From cb075aa2469273f606896c4c2036c1a6ca7d951d Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Tue, 26 Mar 2024 15:07:10 -0500
Subject: [PATCH 01/10] refactor Airbrake.Payload functions

---
 lib/airbrake/payload.ex | 49 +++++++++++++----------------------------
 1 file changed, 15 insertions(+), 34 deletions(-)

diff --git a/lib/airbrake/payload.ex b/lib/airbrake/payload.ex
index 8895b7e..1b8d0b1 100644
--- a/lib/airbrake/payload.ex
+++ b/lib/airbrake/payload.ex
@@ -28,34 +28,25 @@ defmodule Airbrake.Payload do
   end
 
   def new(exception, stacktrace, options) when is_list(exception) do
-    %__MODULE__{}
-    |> add_error(
-      exception,
-      stacktrace,
-      Keyword.get(options, :context),
-      Keyword.get(options, :env),
-      Keyword.get(options, :params),
-      Keyword.get(options, :session)
-    )
+    %__MODULE__{
+      errors: [build_error(exception, stacktrace)],
+      context: Map.merge(%{environment: env(), hostname: hostname()}, get_option(options, :context) || %{}),
+      environment: options |> get_option(:env) |> filter_environment(),
+      params: options |> get_option(:params) |> filter_parameters(),
+      session: get_option(options, :session)
+    }
   end
 
-  defp add_error(payload, exception, stacktrace, context, env, params, session) do
-    payload
-    |> add_exception_info(exception, stacktrace)
-    |> add_context(context)
-    |> add_env(env)
-    |> add_params(params)
-    |> add_session(session)
+  defp get_option(options, key) do
+    Keyword.get(options, key)
   end
 
-  defp add_exception_info(payload, exception, stacktrace) do
-    error = %{
+  defp build_error(exception, stacktrace) do
+    %{
       type: exception[:type],
       message: exception[:message],
       backtrace: Backtrace.from_stacktrace(stacktrace)
     }
-
-    Map.put(payload, :errors, [error])
   end
 
   defp env do
@@ -72,22 +63,12 @@ defmodule Airbrake.Payload do
     System.get_env("HOST") || to_string(elem(:inet.gethostname(), 1))
   end
 
-  defp add_context(payload, context) do
-    context = Map.merge(%{environment: env(), hostname: hostname()}, context || %{})
-    Map.put(payload, :context, context)
-  end
-
-  defp add_env(payload, nil), do: payload
-  defp add_env(payload, env), do: Map.put(payload, :environment, filter_environment(env))
-
-  defp add_params(payload, nil), do: payload
-  defp add_params(payload, params), do: Map.put(payload, :params, filter_parameters(params))
-
-  defp add_session(payload, nil), do: payload
-  defp add_session(payload, session), do: Map.put(payload, :session, session)
-
   defp filter_parameters(params), do: filter(params, :filter_parameters)
 
+  defp filter_environment(nil) do
+    nil
+  end
+
   defp filter_environment(env) do
     if Map.has_key?(env, "headers"),
       do: Map.update!(env, "headers", &filter(&1, :filter_headers)),

From 5621f73bc554f7d71bb61e2efc31e7413e214680 Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Tue, 26 Mar 2024 15:12:24 -0500
Subject: [PATCH 02/10] refactor Airbrake.Payload functions

---
 lib/airbrake/payload.ex | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/lib/airbrake/payload.ex b/lib/airbrake/payload.ex
index 1b8d0b1..ac5085d 100644
--- a/lib/airbrake/payload.ex
+++ b/lib/airbrake/payload.ex
@@ -30,17 +30,13 @@ defmodule Airbrake.Payload do
   def new(exception, stacktrace, options) when is_list(exception) do
     %__MODULE__{
       errors: [build_error(exception, stacktrace)],
-      context: Map.merge(%{environment: env(), hostname: hostname()}, get_option(options, :context) || %{}),
-      environment: options |> get_option(:env) |> filter_environment(),
-      params: options |> get_option(:params) |> filter_parameters(),
-      session: get_option(options, :session)
+      context: build(:context, options),
+      environment: build(:environment, options),
+      params: build(:params, options),
+      session: build(:session, options)
     }
   end
 
-  defp get_option(options, key) do
-    Keyword.get(options, key)
-  end
-
   defp build_error(exception, stacktrace) do
     %{
       type: exception[:type],
@@ -49,6 +45,25 @@ defmodule Airbrake.Payload do
     }
   end
 
+  defp build(:context, options) do
+    Map.merge(
+      %{environment: env(), hostname: hostname()},
+      Keyword.get(options, :context, %{})
+    )
+  end
+
+  defp build(:environment, options) do
+    options |> Keyword.get(:env) |> filter_environment()
+  end
+
+  defp build(:params, options) do
+    options |> Keyword.get(:params) |> filter_parameters()
+  end
+
+  defp build(key, options) do
+    Keyword.get(options, key)
+  end
+
   defp env do
     case Application.get_env(:airbrake_client, :environment) do
       nil -> hostname()

From 469f0c13451329ad588ef751187fa58f8298cab8 Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Tue, 26 Mar 2024 15:17:00 -0500
Subject: [PATCH 03/10] rename a function

