FEATURE: Add scheduled Twitter login problem check - Part 1 (#25830)

This PR adds a new scheduled problem check that simply tries to connect to Twitter OAuth endpoint to check that it's working. It is using the default retry strategy of 2 retries 30 seconds apart.

config/locales/server.en.yml

@@ -1506,6 +1506,7 @@ en:
       description: "Top 10 users who have had likes from a wide range of people."
 
   dashboard:
+    twitter_login_warning: 'Twitter login appears to not be working at the moment. Check the credentials in <a href="%{base_path}/admin/site_settings/category/login?filter=twitter">the Site Settings</a>.'
     group_email_credentials_warning: 'There was an issue with the email credentials for the group <a href="%{base_path}/g/%{group_name}/manage/email">%{group_full_name}</a>. No emails will be sent from the group inbox until this problem is addressed. %{error}'
     rails_env_warning: "Your server is running in %{env} mode."
     host_names_warning: "Your config/database.yml file is using the default localhost hostname. Update it to use your site's hostname."

lib/auth/twitter_authenticator.rb

@@ -9,6 +9,16 @@ class Auth::TwitterAuthenticator < Auth::ManagedAuthenticator
     SiteSetting.enable_twitter_logins
   end
 
+  def healthy?
+    connection =
+      Faraday.new(url: "https://api.twitter.com") do |config|
+        config.basic_auth(SiteSetting.twitter_consumer_key, SiteSetting.twitter_consumer_secret)
+      end
+    connection.post("/oauth2/token").status == 200
+  rescue Faraday::Error
+    false
+  end
+
   def after_authenticate(auth_token, existing_account: nil)
     # Twitter sends a huge amount of data which we don't need, so ignore it
     auth_token[:extra] = {}

lib/problem_check.rb

@@ -3,6 +3,8 @@
 class ProblemCheck
   include ActiveSupport::Configurable
 
+  config_accessor :priority, default: "low", instance_writer: false
+
   # Determines if the check should be performed at a regular interval, and if
   # so how often. If left blank, the check will be performed every time the
   # admin dashboard is loaded, or the data is otherwise requested.
@@ -50,4 +52,25 @@ class ProblemCheck
   def call
     raise NotImplementedError
   end
+
+  private
+
+  def problem
+    [
+      Problem.new(
+        I18n.t(translation_key, base_path: Discourse.base_path),
+        priority: self.config.priority,
+        identifier:,
+      ),
+    ]
+  end
+
+  def no_problem
+    []
+  end
+
+  def translation_key
+    # TODO: Infer a default based on class name, then move translations in locale file.
+    raise NotImplementedError
+  end
 end

lib/problem_check/twitter_login.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class ProblemCheck::TwitterLogin < ProblemCheck
+  self.priority = "high"
+
+  # TODO: Implement.
+  self.perform_every = 24.hours
+
+  def call
+    return no_problem if !authenticator.enabled?
+    return no_problem if authenticator.healthy?
+
+    problem
+  end
+
+  private
+
+  def authenticator
+    @authenticator ||= Auth::TwitterAuthenticator.new
+  end
+
+  def translation_key
+    "dashboard.twitter_login_warning"
+  end
+end

spec/jobs/problem_checks_spec.rb

@@ -34,4 +34,13 @@ RSpec.describe Jobs::ProblemChecks do
       },
     ) { described_class.new.execute([]) }
   end
+
+  it "does not schedule non-scheduled checks" do
+    expect_not_enqueued_with(
+      job: :problem_check,
+      args: {
+        check_identifier: "non_scheduled_check",
+      },
+    ) { described_class.new.execute([]) }
+  end
 end

spec/lib/auth/twitter_authenticator_spec.rb

@@ -65,4 +65,37 @@ RSpec.describe Auth::TwitterAuthenticator do
       expect(authenticator.description_for_user(user)).to eq("")
     end
   end
+
+  describe "#healthy?" do
+    let(:authenticator) { described_class.new }
+
+    let(:connection) { mock("Faraday::Connection") }
+    let(:response) { mock("Faraday::Response") }
+
+    before do
+      Faraday.stubs(:new).returns(connection)
+      connection.stubs(:post).returns(response)
+      response.stubs(:status).returns(status)
+    end
+
+    context "when endpoint is reachable" do
+      let(:status) { 200 }
+
+      it { expect(authenticator).to be_healthy }
+    end
+
+    context "when credentials aren't recognized" do
+      let(:status) { 403 }
+
+      it { expect(authenticator).not_to be_healthy }
+    end
+
+    context "when an unexpected error happens" do
+      let(:status) { anything }
+
+      before { connection.stubs(:post).raises(Faraday::ServerError) }
+
+      it { expect(authenticator).not_to be_healthy }
+    end
+  end
 end

spec/lib/problem_check/twitter_login_spec.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+RSpec.describe ProblemCheck::TwitterLogin do
+  let(:problem_check) { described_class.new }
+
+  let(:authenticator) { mock("Auth::TwitterAuthenticator") }
+
+  before { Auth::TwitterAuthenticator.stubs(:new).returns(authenticator) }
+
+  describe "#call" do
+    context "when Twitter authentication isn't enabled" do
+      before { authenticator.stubs(:enabled?).returns(false) }
+
+      it { expect(problem_check.call).to be_empty }
+    end
+
+    context "when Twitter authentication appears to work" do
+      before do
+        authenticator.stubs(:enabled?).returns(true)
+        authenticator.stubs(:healthy?).returns(true)
+      end
+
+      it { expect(problem_check.call).to be_empty }
+    end
+
+    context "when Twitter authentication appears not to work" do
+      before do
+        authenticator.stubs(:enabled?).returns(true)
+        authenticator.stubs(:healthy?).returns(false)
+        Discourse.stubs(:base_path).returns("foo.bar")
+      end
+
+      it do
+        expect(problem_check.call).to contain_exactly(
+          have_attributes(
+            identifier: :twitter_login,
+            priority: "high",
+            message:
+              'Twitter login appears to not be working at the moment. Check the credentials in <a href="foo.bar/admin/site_settings/category/login?filter=twitter">the Site Settings</a>.',
+          ),
+        )
+      end
+    end
+  end
+end

spec/lib/problem_check_spec.rb

@@ -26,11 +26,12 @@ RSpec.describe ProblemCheck do
   end
 
   describe ".checks" do
-    it { expect(described_class.checks).to contain_exactly(scheduled_check, unscheduled_check) }
+    it { expect(described_class.checks).to include(scheduled_check, unscheduled_check) }
   end
 
   describe ".scheduled" do
-    it { expect(described_class.scheduled).to contain_exactly(scheduled_check) }
+    it { expect(described_class.scheduled).to include(scheduled_check) }
+    it { expect(described_class.scheduled).not_to include(unscheduled_check) }
   end
 
   describe ".scheduled?" do