From ef87d0b35f51a1de64dbbeb3c58da4c2fa33875d Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Wed, 7 Dec 2016 16:46:00 -0600
Subject: [PATCH 1/8] add filter behavior

---
 lib/sentry/event_filter.ex | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 lib/sentry/event_filter.ex

diff --git a/lib/sentry/event_filter.ex b/lib/sentry/event_filter.ex
new file mode 100644
index 00000000..5fd21d59
--- /dev/null
+++ b/lib/sentry/event_filter.ex
@@ -0,0 +1,8 @@
+defmodule Sentry.EventFilter do
+  @callback exclude_exception?(atom, Exception.t) :: any
+end
+
+defmodule Sentry.DefaultEventFilter do
+  @behaviour Sentry.EventFilter
+  def exclude_exception?(_, _), do: false
+end

From 11f0364820cddefa179ec3fb06a84cb90c317124 Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Wed, 7 Dec 2016 16:46:50 -0600
Subject: [PATCH 2/8] filtering functionality

---
 lib/sentry.ex        | 9 ++++++---
 lib/sentry/logger.ex | 6 ++++--
 lib/sentry/plug.ex   | 2 +-
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/sentry.ex b/lib/sentry.ex
index 916302b6..dd6f9fd5 100644
--- a/lib/sentry.ex
+++ b/lib/sentry.ex
@@ -84,9 +84,12 @@ defmodule Sentry do
   """
   @spec capture_exception(Exception.t, Keyword.t) :: {:ok, String.t} | :error
   def capture_exception(exception, opts \\ []) do
-    exception
-    |> Event.transform_exception(opts)
-    |> send_event()
+    filter_module = Application.get_env(:sentry, :filter, Sentry.DefaultEventFilter)
+    {source, opts} = Keyword.pop(opts, :event_source)
+    unless(filter_module.exclude_exception?(exception, source)) do
+      Event.transform_exception(exception, opts)
+      |> send_event()
+    end
   end
 
   @doc """
diff --git a/lib/sentry/logger.ex b/lib/sentry/logger.ex
index 05031739..20937aa6 100644
--- a/lib/sentry/logger.ex
+++ b/lib/sentry/logger.ex
@@ -34,10 +34,12 @@ defmodule Sentry.Logger do
       case error_info do
         {_kind, {exception, stacktrace}, _stack} when is_list(stacktrace) ->
           opts = Keyword.put(opts, :stacktrace, stacktrace)
-          Sentry.capture_exception(exception, opts) 
+          |> Keyword.put(:event_source, :logger)
+          Sentry.capture_exception(exception, opts)
         {_kind, exception, stacktrace} ->
           opts = Keyword.put(opts, :stacktrace, stacktrace)
-          Sentry.capture_exception(exception, opts) 
+          |> Keyword.put(:event_source, :logger)
+          Sentry.capture_exception(exception, opts)
       end
     rescue
       ex ->
diff --git a/lib/sentry/plug.ex b/lib/sentry/plug.ex
index 2fd51140..06e091fe 100644
--- a/lib/sentry/plug.ex
+++ b/lib/sentry/plug.ex
@@ -87,7 +87,7 @@ defmodule Sentry.Plug do
                  request_id_header: unquote(request_id_header)]
         request = Sentry.Plug.build_request_interface_data(conn, opts)
         exception = Exception.normalize(kind, reason, stack)
-        Sentry.capture_exception(exception, [stacktrace: stack, request: request])
+        Sentry.capture_exception(exception, [stacktrace: stack, request: request, event_source: :plug])
       end
     end
   end

From 7dc1d1585b1d31a3cf25e23c84f9675053f88c68 Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Wed, 7 Dec 2016 16:47:02 -0600
Subject: [PATCH 3/8] test