---
 lib/airbrake/payload.ex |  2 +-
 lib/airbrake/worker.ex  | 20 ++++++++++----------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/airbrake/payload.ex b/lib/airbrake/payload.ex
index ac5085d..a62cfc1 100644
--- a/lib/airbrake/payload.ex
+++ b/lib/airbrake/payload.ex
@@ -91,6 +91,6 @@ defmodule Airbrake.Payload do
   end
 
   defp filter(map, attributes_key) do
-    Utils.filter(map, Airbrake.Worker.get_env(attributes_key))
+    Utils.filter(map, Airbrake.Worker.get_config(attributes_key))
   end
 end
diff --git a/lib/airbrake/worker.ex b/lib/airbrake/worker.ex
index e6298d5..8f8f282 100644
--- a/lib/airbrake/worker.ex
+++ b/lib/airbrake/worker.ex
@@ -108,7 +108,7 @@ defmodule Airbrake.Worker do
   end
 
   defp build_options(current_options) do
-    case get_env(:options) do
+    case get_config(:options) do
       {mod, fun, 1} ->
         apply(mod, fun, [current_options])
 
@@ -126,7 +126,7 @@ defmodule Airbrake.Worker do
   end
 
   defp ignore?(type: type, message: message) do
-    ignore?(get_env(:ignore), type, message)
+    ignore?(get_config(:ignore), type, message)
   end
 
   defp ignore?(nil, _type, _message), do: false
@@ -139,20 +139,20 @@ defmodule Airbrake.Worker do
 
   defp notify_url do
     Path.join([
-      get_env(:host, @default_host),
+      get_config(:host, @default_host),
       "api/v3/projects",
-      :project_id |> get_env() |> to_string(),
-      "notices?key=#{get_env(:api_key)}"
+      :project_id |> get_config() |> to_string(),
+      "notices?key=#{get_config(:api_key)}"
     ])
   end
 
-  def get_env(key, default \\ nil) do
+  def get_config(key, default \\ nil) do
     :airbrake_client
     |> Application.get_env(key, default)
-    |> process_env()
+    |> process_config()
   end
 
-  defp process_env({:system, key, default}), do: System.get_env(key) || default
-  defp process_env({:system, key}), do: System.get_env(key)
-  defp process_env(value), do: value
+  defp process_config({:system, key, default}), do: System.get_env(key) || default
+  defp process_config({:system, key}), do: System.get_env(key)
+  defp process_config(value), do: value
 end

From 3fb38f877127bbf1a5bc6d6439afebc237e49a5d Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Mon, 1 Apr 2024 12:55:23 -0500
Subject: [PATCH 04/10] extract config from config/dev.exs to
 config/runtime.exs

---
 config/dev.exs     |  5 ++---
 config/runtime.exs | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 3 deletions(-)
 create mode 100644 config/runtime.exs

diff --git a/config/dev.exs b/config/dev.exs
index db78276..c1a11b6 100644
--- a/config/dev.exs
+++ b/config/dev.exs
@@ -1,8 +1,7 @@
 import Config
 
 # These settings can be used on the iex console.
+# More are set in `config/runtime.exs`.
 config :airbrake_client,
-  api_key: {:system, "AIRBRAKE_API_KEY"},
-  project_id: {:system, "AIRBRAKE_PROJECT_ID"},
-  host: {:system, "AIRBRAKE_HOST", "https://api.airbrake.io"},
+  session: :include_logger_metadata,
   private: [http_adapter: HTTPoison]
diff --git a/config/runtime.exs b/config/runtime.exs
new file mode 100644
index 0000000..bb33950
--- /dev/null
+++ b/config/runtime.exs
@@ -0,0 +1,15 @@
+import Config
+
+case config_env() do
+  :dev ->
+    config :airbrake_client,
+      api_key: System.get_env("AIRBRAKE_API_KEY"),
+      project_id: System.get_env("AIRBRAKE_PROJECT_ID"),
+      host: System.get_env("AIRBRAKE_HOST", "https://api.airbrake.io")
+
+  :test ->
+    nil
+
+  :prod ->
+    nil
+end

From bc68e5dc0137179b24cbfa74b05dc0e89c923390 Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Tue, 26 Mar 2024 15:25:39 -0500
Subject: [PATCH 05/10] extract Airbrake.Config

---
 lib/airbrake/config.ex  | 47 +++++++++++++++++++++++++++++++++++++++++
 lib/airbrake/payload.ex | 22 +++++--------------
 lib/airbrake/worker.ex  | 24 +++++++++------------
 test/support/mocks.ex   |  1 +
 4 files changed, 63 insertions(+), 31 deletions(-)
 create mode 100644 lib/airbrake/config.ex

diff --git a/lib/airbrake/config.ex b/lib/airbrake/config.ex
new file mode 100644
index 0000000..bb60b7f
--- /dev/null
+++ b/lib/airbrake/config.ex
@@ -0,0 +1,47 @@
+defmodule Airbrake.Config do
+  @moduledoc false
+
+  defmodule Behaviour do
+    @moduledoc false
+
+    @callback get(atom()) :: any()
+
+    @callback get(atom(), any()) :: any()
+
+    @callback env :: String.t()
+
+    @callback hostname :: String.t()
+  end
+
+  @behaviour Airbrake.Config.Behaviour
+
+  # Gets a value from the `:airbrake_client` config.
+  @impl Airbrake.Config.Behaviour
+  def get(key, default \\ nil) do
+    :airbrake_client
+    |> Application.get_env(key, default)
+    |> resolve()
+  end
+
+  # Returns the name of the environment.
+  @impl Airbrake.Config.Behaviour
+  def env do
+    case Application.get_env(:airbrake_client, :environment) do
+      nil -> hostname()
+      {:system, var} -> System.get_env(var, hostname())
+      atom_env when is_atom(atom_env) -> to_string(atom_env)
+      str_env when is_binary(str_env) -> str_env
+      fun_env when is_function(fun_env) -> fun_env.()
+    end
+  end
+
+  # Returns a hostname.
+  @impl Airbrake.Config.Behaviour
+  def hostname do
+    System.get_env("HOST") || to_string(elem(:inet.gethostname(), 1))
+  end
+
+  defp resolve({:system, key, default}), do: System.get_env(key) || default
+  defp resolve({:system, key}), do: System.get_env(key)
+  defp resolve(value), do: value
+end
diff --git a/lib/airbrake/payload.ex b/lib/airbrake/payload.ex
index a62cfc1..1d55be8 100644
--- a/lib/airbrake/payload.ex
+++ b/lib/airbrake/payload.ex
@@ -1,6 +1,8 @@
 defmodule Airbrake.Payload do
   @moduledoc false
 
