Change query to work on mysql as well. Also set entire date because setting...

Change query to work on mysql as well. Also set entire date because setting only the year can trip 'start_date_should_be_less_than_due_date'

app/models/milestone.rb

@@ -58,6 +58,7 @@ class Milestone < ApplicationRecord
   validate :uniqueness_of_title, if: :title_changed?
   validate :milestone_type_check
   validate :start_date_should_be_less_than_due_date, if: proc { |m| m.start_date.present? && m.due_date.present? }
+  validate :dates_within_4_digits
 
   strip_attributes :title
 
@@ -326,6 +327,16 @@ class Milestone < ApplicationRecord
     end
   end
 
+  def dates_within_4_digits
+    if start_date && start_date > Date.new(9999, 12, 31)
+      errors.add(:start_date, _("date must not be after 9999-12-31"))
+    end
+
+    if due_date && due_date > Date.new(9999, 12, 31)
+      errors.add(:due_date, _("date must not be after 9999-12-31"))
+    end
+  end
+
   def issues_finder_params
     { project_id: project_id }
   end

changelogs/unreleased/add-constraint-for-milestone-dates.yml

+---
+title: Limit milestone dates to before year 9999
+merge_request: 28742
+author: Luke Picciau
+type: fixed

db/migrate/20190523112344_limit_milestone_date_years_to_4_digits.rb

+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class LimitMilestoneDateYearsTo4Digits < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  # When a migration requires downtime you **must** uncomment the following
+  # constant and define a short and easy to understand explanation as to why the
+  # migration requires downtime.
+  # DOWNTIME_REASON = ''
+
+  # When using the methods "add_concurrent_index", "remove_concurrent_index" or
+  # "add_column_with_default" you must disable the use of transactions
+  # as these methods can not run in an existing transaction.
+  # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
+  # that either of them is the _only_ method called in the migration,
+  # any other changes should go in a separate migration.
+  # This ensures that upon failure _only_ the index creation or removing fails
+  # and can be retried or reverted easily.
+  #
+  # To disable transactions uncomment the following line and remove these
+  # comments:
+  # disable_ddl_transaction!
+
+  def change
+    Milestone.where("start_date > '9999-12-31'").update_all(
+      "start_date = '9999-12-31'"
+    )
+    Milestone.where("due_date > '9999-12-31'").update_all(
+      "due_date = '9999-12-31'"
+    )
+  end
+end

locale/gitlab.pot

@@ -11991,6 +11991,9 @@ msgstr ""
 msgid "customize"
 msgstr ""
 
+msgid "date must not be after 9999-12-31"
+msgstr ""
+
 msgid "day"
 msgid_plural "days"
 msgstr[0] ""

spec/models/milestone_spec.rb

@@ -31,12 +31,28 @@ describe Milestone do
     end
 
     describe 'start_date' do
-      it 'adds an error when start_date is greated then due_date' do
+      it 'adds an error when start_date is greater then due_date' do
         milestone = build(:milestone, start_date: Date.tomorrow, due_date: Date.yesterday)
 
         expect(milestone).not_to be_valid
         expect(milestone.errors[:due_date]).to include("must be greater than start date")
       end
+
+      it 'adds an error when start_date is greater than 9999-12-31' do
+        milestone = build(:milestone, start_date: Date.new(10000, 1, 1))
+
+        expect(milestone).not_to be_valid
+        expect(milestone.errors[:start_date]).to include("date must not be after 9999-12-31")
+      end
+    end
+
+    describe 'due_date' do
+      it 'adds an error when due_date is greater than 9999-12-31' do
+        milestone = build(:milestone, due_date: Date.new(10000, 1, 1))
+
+        expect(milestone).not_to be_valid
+        expect(milestone.errors[:due_date]).to include("date must not be after 9999-12-31")
+      end
     end
   end
 
@@ -381,21 +397,6 @@ describe Milestone do
         expect(milestone_ids).to be_empty
       end
     end
-
-    context 'when there is a milestone with a date after 294276 AD', :postgresql do
-      before do
-        past_milestone_project_1.update!(due_date: Date.new(294277, 1, 1))
-      end
-
-      it 'returns the next upcoming open milestone ID for each project and group' do
-        expect(milestone_ids).to contain_exactly(
-          current_milestone_project_1.id,
-          current_milestone_project_2.id,
-          current_milestone_group_1.id,
-          current_milestone_group_2.id
-        )
-      end
-    end
   end
 
   describe '#to_reference' do