FIX: Validate number of votes allowed per poll per user. (#15001)

* DEV: Remove spec that we no longer need.

As far as we know, the migration has been successful for a number of
years.

* FIX: Validate number of votes allowed per poll per user.

plugins/poll/spec/lib/poll_spec.rb

@@ -0,0 +1,131 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe DiscoursePoll::Poll do
+  fab!(:user) { Fabricate(:user) }
+  fab!(:user_2) { Fabricate(:user) }
+
+  fab!(:post_with_regular_poll) do
+    Fabricate(:post, raw: <<~RAW)
+      [poll]
+      * 1
+      * 2
+      [/poll]
+    RAW
+  end
+
+  fab!(:post_with_multiple_poll) do
+    Fabricate(:post, raw: <<~RAW)
+      [poll type=multiple min=2 max=3]
+      * 1
+      * 2
+      * 3
+      * 4
+      * 5
+      [/poll]
+    RAW
+  end
+
+  describe '.vote' do
+    it 'should only allow one vote per user for a regular poll' do
+      poll = post_with_regular_poll.polls.first
+
+      expect do
+        DiscoursePoll::Poll.vote(
+          user,
+          post_with_regular_poll.id,
+          "poll",
+          poll.poll_options.map(&:digest)
+        )
+      end.to raise_error(DiscoursePoll::Error, I18n.t("poll.one_vote_per_user"))
+    end
+
+    it 'should clean up bad votes for a regular poll' do
+      poll = post_with_regular_poll.polls.first
+
+      PollVote.create!(
+        poll: poll,
+        poll_option: poll.poll_options.first,
+        user: user
+      )
+
+      PollVote.create!(
+        poll: poll,
+        poll_option: poll.poll_options.last,
+        user: user
+      )
+
+      DiscoursePoll::Poll.vote(
+        user,
+        post_with_regular_poll.id,
+        "poll",
+        [poll.poll_options.first.digest]
+      )
+
+      expect(PollVote.where(poll: poll, user: user).pluck(:poll_option_id))
+        .to contain_exactly(poll.poll_options.first.id)
+    end
+
+    it 'allows user to vote on multiple options correctly for a multiple poll' do
+      poll = post_with_multiple_poll.polls.first
+      poll_options = poll.poll_options
+
+      [
+        poll_options.first,
+        poll_options.second,
+        poll_options.third,
+      ].each do |poll_option|
+        PollVote.create!(poll: poll, poll_option: poll_option, user: user)
+      end
+
+      DiscoursePoll::Poll.vote(
+        user,
+        post_with_multiple_poll.id,
+        "poll",
+        [poll_options.first.digest, poll_options.second.digest]
+      )
+
+      DiscoursePoll::Poll.vote(
+        user_2,
+        post_with_multiple_poll.id,
+        "poll",
+        [poll_options.third.digest, poll_options.fourth.digest]
+      )
+
+      expect(PollVote.where(poll: poll, user: user).pluck(:poll_option_id))
+        .to contain_exactly(poll_options.first.id, poll_options.second.id)
+
+      expect(PollVote.where(poll: poll, user: user_2).pluck(:poll_option_id))
+        .to contain_exactly(poll_options.third.id, poll_options.fourth.id)
+    end
+
+    it 'should respect the min/max votes per user for a multiple poll' do
+      poll = post_with_multiple_poll.polls.first
+
+      expect do
+        DiscoursePoll::Poll.vote(
+          user,
+          post_with_multiple_poll.id,
+          "poll",
+          poll.poll_options.map(&:digest)
+        )
+      end.to raise_error(
+        DiscoursePoll::Error,
+        I18n.t("poll.max_vote_per_user", count: poll.max)
+      )
+
+      expect do
+        DiscoursePoll::Poll.vote(
+          user,
+          post_with_multiple_poll.id,
+          "poll",
+          [poll.poll_options.first.digest]
+        )
+      end.to raise_error(
+        DiscoursePoll::Error,
+        I18n.t("poll.min_vote_per_user", count: poll.min)
+      )
+    end
+  end
+end