add optimizations tests

test/optimizations.ts

@@ -0,0 +1,36 @@
+import { getSnapshot, applySnapshot, unprotect, types } from "../src"
+import { test } from "ava"
+
+test("it should avoid processing patch if is exactly the current one in applySnapshot", t => {
+    let called = false
+    const Model = types.model({
+        a: types.number,
+        b: types.string
+    })
+
+    const store = Model.create({ a: 1, b: "hello" })
+    called = false
+
+    const snapshot = getSnapshot(store)
+    applySnapshot(store, snapshot)
+    t.is(getSnapshot(store), snapshot) // no new snapshot emitted
+})
+
+test("it should avoid processing patch if is exactly the current one in reconcile", t => {
+    const Model = types.model({
+        a: types.number,
+        b: types.string
+    })
+
+    const RootModel = types.model({
+        a: Model
+    })
+
+    const store = RootModel.create({ a: { a: 1, b: "hello" } })
+    unprotect(store)
+
+    const snapshot = getSnapshot(store)
+    store.a = snapshot.a
+    t.is(getSnapshot(store.a), snapshot.a)
+    t.deepEqual(getSnapshot(store), snapshot)
+})