chore(xo-server/MultiKeyMap): add basic tests

packages/xo-server/src/_MultiKeyMap.spec.js

@@ -0,0 +1,34 @@
+/* eslint-env jest */
+
+import MultiKeyMap from './_MultiKeyMap'
+
+describe('MultiKeyMap', () => {
+  it('works', () => {
+    const map = new MultiKeyMap()
+
+    const keys = [
+      // null key
+      [],
+      // simple key
+      ['foo'],
+      // composite key
+      ['foo', 'bar'],
+      // reverse composite key
+      ['bar', 'foo'],
+    ]
+    const values = keys.map(() => ({}))
+
+    // set all values first to make sure they are all stored and not only the
+    // last one
+    keys.forEach((key, i) => {
+      map.set(key, values[i])
+    })
+
+    keys.forEach((key, i) => {
+      // copy the key to make sure the array itself is not the key
+      expect(map.get(key.slice())).toBe(values[i])
+      map.delete(key.slice())
+      expect(map.get(key.slice())).toBe(undefined)
+    })
+  })
+})