---
 test/sentry_test.exs        | 23 ++++++++++++++++++++++-
 test/support/test_filter.ex |  6 ++++++
 2 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 test/support/test_filter.ex

diff --git a/test/sentry_test.exs b/test/sentry_test.exs
index ec6b8cc3..ecae8fa5 100644
--- a/test/sentry_test.exs
+++ b/test/sentry_test.exs
@@ -1,3 +1,24 @@
 defmodule SentryTest do
-  use ExUnit.Case, async: true
+  use ExUnit.Case
+
+  test "excludes events properly" do
+   Application.put_env(:sentry, :filter, Sentry.TestFilter)
+
+
+   bypass = Bypass.open
+   Bypass.expect bypass, fn conn ->
+     {:ok, body, conn} = Plug.Conn.read_body(conn)
+     assert body =~ "RuntimeError"
+     assert conn.request_path == "/api/1/store/"
+     assert conn.method == "POST"
+     Plug.Conn.resp(conn, 200, ~s<{"id": "340"}>)
+   end
+
+   Application.put_env(:sentry, :dsn, "http://public:secret@localhost:#{bypass.port}/1")
+   Application.put_env(:sentry, :included_environments, [:test])
+   Application.put_env(:sentry, :environment_name, :test)
+
+   Sentry.capture_exception(%RuntimeError{message: "error"}, [event_source: :plug])
+   Sentry.capture_exception(%ArithmeticError{message: "error"}, [event_source: :plug])
+  end
 end
diff --git a/test/support/test_filter.ex b/test/support/test_filter.ex
new file mode 100644
index 00000000..7fcdafb1
--- /dev/null
+++ b/test/support/test_filter.ex
@@ -0,0 +1,6 @@
+defmodule Sentry.TestFilter do
+  @behaviour Sentry.Filter
+
+  def exclude_exception?(%ArithmeticError{}, :plug), do: true
+  def exclude_exception?(_, _), do: false
+end

From 2c01fe84a51ff383a6b64439e9d6bd47d0e62928 Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Thu, 8 Dec 2016 15:41:40 -0600
Subject: [PATCH 4/8] update changelog

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c0d97ffd..8d64fd3e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## master
 
+* Enhancements
+  * Allow filtering which exceptions are sent via `Sentry.Filter` behaviour
+
 * Bug Fixes
   * Fix usage of deprecated modules
 

From baada7e29ada3638a29a90180f7032b4582f75ab Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Thu, 8 Dec 2016 16:05:01 -0600
Subject: [PATCH 5/8] add hex docs

---
 lib/sentry.ex | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/lib/sentry.ex b/lib/sentry.ex
index dd6f9fd5..f2b6e34a 100644
--- a/lib/sentry.ex
+++ b/lib/sentry.ex
@@ -51,11 +51,40 @@ defmodule Sentry do
   our local development machines, exceptions will never be sent, because the
   default value is not in the list of `included_environments`.
 
+  ## Filtering Exceptions
+
+  If you would like to prevent certain exceptions, the :filter configuration option
+  allows you to implement the `Sentry.Filter` behaviour.  The first argument is the
+  source of the event, and the second is the exception to be sent.  `Sentry.Plug`
+  will have a source of `:plug`, and `Sentry.Logger` will have a source of `:logger`.
+  If an exception does not come from either of those sources, the source will be nil
+  unless the `:event_source` option is passed to `Sentry.capture_exception/2`
+
+  A configuration like below will prevent sending `Phoenix.Router.NoRouteError` from `Sentry.Plug`, but
+  allows other exceptions to be sent.
+
+      # sentry_event_filter.exs
+      defmodule MyApp.SentryEventFilter do
+        @behaviour Sentry.Filter
+
+        def exclude_exception?(:plug, %Elixir.Phoenix.Router.NoRouteError{}), do: true
+        def exclude_exception?(_, ), do: false
+      end
+
+      # config.exs
+      config :sentry, filter: MyApp.SentryEventFilter,
+        included_environments: ~w(production staging),
+        environment_name: System.get_env("RELEASE_LEVEL") || "development"
+
   ## Capturing Exceptions
 
-  Simply calling `capture_exception\2` will send the event.
+  Simply calling `capture_exception/2` will send the event.
 
