Add some tests

lib/datadog/core/crashtracking/component.rb

@@ -33,10 +33,10 @@ def self.build(settings, agent_settings, logger:)
           agent_base_url = AgentBaseUrl.resolve(agent_settings)
           logger.warn('Missing agent base URL; cannot enable crash tracking') unless agent_base_url
 
-          ld_library_path = Libdatadog.ld_library_path
+          ld_library_path = ::Libdatadog.ld_library_path
           logger.warn('Missing ld_library_path; cannot enable crash tracking') unless ld_library_path
 
-          path_to_crashtracking_receiver_binary = Libdatadog.path_to_crashtracking_receiver_binary
+          path_to_crashtracking_receiver_binary = ::Libdatadog.path_to_crashtracking_receiver_binary
           unless path_to_crashtracking_receiver_binary
             logger.warn('Missing path_to_crashtracking_receiver_binary; cannot enable crash tracking')
           end
@@ -61,20 +61,16 @@ def initialize(tags:, agent_base_url:, ld_library_path:, path_to_crashtracking_r
         end
 
         def start
-          Datadog::Core::Utils::AtForkMonkeyPatch.apply!
+          Utils::AtForkMonkeyPatch.apply!
 
           start_or_update_on_fork(action: :start)
           reset_after_fork
         end
 
         def reset_after_fork
           ONLY_ONCE.run do
-            if Process.respond_to?(:datadog_at_fork)
-              Process.datadog_at_fork(:child) do
-                start_or_update_on_fork(action: :update_on_fork)
-              end
-            else
-              logger.debug 'Unexpected: At fork hooks not available'
+            Utils::AtForkMonkeyPatch.at_fork(:child) do
+              start_or_update_on_fork(action: :update_on_fork)
             end
           end
         end

sig/datadog/core/utils/at_fork_monkey_patch.rbs

@@ -1 +1,27 @@
-# TODO
+module Datadog
+  module Core
+    module Utils
+      module AtForkMonkeyPatch
+        AT_FORK_CHILD_BLOCKS: ::Array[untyped]
+
+        def self.supported?: () -> untyped
+
+        def self.apply!: () -> (false | true)
+
+        def self.run_at_fork_blocks: (untyped stage) -> untyped
+
+        def self.at_fork: (untyped stage) ?{ () -> untyped } -> true
+
+        module KernelMonkeyPatch
+          def fork: () ?{ () -> untyped } -> untyped
+        end
+
+        module ProcessMonkeyPatch
+          def _fork: () -> untyped
+
+          def daemon: (*untyped args) -> untyped
+        end
+      end
+    end
+  end
+end