Slightly reduce RAM usage (#7301)

* No need to re-require sidekiq plugins, they are required via Gemfile

* Add derailed_benchmarks tool, no need to require TTY gems in Gemfile

* Replace ruby-oembed with FetchOEmbedService

Reduce startup by 45382 allocated objects

* Remove preloaded JSON-LD in favour of caching HTTP responses

Reduce boot RAM by about 6 MiB

* Fix tests

* Fix test suite by stubbing out JSON-LD contexts

2 files changed, 4 insertions, 118 deletions

diff --git a/spec/lib/activitypub/linked_data_signature_spec.rb b/spec/lib/activitypub/linked_data_signature_spec.rb
index a4d6fe8c3..1f413eec9 100644
--- a/spec/lib/activitypub/linked_data_signature_spec.rb
+++ b/spec/lib/activitypub/linked_data_signature_spec.rb
@@ -16,6 +16,10 @@ RSpec.describe ActivityPub::LinkedDataSignature do
 
   subject { described_class.new(json) }
 
+  before do
+    stub_jsonld_contexts!
+  end
+
   describe '#verify_account!' do
     context 'when signature matches' do
       let(:raw_signature) do
diff --git a/spec/lib/provider_discovery_spec.rb b/spec/lib/provider_discovery_spec.rb
deleted file mode 100644
index de2ac16f9..000000000
--- a/spec/lib/provider_discovery_spec.rb
+++ /dev/null
@@ -1,118 +0,0 @@
-# frozen_string_literal: true
-
-require 'rails_helper'
-
-describe ProviderDiscovery do
-  describe 'discover_provider' do
-    context 'when status code is 200 and MIME type is text/html' do
-      context 'Both of JSON and XML provider are discoverable' do
-        before do
-          stub_request(:get, 'https://host.test/oembed.html').to_return(
-            status: 200,
-            headers: { 'Content-Type': 'text/html' },
-            body: request_fixture('oembed_json_xml.html')
-          )
-        end
-
-        it 'returns new OEmbed::Provider for JSON provider if :format option is set to :json' do
-          provider = ProviderDiscovery.discover_provider('https://host.test/oembed.html', format: :json)
-          expect(provider.endpoint).to eq 'https://host.test/provider.json'
-          expect(provider.format).to eq :json
-        end
-
-        it 'returns new OEmbed::Provider for XML provider if :format option is set to :xml' do
-          provider = ProviderDiscovery.discover_provider('https://host.test/oembed.html', format: :xml)
-          expect(provider.endpoint).to eq 'https://host.test/provider.xml'
-          expect(provider.format).to eq :xml
-        end
-      end
-
-      context 'JSON provider is discoverable while XML provider is not' do
-        before do
-          stub_request(:get, 'https://host.test/oembed.html').to_return(
-            status: 200,
-            headers: { 'Content-Type': 'text/html' },
-            body: request_fixture('oembed_json.html')
-          )
-        end
-
-        it 'returns new OEmbed::Provider for JSON provider' do
-          provider = ProviderDiscovery.discover_provider('https://host.test/oembed.html')
-          expect(provider.endpoint).to eq 'https://host.test/provider.json'
-          expect(provider.format).to eq :json
-        end
-      end
-
-      context 'XML provider is discoverable while JSON provider is not' do
-        before do
-          stub_request(:get, 'https://host.test/oembed.html').to_return(
-            status: 200,
-            headers: { 'Content-Type': 'text/html' },
-            body: request_fixture('oembed_xml.html')
-          )
-        end
-
-        it 'returns new OEmbed::Provider for XML provider' do
-          provider = ProviderDiscovery.discover_provider('https://host.test/oembed.html')
-          expect(provider.endpoint).to eq 'https://host.test/provider.xml'
-          expect(provider.format).to eq :xml
-        end
-      end
-
-      context 'Invalid XML provider is discoverable while JSON provider is not' do
-        before do
-          stub_request(:get, 'https://host.test/oembed.html').to_return(
-            status: 200,
-            headers: { 'Content-Type': 'text/html' },
-            body: request_fixture('oembed_invalid_xml.html')
-          )
-        end
-
-        it 'raises OEmbed::NotFound' do
-          expect { ProviderDiscovery.discover_provider('https://host.test/oembed.html') }.to raise_error OEmbed::NotFound
-        end
-      end
-
-      context 'Neither of JSON and XML provider is discoverable' do
-        before do
-          stub_request(:get, 'https://host.test/oembed.html').to_return(
-            status: 200,
-            headers: { 'Content-Type': 'text/html' },
-            body: request_fixture('oembed_undiscoverable.html')
-          )
-        end
-
-        it 'raises OEmbed::NotFound' do
-          expect { ProviderDiscovery.discover_provider('https://host.test/oembed.html') }.to raise_error OEmbed::NotFound
-        end
-      end
-    end
-
-    context 'when status code is not 200' do
-      before do
-        stub_request(:get, 'https://host.test/oembed.html').to_return(
-          status: 400,
-          headers: { 'Content-Type': 'text/html' },
-          body: request_fixture('oembed_xml.html')
-        )
-      end
-
-      it 'raises OEmbed::NotFound' do
-        expect { ProviderDiscovery.discover_provider('https://host.test/oembed.html') }.to raise_error OEmbed::NotFound
-      end
-    end
-
-    context 'when MIME type is not text/html' do
-      before do
-        stub_request(:get, 'https://host.test/oembed.html').to_return(
-          status: 200,
-          body: request_fixture('oembed_xml.html')
-        )
-      end
-
-      it 'raises OEmbed::NotFound' do
-        expect { ProviderDiscovery.discover_provider('https://host.test/oembed.html') }.to raise_error OEmbed::NotFound
-      end
-    end
-  end
-end