       Sentry.capture_exception(my_exception)
+      Sentry.capture_exception(other_exception, [source_name: :my_source])
+
+  ### Options
+    * `:event_source` - The source passed as the first argument to `Sentry.Filter.exclude_exception?/2`
 
   ## Configuring The `Logger` Backend
 

From edd78f8e242472743989cd0f3bf31aba7e287708 Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Thu, 8 Dec 2016 16:10:54 -0600
Subject: [PATCH 6/8] use correct behaviour name

---
 CHANGELOG.md                | 2 +-
 lib/sentry.ex               | 6 +++---
 test/support/test_filter.ex | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d64fd3e..07286ffe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,7 +3,7 @@
 ## master
 
 * Enhancements
-  * Allow filtering which exceptions are sent via `Sentry.Filter` behaviour
+  * Allow filtering which exceptions are sent via `Sentry.EventFilter` behaviour
 
 * Bug Fixes
   * Fix usage of deprecated modules
diff --git a/lib/sentry.ex b/lib/sentry.ex
index f2b6e34a..fa173df0 100644
--- a/lib/sentry.ex
+++ b/lib/sentry.ex
@@ -54,7 +54,7 @@ defmodule Sentry do
   ## Filtering Exceptions
 
   If you would like to prevent certain exceptions, the :filter configuration option
-  allows you to implement the `Sentry.Filter` behaviour.  The first argument is the
+  allows you to implement the `Sentry.EventFilter` behaviour.  The first argument is the
   source of the event, and the second is the exception to be sent.  `Sentry.Plug`
   will have a source of `:plug`, and `Sentry.Logger` will have a source of `:logger`.
   If an exception does not come from either of those sources, the source will be nil
@@ -65,7 +65,7 @@ defmodule Sentry do
 
       # sentry_event_filter.exs
       defmodule MyApp.SentryEventFilter do
-        @behaviour Sentry.Filter
+        @behaviour Sentry.EventFilter
 
         def exclude_exception?(:plug, %Elixir.Phoenix.Router.NoRouteError{}), do: true
         def exclude_exception?(_, ), do: false
@@ -84,7 +84,7 @@ defmodule Sentry do
       Sentry.capture_exception(other_exception, [source_name: :my_source])
 
   ### Options
-    * `:event_source` - The source passed as the first argument to `Sentry.Filter.exclude_exception?/2`
+    * `:event_source` - The source passed as the first argument to `Sentry.EventFilter.exclude_exception?/2`
 
   ## Configuring The `Logger` Backend
 
diff --git a/test/support/test_filter.ex b/test/support/test_filter.ex
index 7fcdafb1..dcd76ac1 100644
--- a/test/support/test_filter.ex
+++ b/test/support/test_filter.ex
@@ -1,5 +1,5 @@
 defmodule Sentry.TestFilter do
-  @behaviour Sentry.Filter
+  @behaviour Sentry.EventFilter
 
   def exclude_exception?(%ArithmeticError{}, :plug), do: true
   def exclude_exception?(_, _), do: false

From 9b8ec9c2d99b90f9de8c4902b392067c23fac2f8 Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Thu, 8 Dec 2016 16:12:39 -0600
Subject: [PATCH 7/8] return :excluded instead of nil

---
 lib/sentry.ex        | 6 ++++--
 test/sentry_test.exs | 4 ++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/lib/sentry.ex b/lib/sentry.ex
index fa173df0..43b70101 100644
--- a/lib/sentry.ex
+++ b/lib/sentry.ex
@@ -111,11 +111,13 @@ defmodule Sentry do
   @doc """
     Parses and submits an exception to Sentry if current environment is in included_environments.
   """
-  @spec capture_exception(Exception.t, Keyword.t) :: {:ok, String.t} | :error
+  @spec capture_exception(Exception.t, Keyword.t) :: {:ok, String.t} | :error | :excluded
   def capture_exception(exception, opts \\ []) do
     filter_module = Application.get_env(:sentry, :filter, Sentry.DefaultEventFilter)
     {source, opts} = Keyword.pop(opts, :event_source)
-    unless(filter_module.exclude_exception?(exception, source)) do
+    if(filter_module.exclude_exception?(exception, source)) do
+      :excluded
+    else
       Event.transform_exception(exception, opts)
       |> send_event()
     end
diff --git a/test/sentry_test.exs b/test/sentry_test.exs
index ecae8fa5..4bbb50fb 100644
--- a/test/sentry_test.exs
+++ b/test/sentry_test.exs
@@ -18,7 +18,7 @@ defmodule SentryTest do
    Application.put_env(:sentry, :included_environments, [:test])
    Application.put_env(:sentry, :environment_name, :test)
 
