Metadata in logger for 1.15 Elixir

config/config.exs

@@ -0,0 +1,3 @@
+import Config
+
+import_config "#{config_env()}.exs"

config/test.exs

@@ -0,0 +1,5 @@
+import Config
+
+config :logger, :default_formatter, metadata: [:key_new]
+
+config :logger, :console, metadata: [:key_old]

lib/credo/check/warning/missed_metadata_key_in_logger_config.ex

@@ -155,12 +155,20 @@ defmodule Credo.Check.Warning.MissedMetadataKeyInLoggerConfig do
   end
 
   defp find_metadata_keys(params) do
-    metadata_keys = Params.get(params, :metadata_keys, __MODULE__)
+    with [] <- Params.get(params, :metadata_keys, __MODULE__) do
+      find_metadata_from_config()
+    end
+  end
 
-    if metadata_keys == [] do
-      :logger |> Application.get_env(:console, []) |> Keyword.get(:metadata, [])
+  defp find_metadata_from_config do
+    with true <- Version.match?(System.version(), "~> 1.15"),
+         {:ok, options} <- Application.fetch_env(:logger, :default_formatter) do
+      Keyword.get(options, :metadata, [])
     else
-      metadata_keys
+      _ ->
+        :logger
+        |> Application.get_env(:console, [])
+        |> Keyword.get(:metadata, [])
     end
   end
 end

test/credo/check/warning/missed_metadata_key_in_logger_config_test.exs

@@ -41,6 +41,68 @@ defmodule Credo.Check.Warning.MissedMetadataKeyInLoggerConfigTest do
     end
   end
 
+  describe "Version-specific" do
+    for fun <- @logger_functions do
+      if Version.match?(System.version(), "~> 1.15") do
+        test "it should report a violation when Logger.#{fun}/2 is used with metadata not present in default_formatter but present in console in ~> 1.15 Elixir" do
+          """
+          defmodule CredoSampleModule do
+            def some_function(parameter1, parameter2) do
+              var_1 = "Hello world"
+              Logger.#{unquote(fun)}("The module: #\{var1\}", key_old: "value")
+            end
+          end
+          """
+          |> to_source_file
+          |> run_check(@described_check)
+          |> assert_issue()
+        end
+
+        test "it should NOT report a violation when Logger.#{fun}/2 is used with metadata present in default_formatter in ~> 1.15 Elixir" do
+          """
+          defmodule CredoSampleModule do
+            def some_function(parameter1, parameter2) do
+              var_1 = "Hello world"
+              Logger.#{unquote(fun)}("The module: #\{var1\}", key_new: "value")
+            end
+          end
+          """
+          |> to_source_file
+          |> run_check(@described_check)
+          |> refute_issues()
+        end
+      else
+        test "it should NOT report a violation when Logger.#{fun}/2 is used with metadata not present in default_formatter but present in console in <= 1.15 Elixir" do
+          """
+          defmodule CredoSampleModule do
+            def some_function(parameter1, parameter2) do
+              var_1 = "Hello world"
+              Logger.#{unquote(fun)}("The module: #\{var1\}", key_old: "value")
+            end
+          end
+          """
+          |> to_source_file
+          |> run_check(@described_check)
+          |> refute_issues()
+        end
+
+        test "it should report a violation when Logger.#{fun}/2 is used with metadata present in default_formatter in <= 1.15 Elixir" do
+          """
+          defmodule CredoSampleModule do
+            def some_function(parameter1, parameter2) do
+              var_1 = "Hello world"
+              Logger.#{unquote(fun)}("The module: #\{var1\}", key_new: "value")
+            end
+          end
+          """
+          |> to_source_file
+          |> run_check(@described_check)
+          |> assert_issue()
+        end
+      end
+    end
+  end
+
   for fun <- @logger_functions do
     test "it should report a violation when Logger.#{fun}/2 is used with disallowed metadata" do
       """