+  alias Airbrake.Config
+
   @notifier_info %{
     name: "Airbrake Client",
     version: Airbrake.Mixfile.project()[:version],
@@ -47,7 +49,7 @@ defmodule Airbrake.Payload do
 
   defp build(:context, options) do
     Map.merge(
-      %{environment: env(), hostname: hostname()},
+      %{environment: Config.env(), hostname: Config.hostname()},
       Keyword.get(options, :context, %{})
     )
   end
@@ -64,20 +66,6 @@ defmodule Airbrake.Payload do
     Keyword.get(options, key)
   end
 
-  defp env do
-    case Application.get_env(:airbrake_client, :environment) do
-      nil -> hostname()
-      {:system, var} -> System.get_env(var) || hostname()
-      atom_env when is_atom(atom_env) -> to_string(atom_env)
-      str_env when is_binary(str_env) -> str_env
-      fun_env when is_function(fun_env) -> fun_env.()
-    end
-  end
-
-  def hostname do
-    System.get_env("HOST") || to_string(elem(:inet.gethostname(), 1))
-  end
-
   defp filter_parameters(params), do: filter(params, :filter_parameters)
 
   defp filter_environment(nil) do
@@ -90,7 +78,7 @@ defmodule Airbrake.Payload do
       else: env
   end
 
-  defp filter(map, attributes_key) do
-    Utils.filter(map, Airbrake.Worker.get_config(attributes_key))
+  defp filter(map, config_key) do
+    Utils.filter(map, Config.get(config_key))
   end
 end
diff --git a/lib/airbrake/worker.ex b/lib/airbrake/worker.ex
index 8f8f282..3c6b984 100644
--- a/lib/airbrake/worker.ex
+++ b/lib/airbrake/worker.ex
@@ -7,6 +7,8 @@ defmodule Airbrake.Worker do
     defstruct refs: %{}, last_exception: nil
   end
 
+  alias Airbrake.Config
+
   @name __MODULE__
   @request_headers [{"Content-Type", "application/json"}]
   @default_host "https://api.airbrake.io"
@@ -108,7 +110,7 @@ defmodule Airbrake.Worker do
   end
 
   defp build_options(current_options) do
-    case get_config(:options) do
+    case Config.get(:options) do
       {mod, fun, 1} ->
         apply(mod, fun, [current_options])
 
@@ -126,7 +128,7 @@ defmodule Airbrake.Worker do
   end
 
   defp ignore?(type: type, message: message) do
-    ignore?(get_config(:ignore), type, message)
+    ignore?(Config.get(:ignore), type, message)
   end
 
   defp ignore?(nil, _type, _message), do: false
@@ -139,20 +141,14 @@ defmodule Airbrake.Worker do
 
   defp notify_url do
     Path.join([
-      get_config(:host, @default_host),
+      Config.get(:host, @default_host),
       "api/v3/projects",
-      :project_id |> get_config() |> to_string(),
-      "notices?key=#{get_config(:api_key)}"
+      :project_id |> Config.get() |> to_string(),
+      "notices?key=#{Config.get(:api_key)}"
     ])
   end
 
-  def get_config(key, default \\ nil) do
-    :airbrake_client
-    |> Application.get_env(key, default)
-    |> process_config()
-  end
-
-  defp process_config({:system, key, default}), do: System.get_env(key) || default
-  defp process_config({:system, key}), do: System.get_env(key)
-  defp process_config(value), do: value
+  @deprecated "Use Airbrake.Config.get/2 instead."
+  def get_env(key, default \\ nil),
+    do: Config.get(key, default)
 end
diff --git a/test/support/mocks.ex b/test/support/mocks.ex
index a47b665..f242119 100644
--- a/test/support/mocks.ex
+++ b/test/support/mocks.ex
@@ -1 +1,2 @@
 Mox.defmock(Airbrake.HTTPMock, for: HTTPoison.Base)
+Mox.defmock(MockConfig, for: Airbrake.Config.Behaviour)

From f11ec158ef0da65d166da4df434d23f203725f1d Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Wed, 27 Mar 2024 11:39:24 -0500
Subject: [PATCH 06/10] bump dialyxir to ~> 1.4

