flags: raise flag limits.

The old flag limits were:

* 1 flag per day for regular members.
* 10 flags per day for Gold users.
* Unlimited flags for approvers.

The new flag limits are:

* 10 flags in the modqueue at once for regular users.
* Unlimited flags for approvers.
* Unlimited flags for users with a high enough flag success rate. If you
  have at least 30 flags in the last 3 months, and you have at least a
  70% flag success rate, then you get unlimited flags.

10 flags at once means you can have up to 10 flagged posts in the
modqueue at the same time. Because flags stay in the modqueue for 3
days, this means you can flag on average 10 posts every 3 days, or just
over 3 posts per day.

test/unit/post_approval_test.rb

@@ -3,64 +3,36 @@ require 'test_helper'
 class PostApprovalTest < ActiveSupport::TestCase
   context "a pending post" do
     setup do
-      @user = FactoryBot.create(:user, created_at: 2.weeks.ago)
-      CurrentUser.user = @user
-      CurrentUser.ip_addr = "127.0.0.1"
-
-      @post = FactoryBot.create(:post, uploader_id: @user.id, tag_string: "touhou", is_pending: true)
-
-      @approver = FactoryBot.create(:user)
-      @approver.can_approve_posts = true
-      @approver.save
-      CurrentUser.user = @approver
-
-      CurrentUser.stubs(:can_approve_posts?).returns(true)
-    end
-
-    teardown do
-      CurrentUser.user = nil
-      CurrentUser.ip_addr = nil
+      @user = create(:user, created_at: 2.weeks.ago)
+      @post = create(:post, uploader: @user, is_pending: true)
+      @approver = create(:user, can_approve_posts: true)
     end
 
     context "That is approved" do
       should "create a postapproval record" do
         assert_difference("PostApproval.count") do
-          @post.approve!
+          @post.approve!(@approver)
         end
       end
 
-      context "that is then flagged" do
-        setup do
-          @user2 = create(:user, created_at: 2.weeks.ago)
-          @user3 = create(:user, created_at: 2.weeks.ago)
-          @approver2 = FactoryBot.create(:user)
-          @approver2.can_approve_posts = true
-          @approver2.save
-        end
+      should "prevent an approver from approving the same post twice" do
+        @approval1 = create(:post_approval, post: @post, user: @approver)
+        @approval2 = build(:post_approval, post: @post, user: @approver)
 
-        should "prevent the first approver from approving again" do
-          @post.approve!(@approver)
-          CurrentUser.user = @user2
-          @post.flag!("blah")
-          @post.approve!(@approver2)
-          assert_not_equal(@approver.id, @post.approver_id)
-          CurrentUser.user = @user3
-          travel(PostFlag::COOLDOWN_PERIOD + 1.minute) do
-            @post.flag!("blah blah")
-          end
-
-          approval = @post.approve!(@approver)
-          assert_includes(approval.errors.full_messages, "You have previously approved this post and cannot approve it again")
-        end
+        assert_equal(false, @approval2.valid?)
+        assert_equal(["You have previously approved this post and cannot approve it again"], @approval2.errors[:base])
       end
     end
 
     context "#search method" do
       should "work" do
-        @approval = @post.approve!(@approver)
-        @approvals = PostApproval.search(user_name: @approver.name, post_tags_match: "touhou", post_id: @post.id)
+        CurrentUser.scoped(@approver) do
+          @post.update!(tag_string: "touhou")
+          @approval = @post.approve!(@approver)
+          @approvals = PostApproval.search(user_name: @approver.name, post_tags_match: "touhou", post_id: @post.id)
 
-        assert_equal([@approval.id], @approvals.map(&:id))
+          assert_equal([@approval.id], @approvals.map(&:id))
+        end
       end
     end
   end