IE compatibility and add unit tests

test/unit/util.js

@@ -0,0 +1,30 @@
+/* eslint-env node, chai, mocha */
+require = require('esm')(module/*, options*/)
+const {expect} = require('chai')
+const {resolvePath} = require('../../src/core/router/util')
+
+describe('router/util', function () {
+  it('resolvePath', async function () {
+    // WHEN
+    const result = resolvePath('hello.md')
+
+    // THEN
+    expect(result).equal('/hello.md')
+  })
+
+  it('resolvePath with dot', async function () {
+    // WHEN
+    const result = resolvePath('./hello.md')
+
+    // THEN
+    expect(result).equal('/hello.md')
+  })
+
+  it('resolvePath with two dots', async function () {
+    // WHEN
+    const result = resolvePath('test/../hello.md')
+
+    // THEN
+    expect(result).equal('/hello.md')
+  })
+})