---
 mix.exs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mix.exs b/mix.exs
index f2585c4..31bd295 100644
--- a/mix.exs
+++ b/mix.exs
@@ -59,9 +59,7 @@ defmodule Airbrake.Mixfile do
   defp deps do
     [
       {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
-      # 1.4 is not compilable with Elixir <1.12.
-      # For test CI, we just need to _compile_ dialyxir on earlier versions.
-      {:dialyxir, "~> 1.3.0", only: [:dev, :test], runtime: false},
+      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false},
       {:ex_doc, "~> 0.30", only: [:dev, :test]},
       {:excoveralls, "~> 0.18", only: :test},
       {:httpoison, "~> 1.0 or ~> 2.0"},

From 7134926df96360663cb09d49c6d676f737f7236e Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Wed, 27 Mar 2024 14:18:06 -0500
Subject: [PATCH 07/10] extract Airbrake.Payload.Builder with better tests

---
 config/test.exs                        |   3 +-
 lib/airbrake/payload.ex                |  66 ++-----
 lib/airbrake/payload/builder.ex        |  76 ++++++++
 test/airbrake/payload/builder_test.exs | 229 +++++++++++++++++++++++++
 test/airbrake/payload_test.exs         |  11 +-
 5 files changed, 323 insertions(+), 62 deletions(-)
 create mode 100644 lib/airbrake/payload/builder.ex
 create mode 100644 test/airbrake/payload/builder_test.exs

diff --git a/config/test.exs b/config/test.exs
index d78227a..54db463 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -4,4 +4,5 @@ import Config
 config :airbrake_client,
   api_key: "TESTING_API_KEY",
   project_id: 8_675_309,
-  private: [http_adapter: Airbrake.HTTPMock]
+  private: [http_adapter: Airbrake.HTTPMock],
+  filter_parameters: ["password"]
diff --git a/lib/airbrake/payload.ex b/lib/airbrake/payload.ex
index 1d55be8..0e29028 100644
--- a/lib/airbrake/payload.ex
+++ b/lib/airbrake/payload.ex
@@ -1,7 +1,7 @@
 defmodule Airbrake.Payload do
   @moduledoc false
 
-  alias Airbrake.Config
+  alias Airbrake.Payload.Builder
 
   @notifier_info %{
     name: "Airbrake Client",
@@ -20,65 +20,19 @@ defmodule Airbrake.Payload do
             params: nil,
             session: nil
 
-  alias Airbrake.Payload.Backtrace
-  alias Airbrake.Utils
+  def new(exception, stacktrace, opts \\ [])
 
-  def new(exception, stacktrace, options \\ [])
-
-  def new(%{__exception__: true} = exception, stacktrace, options) do
-    new(Airbrake.Worker.exception_info(exception), stacktrace, options)
+  def new(%{__exception__: true} = exception, stacktrace, opts) do
+    new(Airbrake.Worker.exception_info(exception), stacktrace, opts)
   end
 
