Store Ash bread crumbs in occurrence context (#106)

Some frameworks such as Ash include breadcrumbs in their errors. This is
provided by the fantastic Splode library
([details](https://bsky.app/profile/zachdaniel.dev/post/3l7qsyil4pg2c)).

This commit updates the ErrorTracker to detect such bread crumbs and
include them in the occurrence context. In the future we may want to
revisit this and store them in their own field separate from the
context.

It is important to note that you don't have to use Ash or Splode to
leverage this integration. Breadcrumbs will be automatically extracted
from any exception that includes a `bread_crumbs` field.

I've discussed this with @zachdaniel and he kindly integrated the
breadcrumbs on Ash main for create and change actions.

Author: crbelaus

lib/error_tracker.ex

@@ -120,6 +120,11 @@ defmodule ErrorTracker do
     {:ok, error} = Error.new(kind, reason, stacktrace)
     context = Map.merge(get_context(), given_context)
 
+    context =
+      if bread_crumbs = bread_crumbs(exception),
+        do: Map.put(context, "bread_crumbs", bread_crumbs),
+        else: context
+
     if enabled?() && !ignored?(error, context) do
       sanitized_context = sanitize_context(context)
       {_error, occurrence} = upsert_error!(error, stacktrace, sanitized_context, reason)
@@ -232,6 +237,14 @@ defmodule ErrorTracker do
     end
   end
 
+  defp bread_crumbs(exception) do
+    case exception do
+      {_kind, exception} -> bread_crumbs(exception)
+      %{bread_crumbs: bread_crumbs} -> bread_crumbs
+      _other -> nil
+    end
+  end
+
   defp upsert_error!(error, stacktrace, context, reason) do
     existing_status =
       Repo.one(from e in Error, where: [fingerprint: ^error.fingerprint], select: e.status)

test/error_tracker_test.exs

@@ -99,6 +99,17 @@ defmodule ErrorTrackerTest do
     test "with enabled flag to false it does not store the exception" do
       assert report_error(fn -> raise "Sample error" end) == :noop
     end
+
+    test "includes bread crumbs in the context if present" do
+      bread_crumbs = ["bread crumb 1", "bread crumb 2"]
+
+      occurrence =
+        report_error(fn ->
+          raise ErrorWithBreadcrumbs, message: "test", bread_crumbs: bread_crumbs
+        end)
+
+      assert occurrence.context["bread_crumbs"] == bread_crumbs
+    end
   end
 
   describe inspect(&ErrorTracker.resolve/1) do
@@ -119,3 +130,7 @@ defmodule ErrorTrackerTest do
     end
   end
 end
+
+defmodule ErrorWithBreadcrumbs do
+  defexception [:message, :bread_crumbs]
+end