add basic test to make sure handler is registered

spec/requests/reports_spec.rb

@@ -0,0 +1,25 @@
+require "rails_helper"
+
+RSpec.describe "Reports" do
+  let(:user) { create :user }
+  let(:report_body) {
+    <<-EOF
+      {
+      "@context":"https://www.w3.org/ns/activitystreams",
+        "id":"https://mastodon.me.uk/d977f377-214b-4efd-8a47-70a37fb7ea20",
+        "type":"Flag",
+        "actor":"https://mastodon.me.uk/actor",
+        "content":"Test, please ignore",
+        "object":[
+          "https://example.com/models/abc123"
+        ]
+      }
+    EOF
+  }
+
+  it "should call registered Report handler when a flag is received by Federails" do
+    expect(Report).to receive(:handle_flag).once.and_call_original
+    post user.actor.inbox_url, params: report_body, headers: { content_type: "application/activity" }
+  end
+
+end