-  def new(exception, stacktrace, options) when is_list(exception) do
+  def new(exception, stacktrace, opts) when is_list(exception) do
     %__MODULE__{
-      errors: [build_error(exception, stacktrace)],
-      context: build(:context, options),
-      environment: build(:environment, options),
-      params: build(:params, options),
-      session: build(:session, options)
+      errors: [Builder.build_error(exception, stacktrace)],
+      context: Builder.build(:context, opts),
+      environment: Builder.build(:environment, opts),
+      params: Builder.build(:params, opts),
+      session: Builder.build(:session, opts)
     }
   end
-
-  defp build_error(exception, stacktrace) do
-    %{
-      type: exception[:type],
-      message: exception[:message],
-      backtrace: Backtrace.from_stacktrace(stacktrace)
-    }
-  end
-
-  defp build(:context, options) do
-    Map.merge(
-      %{environment: Config.env(), hostname: Config.hostname()},
-      Keyword.get(options, :context, %{})
-    )
-  end
-
-  defp build(:environment, options) do
-    options |> Keyword.get(:env) |> filter_environment()
-  end
-
-  defp build(:params, options) do
-    options |> Keyword.get(:params) |> filter_parameters()
-  end
-
-  defp build(key, options) do
-    Keyword.get(options, key)
-  end
-
-  defp filter_parameters(params), do: filter(params, :filter_parameters)
-
-  defp filter_environment(nil) do
-    nil
-  end
-
-  defp filter_environment(env) do
-    if Map.has_key?(env, "headers"),
-      do: Map.update!(env, "headers", &filter(&1, :filter_headers)),
-      else: env
-  end
-
-  defp filter(map, config_key) do
-    Utils.filter(map, Config.get(config_key))
-  end
 end
diff --git a/lib/airbrake/payload/builder.ex b/lib/airbrake/payload/builder.ex
new file mode 100644
index 0000000..6e6053a
--- /dev/null
+++ b/lib/airbrake/payload/builder.ex
@@ -0,0 +1,76 @@
+defmodule Airbrake.Payload.Builder do
+  @moduledoc false
+
+  alias Airbrake.Payload.Backtrace
+  alias Airbrake.Utils
+
+  def build_error(exception, stacktrace) do
+    %{
+      type: exception[:type],
+      message: exception[:message],
+      backtrace: Backtrace.from_stacktrace(stacktrace)
+    }
+  end
+
+  def build(:context, opts) do
+    config = get_config(opts)
+
+    Map.merge(
+      %{environment: config.env(), hostname: config.hostname()},
+      opts |> Keyword.get(:context, %{}) |> Enum.into(%{})
+    )
+  end
+
+  def build(:environment, opts) do
+    environment =
+      Keyword.get_lazy(opts, :environment, fn ->
+        Keyword.get(opts, :env)
+      end)
+
+    case environment do
+      nil -> nil
+      env -> env |> Enum.into(%{}) |> filter_environment(opts)
+    end
+  end
+
+  def build(:params, opts) do
+    case Keyword.get(opts, :params) do
+      nil -> nil
+      params -> params |> Enum.into(%{}) |> filter_parameters(opts)
+    end
+  end
+
+  def build(:session, opts) do
+    if Keyword.has_key?(opts, :session),
+      do: opts |> Keyword.get(:session) |> Enum.into(%{}),
+      else: nil
+  end
+
+  def filter_parameters(params, opts) do
+    filter_parameters = get_config(opts).get(:filter_parameters, [])
+
+    Utils.filter(params, filter_parameters)
+  end
+
+  def filter_environment(nil) do
+    nil
+  end
+
+  def filter_environment(environment, opts) do
+    filter_headers = get_config(opts).get(:filter_headers, [])
+
+    cond do
+      Map.has_key?(environment, "headers") ->
+        Map.update!(environment, "headers", &Utils.filter(&1, filter_headers))
+
+      Map.has_key?(environment, :headers) ->
+        Map.update!(environment, :headers, &Utils.filter(&1, filter_headers))
+
+      true ->
+        environment
+    end
+  end
+
+  defp get_config(opts),
+    do: Keyword.get(opts, :config, Airbrake.Config)
+end
diff --git a/test/airbrake/payload/builder_test.exs b/test/airbrake/payload/builder_test.exs
new file mode 100644
index 0000000..56077c9
--- /dev/null
+++ b/test/airbrake/payload/builder_test.exs
@@ -0,0 +1,229 @@
+defmodule Airbrake.Payload.BuilderTest do
+  use ExUnit.Case, async: true
+  use ExUnitProperties
+
+  import Mox
+
+  alias Airbrake.Payload.Builder
+
+  setup :verify_on_exit!
+
+  describe "build/1 :context" do
+    property "builds default/initial context using env and hostname from config" do
+      opts = [config: MockConfig]
+
+      check all env <- env(),
+                hostname <- hostname() do
+        MockConfig
+        |> stub(:env, fn -> env end)
+        |> stub(:hostname, fn -> hostname end)
+
+        assert Builder.build(:context, opts) == %{environment: env, hostname: hostname}
+      end
+    end
+
+    property "can add more context" do
+      check all env <- env(),
+                hostname <- hostname(),
+                foo <- one_of([integer(), string(:alphanumeric)]),
+                bar <- one_of([integer(), string(:alphanumeric)]) do
+        MockConfig
+        |> stub(:env, fn -> env end)
+        |> stub(:hostname, fn -> hostname end)
+
+        opts = [
+          config: MockConfig,
+          context: %{foo: foo, bar: bar}
+        ]
+
+        assert Builder.build(:context, opts) == %{
+                 environment: env,
+                 hostname: hostname,
+                 foo: foo,
+                 bar: bar
+               }
+      end
+    end
+
+    property "can add more context with keyword list" do
+      check all env <- env(),
+                hostname <- hostname(),
+                foo <- one_of([integer(), string(:alphanumeric)]),
+                bar <- one_of([integer(), string(:alphanumeric)]) do
+        MockConfig
+        |> stub(:env, fn -> env end)
+        |> stub(:hostname, fn -> hostname end)
+
+        opts = [
+          config: MockConfig,
+          context: [foo: foo, bar: bar]
+        ]
+
+        assert Builder.build(:context, opts) == %{
+                 environment: env,
+                 hostname: hostname,
+                 foo: foo,
+                 bar: bar
+               }
+      end
+    end
+
+    property "context in opts overwrites defaults" do
+      check all env <- env(),
+                hostname <- hostname(),
+                opts_env <- env(),
+                opts_hostname <- hostname(),
+                foo <- integer() do
+        MockConfig
+        |> stub(:env, fn -> env end)
+        |> stub(:hostname, fn -> hostname end)
+
+        opts = [
+          config: MockConfig,
+          context: %{foo: foo, environment: opts_env, hostname: opts_hostname}
+        ]
+
+        assert Builder.build(:context, opts) == %{
+                 environment: opts_env,
+                 hostname: opts_hostname,
+                 foo: foo
+               }
+      end
+    end
+  end
+
+  describe "build/1 :environment" do
+    test "returns nil if unspecified" do
+      opts = []
+
+      assert is_nil(Builder.build(:environment, opts))
+    end
+
+    property "returns value from opts" do
+      check all environment <- map_of(atom(:alphanumeric), string(:alphanumeric)) do
+        opts = [
+          environment: environment
+        ]
+
+        assert Builder.build(:environment, opts) == environment
+      end
+    end
+
+    property "can specify with deprecated :env key" do
+      check all environment <- map_of(atom(:alphanumeric), string(:alphanumeric)) do
+        opts = [
+          env: environment
+        ]
+
+        assert Builder.build(:environment, opts) == environment
+      end
+    end
+
+    property "returns keyword list from opts as map" do
+      check all environment <- keyword_of(string(:alphanumeric)) do
+        opts = [
+          environment: environment
+        ]
+
+        assert Builder.build(:environment, opts) == Map.new(environment)
+      end
+    end
+
+    property "filters headers" do
+      check all headers1 <- map_of(string_key(), string(:alphanumeric)),
+                headers2 <- map_of(string_key(), string(:alphanumeric)),
+                headers = Map.merge(headers1, headers2) do
+        # filter keys in headers1
+        stub(MockConfig, :get, fn :filter_headers, _ -> Map.keys(headers1) end)
+
+        opts = [
+          config: MockConfig,
+          environment: %{headers: headers}
+        ]
+
+        assert %{headers: filtered_headers} = Builder.build(:environment, opts)
+
+        assert filtered_headers
+               |> Map.take(Map.keys(headers1))
+               |> Map.values()
+               |> Enum.all?(&(&1 == "[FILTERED]"))
+
+        assert filtered_headers |> Map.take(Map.keys(headers2)) |> Enum.all?(fn {k, v} -> v == Map.get(headers, k) end)
+      end
+    end
+  end
+
+  describe "build/1 :params" do
+    test "returns nil if unspecified" do
+      opts = []
+
+      assert is_nil(Builder.build(:params, opts))
+    end
+
+    property "returns value from opts" do
+      check all params <- map_of(string_key(), string(:alphanumeric)) do
+        opts = [
+          params: params
+        ]
+
+        assert Builder.build(:params, opts) == params
+      end
+    end
+
+    property "filters params" do
+      # NOTE: this does NOT test nested filtering.
+      # That's tested with the Util function.
+
+      check all params1 <- map_of(string_key(), string(:alphanumeric)),
+                params2 <- map_of(string_key(), string(:alphanumeric)),
+                params = Map.merge(params1, params2) do
+        # filter keys in params1
+        stub(MockConfig, :get, fn :filter_parameters, _ -> Map.keys(params1) end)
+
+        opts = [
+          config: MockConfig,
+          params: params
+        ]
+
+        assert %{} = filtered_params = Builder.build(:params, opts)
+
+        assert filtered_params
+               |> Map.take(Map.keys(params1))
+               |> Map.values()
+               |> Enum.all?(&(&1 == "[FILTERED]"))
+
+        assert filtered_params |> Map.take(Map.keys(params2)) |> Enum.all?(fn {k, v} -> v == Map.get(params, k) end)
+      end
+    end
+  end
+
+  describe "build/1 :session" do
+    test "nil by default" do
+      opts = []
+
+      assert is_nil(Builder.build(:session, opts))
+    end
+
+    property "returns value from opts" do
+      check all session <- map_of(string_key(), string(:alphanumeric)) do
+        opts = [
+          session: session
+        ]
+
+        assert Builder.build(:session, opts) == session
+      end
+    end
+  end
+
+  defp string_key do
+    string(:alphanumeric, min_length: 3)
+  end
+
+  defp env do
+    member_of(["dev", "uat", "staging", "prod"])
+  end
+
+  defp hostname do
+    string(:alphanumeric, min_length: 3)
+  end
+end
diff --git a/test/airbrake/payload_test.exs b/test/airbrake/payload_test.exs
index 6fd94f4..9ddc56c 100644
--- a/test/airbrake/payload_test.exs
+++ b/test/airbrake/payload_test.exs
@@ -146,18 +146,19 @@ defmodule Airbrake.PayloadTest do
 
