Add max_nesting of 5 to breadcrumbs data serialization

This is [enforced in [relay](https://github.com/getsentry/relay/blob/bcbfa7e7db6e4a8f3f0383270fbb2b5cfe668770/relay-event-schema/src/protocol/breadcrumb.rs#L111)
either way so this is not a behavioral change.

Closes #2393 and #2397

Author: sl0thentr0py

CHANGELOG.md

@@ -1,3 +1,9 @@
+## Unreleased
+
+- Add `max_nesting` of 5 to breadcrumbs data serialization ([#2549](https://github.com/getsentry/sentry-ruby/pull/2549))
+
+### Features
+
 ## 5.23.0
 
 ### Features

sentry-ruby/lib/sentry/breadcrumb.rb

@@ -2,6 +2,7 @@
 
 module Sentry
   class Breadcrumb
+    MAX_NESTING = 5
     DATA_SERIALIZATION_ERROR_MESSAGE = "[data were removed due to serialization issues]"
 
     # @return [String, nil]
@@ -60,7 +61,7 @@ def level=(level) # needed to meet the Sentry spec
 
     def serialized_data
       begin
-        ::JSON.parse(::JSON.generate(@data))
+        ::JSON.parse(::JSON.generate(@data, max_nesting: MAX_NESTING))
       rescue Exception => e
         Sentry.logger.debug(LOGGER_PROGNAME) do
           <<~MSG

sentry-ruby/spec/sentry/breadcrumb_spec.rb

@@ -3,8 +3,12 @@
 require "spec_helper"
 
 RSpec.describe Sentry::Breadcrumb do
+  let(:stringio) { StringIO.new }
+
   before do
-    perform_basic_setup
+    perform_basic_setup do |config|
+      config.logger = ::Logger.new(stringio)
+    end
   end
 
   let(:crumb) do
@@ -71,6 +75,16 @@
       )
     end
 
+    let(:very_deep_crumb) do
+      data = [[ { a: [{ b: [{ c: 4 }] }] }]]
+
+      Sentry::Breadcrumb.new(
+        category: "cow",
+        message: "I cause too much recursion",
+        data: data
+      )
+    end
+
     it "serializes data correctly" do
       result = crumb.to_hash
 
@@ -85,6 +99,16 @@
       expect(result[:category]).to eq("baz")
       expect(result[:message]).to eq("I cause issues")
       expect(result[:data]).to eq("[data were removed due to serialization issues]")
+      expect(stringio.string).to match(/can't serialize breadcrumb data because of error: nesting of 5 is too deep/)
+    end
+
+    it "rescues data serialization issue for extremely nested data and ditch the data" do
+      result = very_deep_crumb.to_hash
+
+      expect(result[:category]).to eq("cow")
+      expect(result[:message]).to eq("I cause too much recursion")
+      expect(result[:data]).to eq("[data were removed due to serialization issues]")
+      expect(stringio.string).to match(/can't serialize breadcrumb data because of error: nesting of 5 is too deep/)
     end
   end
 end