Add test for default case

tests/default.js

@@ -0,0 +1,50 @@
+/*
+Night Theme Switcher Gnome Shell extension
+
+Copyright (C) 2020 Romain Vigier
+
+This program is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http s ://www.gnu.org/licenses/>.
+*/
+
+const test = require('ava');
+const { Variants } = require('./_variants');
+
+test('default', t => {
+	const variants = Variants.guess_from('default');
+	t.is(variants.day, 'default');
+	t.is(variants.night, 'default-dark');
+});
+
+test('default-dark', t => {
+	const variants = Variants.guess_from('default-dark');
+	t.is(variants.day, 'default');
+	t.is(variants.night, 'default-dark');
+});
+
+test('default-light', t => {
+	const variants = Variants.guess_from('default-light');
+	t.is(variants.day, 'default-light');
+	t.is(variants.night, 'default-dark');
+});
+
+test('default-darker', t => {
+	const variants = Variants.guess_from('default-darker');
+	t.is(variants.day, 'default-darker');
+	t.is(variants.night, 'default-dark');
+});
+
+test('default-darkest', t => {
+	const variants = Variants.guess_from('default-darkest');
+	t.is(variants.day, 'default');
+	t.is(variants.night, 'default-darkest');
+});