Add reminders for overdue tasks (#832)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/832
Co-authored-by: konrad <konrad@kola-entertainments.de>
Co-committed-by: konrad <konrad@kola-entertainments.de>

pkg/models/task_overdue_reminder_test.go

@@ -0,0 +1,62 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2021 Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public Licensee as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public Licensee for more details.
+//
+// You should have received a copy of the GNU Affero General Public Licensee
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package models
+
+import (
+	"testing"
+	"time"
+
+	"code.vikunja.io/api/pkg/db"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetUndoneOverDueTasks(t *testing.T) {
+	t.Run("no undone tasks", func(t *testing.T) {
+		db.LoadAndAssertFixtures(t)
+		s := db.NewSession()
+		defer s.Close()
+
+		now, err := time.Parse(time.RFC3339Nano, "2018-01-01T01:13:00Z")
+		assert.NoError(t, err)
+		taskIDs, err := getUndoneOverdueTasks(s, now)
+		assert.NoError(t, err)
+		assert.Len(t, taskIDs, 0)
+	})
+	t.Run("undone overdue", func(t *testing.T) {
+		db.LoadAndAssertFixtures(t)
+		s := db.NewSession()
+		defer s.Close()
+
+		now, err := time.Parse(time.RFC3339Nano, "2018-12-01T01:13:00Z")
+		assert.NoError(t, err)
+		taskIDs, err := getUndoneOverdueTasks(s, now)
+		assert.NoError(t, err)
+		assert.Len(t, taskIDs, 1)
+		assert.Equal(t, int64(6), taskIDs[0])
+	})
+	t.Run("done overdue", func(t *testing.T) {
+		db.LoadAndAssertFixtures(t)
+		s := db.NewSession()
+		defer s.Close()
+
+		now, err := time.Parse(time.RFC3339Nano, "2018-11-01T01:13:00Z")
+		assert.NoError(t, err)
+		taskIDs, err := getUndoneOverdueTasks(s, now)
+		assert.NoError(t, err)
+		assert.Len(t, taskIDs, 0)
+	})
+}