Added serve command test

Author: raphaelokon

test/serve.test.js

@@ -0,0 +1,25 @@
+const proxyquire = require('proxyquire');
+const tap = require('tap');
+const _ = require('lodash');
+const resolveConfig = require('../bin/resolve_config');
+const browserSyncMock = require('./mocks/browsersync.mock.js');
+const wrapAsync = require('../bin/utils').wrapAsync;
+
+// Require serve but mock patternlab so that we only test the module behavior
+const serve = proxyquire('../bin/serve', {'browser-sync': browserSyncMock});
+
+tap.test('Serve ->', t => wrapAsync(function*() {
+	const config = yield resolveConfig('./test/fixtures/patternlab-config.json');
+	config.paths.source.root = undefined;
+	t.throws(() => { serve(); }, {}, 'throws when config is empty');
+	t.throws(() => { serve(123); }, {}, 'throws when config is not of type object');
+	t.throws(() => {
+		_.unset(config, 'paths.source.root');
+		serve(config);
+	}, {}, 'throws when no source root dir is set on config');
+	t.throws(() => {
+		_.unset(config, 'paths.public.root');
+		serve(config);
+	}, {}, 'throws when no public root dir is set on config');
+	t.end();
+}));