     test "sets params when given" do
       params = %{foo: 55, bar: "qux"}
-      assert %Payload{params: ^params} = Payload.new(@exception, @stacktrace, params: params)
+
+      assert %Payload{
+               params: %{"foo" => 55, "bar" => "qux"}
+             } = Payload.new(@exception, @stacktrace, params: params)
     end
 
     test "filters sensitive params" do
-      Application.put_env(:airbrake_client, :filter_parameters, ["password"])
-
+      # "password" is filtered out in `config/test.exs`
+      # Filtering is tested in more depth for `Airbrake.Payload.Builder`.
       params = %{"password" => "top_secret", "x" => "y"}
 
       assert %Payload{params: %{"password" => "[FILTERED]", "x" => "y"}} =
                Payload.new(@exception, @stacktrace, params: params)
-
-      Application.delete_env(:airbrake_client, :filter_parameters)
     end
 
     test "sets session when given" do

From 154c6c12c028b2e43f8c318d18d5d64003c8eee4 Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Thu, 28 Mar 2024 15:55:29 -0500
Subject: [PATCH 08/10] optionally add Logger metadata to session

---
 lib/airbrake/payload/builder.ex        | 16 ++++--
 lib/airbrake/worker.ex                 | 14 ++++-
 test/airbrake/payload/builder_test.exs | 73 +++++++++++++++++++++++---
 3 files changed, 93 insertions(+), 10 deletions(-)

diff --git a/lib/airbrake/payload/builder.ex b/lib/airbrake/payload/builder.ex
index 6e6053a..ffe16d0 100644
--- a/lib/airbrake/payload/builder.ex
+++ b/lib/airbrake/payload/builder.ex
@@ -41,9 +41,19 @@ defmodule Airbrake.Payload.Builder do
   end
 
   def build(:session, opts) do
-    if Keyword.has_key?(opts, :session),
-      do: opts |> Keyword.get(:session) |> Enum.into(%{}),
-      else: nil
+    config = get_config(opts)
+
+    logger_metadata =
+      if config.get(:session) == :include_logger_metadata,
+        do: Keyword.get(opts, :logger_metadata, []),
+        else: []
+
+    opts_session = opts |> Keyword.get(:session, %{}) |> Enum.into(%{})
+    full_session = logger_metadata |> Enum.into(%{}) |> Map.merge(opts_session)
+
+    if full_session == %{},
+      do: nil,
+      else: full_session
   end
 
