feat: add transformations

Fixes #9

test/transformations/timestamp.spec.ts

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2019 StApps
+ * 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, version 3.
+ *
+ * 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 <https://www.gnu.org/licenses/>.
+ */
+import {expect} from 'chai';
+import {suite, test} from 'mocha-typescript';
+import {Timestamp} from '../../src/transformations/timestamp';
+import moment = require('moment');
+
+@suite()
+export class ColorizeSpec {
+  @test
+  'default'() {
+    const transformation = new Timestamp();
+
+    expect(transformation.transform('ERROR', 'Foobar')).to.be.equal(`[${moment().format('LLLL')}] Foobar`);
+  }
+
+  @test
+  'different format'() {
+    const transformation = new Timestamp('DD.MM.YYYY');
+
+    expect(transformation.transform('ERROR', 'Foobar')).to.be.equal(`[${moment().format('DD.MM.YYYY')}] Foobar`);
+  }
+}