.to_string(integer)
+  defp metadata(_, float) when is_float(float), do: Float.to_string(float)
+  defp metadata(_, pid) when is_pid(pid), do: :erlang.pid_to_list(pid)
+
+  defp metadata(_, atom) when is_atom(atom) do
+    case Atom.to_string(atom) do
+      "Elixir." <> rest -> rest
+      "nil" -> ""
+      binary -> binary
+    end
+  end
+
+  defp metadata(_, ref) when is_reference(ref) do
+    '#Ref' ++ rest = :erlang.ref_to_list(ref)
+    rest
+  end
+
+  defp metadata(:file, file) when is_list(file), do: file
+
   defp metadata(:domain, [head | tail]) when is_atom(head) do
     Enum.map_intersperse([head | tail], ?., &Atom.to_string/1)
   end
@@ -198,22 +218,5 @@ defmodule Logger.Formatter do
     Exception.format_mfa(mod, fun, arity)
   end
 
-  defp metadata(_, pid) when is_pid(pid) do
-    :erlang.pid_to_list(pid)
-  end
-
-  defp metadata(_, ref) when is_reference(ref) do
-    '#Ref' ++ rest = :erlang.ref_to_list(ref)
-    rest
-  end
-
-  defp metadata(_, atom) when is_atom(atom) do
-    case Atom.to_string(atom) do
-      "Elixir." <> rest -> rest
-      "nil" -> ""
-      binary -> binary
-    end
-  end
-
-  defp metadata(_, other), do: to_string(other)
+  defp metadata(_, _), do: nil
 end

lib/logger/lib/logger/handler.ex

@@ -90,6 +90,7 @@ defmodule Logger.Handler do
             :ok
 
           {message, %{gl: gl} = metadata} ->
+            timestamp = Map.get_lazy(metadata, :time, fn -> :os.system_time(:microsecond) end)
             metadata = erlang_metadata_to_elixir_metadata(metadata)
             %{truncate: truncate, utc_log: utc_log?} = config
 

lib/logger/test/logger/formatter_test.exs

@@ -77,9 +77,9 @@ defmodule Logger.FormatterTest do
              "2014-12-30 12:06:30.100"
   end
 
-  test "format discards callers/ancestors/crash_reason" do
+  test "format discards unknown formats" do
     compiled = compile("$metadata $message")
-    metadata = [callers: :discard, ancestors: :discard, crash_reason: :discard, foo: :bar]
+    metadata = [ancestors: [self()], crash_reason: {:some, :tuple}, foo: :bar]
 
     assert format(compiled, :error, "hello", nil, metadata) ==
              [["foo", 61, "bar", 32], " ", "hello"]