Add tests

test/instance.js

@@ -0,0 +1,34 @@
+import test from 'ava';
+
+// Spoof supports-color
+require('./_supports-color')(__dirname);
+
+const chalk = require('..');
+
+test('create an isolated context where colors can be disabled (by level)', t => {
+	const instance = new chalk.instance({level: 0, enabled: true});
+	t.is(instance.red('foo'), 'foo');
+	t.is(chalk.red('foo'), '\u001B[31mfoo\u001B[39m');
+	instance.level = 2;
+	t.is(instance.red('foo'), '\u001B[31mfoo\u001B[39m');
+});
+
+test('create an isolated context where colors can be disabled (by enabled flag)', t => {
+	const instance = new chalk.instance({enabled: false});
+	t.is(instance.red('foo'), 'foo');
+	t.is(chalk.red('foo'), '\u001B[31mfoo\u001B[39m');
+	instance.enabled = true;
+	t.is(instance.red('foo'), '\u001B[31mfoo\u001B[39m');
+});
+
+test('the `level` option should be a number from 0 to 3', t => {
+	/* eslint-disable no-new */
+	t.throws(() => {
+		new chalk.instance({level: 10});
+	}, /should be an integer from 0 to 3/);
+
+	t.throws(() => {
+		new chalk.instance({level: -1});
+	}, /should be an integer from 0 to 3/);
+	/* eslint-enable no-new */
+});