Remove the private and internal extension system (#818)

This system was introduced eight years ago in this commit: dda717d It is currently unused. Let's remove it so we remove some unused code and can't confuse future readers. Fixes #817
appsignal · Feb 8, 2022 · 3f503ad · 3f503ad
1 parent 0e9b72f
commit 3f503ad
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Showing 4 changed files with 6 additions and 39 deletions.
diff --git a/.changesets/remove-internal-extensions-system.md b/.changesets/remove-internal-extensions-system.md
@@ -0,0 +1,6 @@
+---
+bump: "patch"
+type: "remove"
+---
+
+Remove internal `Appsignal.extensions` system. It was unused.
diff --git a/lib/appsignal.rb b/lib/appsignal.rb
@@ -58,20 +58,6 @@ class << self
     #   @see start_logger
     attr_writer :logger
 
-    # @api private
-    def extensions
-      @extensions ||= []
-    end
-
-    # @api private
-    def initialize_extensions
-      Appsignal.logger.debug("Initializing extensions")
-      extensions.each do |extension|
-        Appsignal.logger.debug("Initializing #{extension}")
-        extension.initializer
-      end
-    end
-
     # @api private
     def testing?
       false
@@ -123,7 +109,6 @@ def start
           config.write_to_environment
           Appsignal::Extension.start
           Appsignal::Hooks.load_hooks
-          initialize_extensions
 
           if config[:enable_allocation_tracking] && !Appsignal::System.jruby?
             Appsignal::Extension.install_allocation_event_hook

diff --git a/spec/lib/appsignal_spec.rb b/spec/lib/appsignal_spec.rb
@@ -5,7 +5,6 @@
     # Make sure we have a clean state because we want to test
     # initialization here.
     Appsignal.config = nil
-    Appsignal.extensions.clear
   end
 
   let(:transaction) { http_request_transaction }
@@ -20,14 +19,6 @@
     end
   end
 
-  describe ".extensions" do
-    it "should keep a list of extensions" do
-      expect(Appsignal.extensions).to be_empty
-      Appsignal.extensions << Appsignal::MockExtension
-      expect(Appsignal.extensions.size).to eq(1)
-    end
-  end
-
   describe ".start" do
     context "with no config set beforehand" do
       it "should do nothing when config is not set and there is no valid config in the env" do
@@ -63,15 +54,6 @@
         Appsignal.start
       end
 
-      context "with an extension" do
-        before { Appsignal.extensions << Appsignal::MockExtension }
-
-        it "should call the extension's initializer" do
-          expect(Appsignal::MockExtension).to receive(:initializer)
-          Appsignal.start
-        end
-      end
-
       context "when allocation tracking and gc instrumentation have been enabled" do
         before do
           allow(GC::Profiler).to receive(:enable)

diff --git a/spec/support/mocks/mock_extension.rb b/spec/support/mocks/mock_extension.rb