   def filter_parameters(params, opts) do
diff --git a/lib/airbrake/worker.ex b/lib/airbrake/worker.ex
index 3c6b984..56d094b 100644
--- a/lib/airbrake/worker.ex
+++ b/lib/airbrake/worker.ex
@@ -28,7 +28,13 @@ defmodule Airbrake.Worker do
 
   def report([type: _, message: _] = exception, options) when is_list(options) do
     stacktrace = options[:stacktrace] || get_stacktrace()
-    GenServer.cast(@name, {:report, exception, stacktrace, Keyword.delete(options, :stacktrace)})
+
+    options =
+      options
+      |> Keyword.delete(:stacktrace)
+      |> maybe_add_logger_metadata()
+
+    GenServer.cast(@name, {:report, exception, stacktrace, options})
   end
 
   def report(_, _) do
@@ -136,6 +142,12 @@ defmodule Airbrake.Worker do
   defp ignore?(fun, type, message) when is_function(fun), do: fun.(type, message)
   defp ignore?(types, type, _message), do: MapSet.member?(types, type)
 
+  defp maybe_add_logger_metadata(opts) do
+    if Config.get(:session) == :include_logger_metadata,
+      do: Keyword.put(opts, :logger_metadata, Logger.metadata()),
+      else: opts
+  end
+
   defp process_name(pid, pid), do: "Process [#{inspect(pid)}]"
   defp process_name(pname, pid), do: "#{inspect(pname)} [#{inspect(pid)}]"
 
diff --git a/test/airbrake/payload/builder_test.exs b/test/airbrake/payload/builder_test.exs
index 56077c9..8fa094e 100644
--- a/test/airbrake/payload/builder_test.exs
+++ b/test/airbrake/payload/builder_test.exs
@@ -197,22 +197,83 @@ defmodule Airbrake.Payload.BuilderTest do
     end
   end
 
-  describe "build/1 :session" do
-    test "nil by default" do
-      opts = []
+  describe "build/1 :session and Logger metadata" do
+    test "nil if logger metadata is empty and :session not set" do
+      session_includes_metadata()
+
+      opts = [
+        config: MockConfig,
+        logger_metadata: []
+      ]
 
-      assert is_nil(Builder.build(:session, opts))
+      assert Builder.build(:session, opts) == nil
     end
 
-    property "returns value from opts" do
-      check all session <- map_of(string_key(), string(:alphanumeric)) do
+    test "nil if logger metadata is nil and :session not set" do
+      session_includes_metadata()
+
+      opts = [
+        config: MockConfig
+      ]
+
+      assert Builder.build(:session, opts) == nil
+    end
+
+    property "returns :session from opts over logger metadata" do
+      session_includes_metadata()
+
+      check all logger_metadata <- keyword_of(string(:alphanumeric)),
+                session <- map_of(string_key(), string(:alphanumeric)),
+                logger_metadata != [] or session != %{} do
         opts = [
+          config: MockConfig,
+          logger_metadata: logger_metadata,
+          session: session
+        ]
+
+        assert Builder.build(:session, opts) ==
+                 Map.merge(Map.new(logger_metadata), session)
+      end
+    end
+
+    defp session_includes_metadata do
+      stub(MockConfig, :get, fn :session -> :include_logger_metadata end)
+    end
+  end
+
+  describe "build/1 :session WITHOUT Logger metadata" do
+    property "nil if :session not set regardless of Logger metadata" do
+      session_does_not_includes_metadata()
+
+      check all logger_metadata <- keyword_of(string(:alphanumeric)) do
+        opts = [
+          config: MockConfig,
+          logger_metadata: logger_metadata
+        ]
+
+        assert Builder.build(:session, opts) == nil
+      end
+    end
+
+    property "returns :session from opts only" do
+      session_does_not_includes_metadata()
+
+      check all logger_metadata <- keyword_of(string(:alphanumeric)),
+                session <- map_of(string_key(), string(:alphanumeric)),
+                session != %{} do
+        opts = [
+          config: MockConfig,
+          logger_metadata: logger_metadata,
           session: session
         ]
 
         assert Builder.build(:session, opts) == session
       end
     end
+
+    defp session_does_not_includes_metadata do
+      stub(MockConfig, :get, fn :session -> nil end)
+    end
   end
 
   defp string_key do

From fdad7795147ccfd6297c6c47f68256b261307494 Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Thu, 28 Mar 2024 16:06:01 -0500
Subject: [PATCH 09/10] update README for new config option

---
 README.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/README.md b/README.md
index cbebf17..f3eb7b3 100644
--- a/README.md
+++ b/README.md
@@ -48,12 +48,16 @@ config :airbrake_client,
   environment: Mix.env(),
   filter_parameters: ["password"],
   filter_headers: ["authorization"],
+  session: :include_logger_metadata,
   host: "https://api.airbrake.io" # or your Errbit host
 
