Copy tests from the polyfill

packages/@ember/-internals/metal/tests/tracked/storage_test.js

@@ -0,0 +1,85 @@
+import { createCache, getValue as getCacheValue } from '../../lib/cache';
+
+import { createStorage, getValue, setValue } from '../../lib/storage';
+
+import { moduleFor, AbstractTestCase } from 'internal-test-helpers';
+
+moduleFor(
+  '@ember/-internals/metal/storage',
+  class extends AbstractTestCase {
+    ['@test it works'](assert) {
+      let count = 0;
+
+      let storage = createStorage();
+
+      let cache = createCache(() => {
+        getValue(storage);
+        return ++count;
+      });
+
+      assert.equal(getValue(storage), undefined, 'does not have a value initially');
+      assert.equal(getCacheValue(cache), 1, 'cache runs the first time');
+      assert.equal(getCacheValue(cache), 1, 'cache does not the second time');
+
+      setValue(storage, 123);
+
+      assert.equal(getValue(storage), 123, 'value is set correctly');
+      assert.equal(getCacheValue(cache), 2, 'cache ran after storage was set');
+
+      setValue(storage, 123);
+
+      assert.equal(getValue(storage), 123, 'value remains the same');
+      assert.equal(getCacheValue(cache), 2, 'cache not ran after storage was set to same value');
+    }
+
+    ['@test it can set an initial value'](assert) {
+      let count = 0;
+
+      let storage = createStorage(123);
+
+      let cache = createCache(() => {
+        getValue(storage);
+        return ++count;
+      });
+
+      assert.equal(getValue(storage), 123, 'has a initial value');
+      assert.equal(getCacheValue(cache), 1, 'cache runs the first time');
+      assert.equal(getCacheValue(cache), 1, 'cache does not the second time');
+
+      setValue(storage, 123);
+
+      assert.equal(getValue(storage), 123, 'value is not updated');
+      assert.equal(getCacheValue(cache), 1, 'cache not ran after storage was set to same value');
+
+      setValue(storage, 456);
+
+      assert.equal(getValue(storage), 456, 'value updated');
+      assert.equal(getCacheValue(cache), 2, 'cache ran after storage was set to different value');
+    }
+
+    ['@test it can set an equality function'](assert) {
+      let count = 0;
+
+      let storage = createStorage(123, () => false);
+
+      let cache = createCache(() => {
+        getValue(storage);
+        return ++count;
+      });
+
+      assert.equal(getValue(storage), 123, 'has a initial value');
+      assert.equal(getCacheValue(cache), 1, 'cache runs the first time');
+      assert.equal(getCacheValue(cache), 1, 'cache does not the second time');
+
+      setValue(storage, 123);
+
+      assert.equal(getValue(storage), 123, 'value is not updated');
+      assert.equal(getCacheValue(cache), 2, 'cache runs again');
+
+      setValue(storage, 456);
+
+      assert.equal(getValue(storage), 456, 'value updated');
+      assert.equal(getCacheValue(cache), 3, 'cache ran after storage was set to different value');
+    }
+  }
+);