-   Sentry.capture_exception(%RuntimeError{message: "error"}, [event_source: :plug])
-   Sentry.capture_exception(%ArithmeticError{message: "error"}, [event_source: :plug])
+   assert {:ok, _} = Sentry.capture_exception(%RuntimeError{message: "error"}, [event_source: :plug])
+   assert :excluded = Sentry.capture_exception(%ArithmeticError{message: "error"}, [event_source: :plug])
   end
 end

From e695f448304f07000cdd9a08f5d9724994dab1cc Mon Sep 17 00:00:00 2001
From: Mitchell Henke <mitchh23@gmail.com>
Date: Thu, 8 Dec 2016 16:37:17 -0600
Subject: [PATCH 8/8] sentry docs

---
 docs/config.rst |  5 +++++
 docs/index.rst  | 27 +++++++++++++++++++++++++++
 docs/usage.rst  |  3 +++
 3 files changed, 35 insertions(+)

diff --git a/docs/config.rst b/docs/config.rst
index f39b5d7d..cdb558ad 100644
--- a/docs/config.rst
+++ b/docs/config.rst
@@ -52,6 +52,11 @@ Optional settings
   Set this to true if you want to capture all exceptions that occur even outside of a request cycle. This
   defaults to false.
 
+.. describe:: filter
+
+  Set this to a module that implements the ``Sentry.EventFilter`` behaviour if you would like to prevent
+  certain exceptions from being sent.  See below for further documentation.
+
 Testing Your Configuration
 --------------------------
 
diff --git a/docs/index.rst b/docs/index.rst
index 0fc8cd1e..85618191 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -107,6 +107,33 @@ new process and it fails you might lose your context. That said using the contex
   # adds an breadcrumb to the request to help debug
   Sentry.Context.add_breadcrumb(%{my: "crumb"})
 
+Filtering Events
+--------------
+
+If you would like to prevent certain exceptions, the :filter configuration option
+allows you to implement the ``Sentry.EventFilter`` behaviour.  The first argument is the
+source of the event, and the second is the exception to be sent.  ``Sentry.Plug``
+will have a source of ``:plug``, and ``Sentry.Logger`` will have a source of ``:logger``.
+If an exception does not come from either of those sources, the source will be nil
+unless the ``:event_source`` option is passed to ``Sentry.capture_exception/2``
+
+A configuration like below will prevent sending ``Phoenix.Router.NoRouteError`` from ``Sentry.Plug``, but
+allows other exceptions to be sent.
+
+.. code-block:: elixir
+  # sentry_event_filter.exs
+  defmodule MyApp.SentryEventFilter do
+    @behaviour Sentry.EventFilter
+
+    def exclude_exception?(:plug, %Elixir.Phoenix.Router.NoRouteError{}), do: true
+    def exclude_exception?(_, ), do: false
+  end
+
+  # config.exs
+  config :sentry, filter: MyApp.SentryEventFilter,
+    included_environments: ~w(production staging),
+    environment_name: System.get_env("RELEASE_LEVEL") || "development"
+
 Deep Dive
 ---------
 
diff --git a/docs/usage.rst b/docs/usage.rst
index 86d88559..c546be88 100644
--- a/docs/usage.rst
+++ b/docs/usage.rst
@@ -71,6 +71,9 @@ With calls to ``capture_exception`` additional data can be supplied as a keyword
             "email" => "clever-girl"
         }
 
+.. describe:: event_source
+
+    The source of the event.  Used by the `Sentry.EventFilter` behaviour.
 
 Breadcrumbs
 -----------