Count all URLs in text as 23 characters flat, do not count domain part of usernames (#4427)

* Count all URLs in text as 23 characters flat, do not count domain part of usernames

* Add new status text counting logic to web UI

spec/validators/status_length_validator_spec.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe StatusLengthValidator do
+  describe '#validate' do
+    it 'does not add errors onto remote statuses'
+    it 'does not add errors onto local reblogs'
+
+    it 'adds an error when content warning is over 500 characters' do
+      status = double(spoiler_text: 'a' * 520, text: '', errors: double(add: nil), local?: true, reblog?: false)
+      subject.validate(status)
+      expect(status.errors).to have_received(:add)
+    end
+
+    it 'adds an error when text is over 500 characters' do
+      status = double(spoiler_text: '', text: 'a' * 520, errors: double(add: nil), local?: true, reblog?: false)
+      subject.validate(status)
+      expect(status.errors).to have_received(:add)
+    end
+
+    it 'adds an error when text and content warning are over 500 characters total' do
+      status = double(spoiler_text: 'a' * 250, text: 'b' * 251, errors: double(add: nil), local?: true, reblog?: false)
+      subject.validate(status)
+      expect(status.errors).to have_received(:add)
+    end
+
+    it 'counts URLs as 23 characters flat' do
+      text   = ('a' * 476) + " http://#{'b' * 30}.com/example"
+      status = double(spoiler_text: '', text: text, errors: double(add: nil), local?: true, reblog?: false)
+
+      subject.validate(status)
+      expect(status.errors).to_not have_received(:add)
+    end
+
+    it 'counts only the front part of remote usernames' do
+      text   = ('a' * 475) + " @alice@#{'b' * 30}.com"
+      status = double(spoiler_text: '', text: text, errors: double(add: nil), local?: true, reblog?: false)
+
+      subject.validate(status)
+      expect(status.errors).to_not have_received(:add)
+    end
+  end
+end