 config :logger,
   backends: [{Airbrake.LoggerBackend, :error}, :console]
 ```
 
+Split this config across your `config/*.exs` files (especially the runtime
+setting in `config/runtime.exs`).
+
 Required configuration arguments:
 
   * `:api_key` - (binary) the token needed to access the [Airbrake
@@ -74,6 +78,24 @@ Optional configuration arguments:
     to ignore some or all exceptions.  See examples below.
   * `:options` - (keyword list or function returning keyword list) values that
     are included in all reports to Airbrake.io.  See examples below.
+  * `:session` - can be set to `:include_logger_metadata` to include Logger
+    metadata in the `session` field of the report; omit this option if you do
+    not want Logger metadata.  See below for more information.
+
+### Logger metadata in the `session`
+
+If you set the `:session` config to `:include_logger_metadata`, the Logger
+metadata from the process that invokes `Airbrake.report/2` will be the initial
+session data for the `session` field.  The values passed as `:session` in the
+`options` parameter of `Airbrake.report/2` are _added_ to the session value,
+overwriting any Logger metadata values.
+
+If you do not set the `:session` config, only the `:session` value passed as the
+options to `Airbrake.report/2` will be used for the `session` field in the
+report.
+
+If the `session` turns out to be empty (for whatever reason), it is instead set
+to `nil` (and should not show up in the report).
 
 ### Ignoring some exceptions
 

From b64271ffa17460e1332abfe9a2334f5f4de05ee8 Mon Sep 17 00:00:00 2001
From: "Jeremy D. Frens" <jfrens@thecitybase.com>
Date: Thu, 28 Mar 2024 16:06:29 -0500
Subject: [PATCH 10/10] update CHANGELOG and bump to version 2.1.0

---
 CHANGELOG.md                                         | 10 +++++++++-
 .../jason_only_app/test/jason_only_app_test.exs      |  4 ++--
 .../poison_only_app/test/poison_only_app_test.exs    |  4 ++--
 mix.exs                                              |  2 +-
 test/airbrake/payload_test.exs                       | 12 ++++++------
 5 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d230ba5..362bdf3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog for v0.x
 
+## v2.1.0 (??????????)
+
+### Enhancements
+
+  * New config option: if `:session` is set to `:include_logger_metadata`, the
+    Logger metadata from `Logger.metadata/0` is added to the `session` field of
+    the report.  (If the option is not set, the metadata is not included.)
+
 ## v2.0.0 (2024-03-11)
 
 ### Enhancements
@@ -10,7 +18,7 @@
 ### Breaking Change
 
   * Drop support for Elixir <1.12
-    
+
 ## v1.0.0 (2023-10-12)
 
 ### Enhancements
diff --git a/integration_test_apps/jason_only_app/test/jason_only_app_test.exs b/integration_test_apps/jason_only_app/test/jason_only_app_test.exs
index 42e73d2..9067992 100644
--- a/integration_test_apps/jason_only_app/test/jason_only_app_test.exs
+++ b/integration_test_apps/jason_only_app/test/jason_only_app_test.exs
@@ -39,7 +39,7 @@ defmodule JasonOnlyAppTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => nil,
                "session" => nil
@@ -88,7 +88,7 @@ defmodule JasonOnlyAppTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => %{"foo" => 55},
                "session" => %{"foo" => 555}
diff --git a/integration_test_apps/poison_only_app/test/poison_only_app_test.exs b/integration_test_apps/poison_only_app/test/poison_only_app_test.exs
index 2865e89..c7a2ff2 100644
--- a/integration_test_apps/poison_only_app/test/poison_only_app_test.exs
+++ b/integration_test_apps/poison_only_app/test/poison_only_app_test.exs
@@ -40,7 +40,7 @@ defmodule PoisonOnlyAppTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => nil,
                "session" => nil
@@ -89,7 +89,7 @@ defmodule PoisonOnlyAppTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => %{"foo" => 55},
                "session" => %{"foo" => 555}
diff --git a/mix.exs b/mix.exs
index 31bd295..73330f6 100644
--- a/mix.exs
+++ b/mix.exs
@@ -4,7 +4,7 @@ defmodule Airbrake.Mixfile do
   def project do
     [
       app: :airbrake_client,
-      version: "2.0.0",
+      version: "2.1.0",
       elixir: "~> 1.12",
       elixirc_paths: elixirc_paths(Mix.env()),
       package: package(),
diff --git a/test/airbrake/payload_test.exs b/test/airbrake/payload_test.exs
index 9ddc56c..8956e43 100644
--- a/test/airbrake/payload_test.exs
+++ b/test/airbrake/payload_test.exs
@@ -48,7 +48,7 @@ defmodule Airbrake.PayloadTest do
                notifier: %{
                  name: "Airbrake Client",
                  url: "https://github.com/CityBaseInc/airbrake_client",
-                 version: "2.0.0"
+                 version: "2.1.0"
                }
              } = Payload.new(exception, stacktrace)
     end
@@ -105,7 +105,7 @@ defmodule Airbrake.PayloadTest do
                notifier: %{
                  name: "Airbrake Client",
                  url: "https://github.com/CityBaseInc/airbrake_client",
-                 version: "2.0.0"
+                 version: "2.1.0"
                }
              } = Payload.new(@exception, @stacktrace)
     end
@@ -198,7 +198,7 @@ defmodule Airbrake.PayloadTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => nil,
                "session" => nil
@@ -242,7 +242,7 @@ defmodule Airbrake.PayloadTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => %{"foo" => 55},
                "session" => %{"foo" => 555}
@@ -281,7 +281,7 @@ defmodule Airbrake.PayloadTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => nil,
                "session" => nil
@@ -325,7 +325,7 @@ defmodule Airbrake.PayloadTest do
                "notifier" => %{
                  "name" => "Airbrake Client",
                  "url" => "https://github.com/CityBaseInc/airbrake_client",
-                 "version" => "2.0.0"
+                 "version" => "2.1.0"
                },
                "params" => %{"foo" => 55},
                "session" => %{"foo" => 555}