Test to verify that metadata for Tesla.Middleware is kept for each sl…

…ice of the response.

config/config.exs

@@ -1,3 +1,3 @@
 import Config
 
-config :logger, :default_formatter, metadata: ~w(bar baz foo)a
+config :logger, :default_formatter, metadata: ~w(bar baz foo request_id)a

test/tesla/middleware/meta_logger_test.exs

@@ -1,5 +1,7 @@
 defmodule Tesla.Middleware.MetaLoggerTest do
-  use ExUnit.Case, async: true
+  use ExUnit.Case, async: false
+
+  require Logger
 
   import ExUnit.CaptureLog
 
@@ -227,6 +229,23 @@ defmodule Tesla.Middleware.MetaLoggerTest do
       assert logs =~ "[debug] [#{inspect(Subject)}] #{String.duplicate("b", 100)}\n"
     end
 
+    test "when the max entry length is given and the logs are split, the metadata is captured with each line" do
+      Logger.metadata(request_id: "123123123")
+
+      body = String.duplicate("x", 100)
+
+      log_lines =
+        capture_log(fn ->
+          FakeClient.post("/huge-response", body, opts: [max_entry_length: 10])
+        end)
+        |> String.split("\n\n")
+
+      log_lines
+      |> Enum.each(fn log_line ->
+        assert log_line =~ "request_id=123123123"
+      end)
+    end
+
     test "when response is an error, logs the response with error log level" do
       logs = capture_log(fn -> FakeClient.get("/error") end)