1 files changed, 48 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/utils/tests/memoize.spec.js b/devtools/client/debugger/src/utils/tests/memoize.spec.js
new file mode 100644
index 0000000000..fb72958516
--- /dev/null
+++ b/devtools/client/debugger/src/utils/tests/memoize.spec.js
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */
+
+import memoize from "../memoize";
+
+const a = { number: 3 };
+const b = { number: 4 };
+const c = { number: 5 };
+const d = { number: 6 };
+
+function add(...numberObjects) {
+  return numberObjects.reduce((prev, cur) => prev + cur.number, 0);
+}
+
+describe("memozie", () => {
+  it("should work for one arg as key", () => {
+    const mAdd = memoize(add);
+    mAdd(a);
+    expect(mAdd(a)).toEqual(3);
+    mAdd(b);
+    expect(mAdd(b)).toEqual(4);
+  });
+
+  it("should only be called once", () => {
+    const spy = jest.fn(() => 2);
+    const mAdd = memoize(spy);
+
+    mAdd(a);
+    mAdd(a);
+    mAdd(a);
+    expect(spy).toHaveBeenCalledTimes(1);
+  });
+
+  it("should work for two args as key", () => {
+    const mAdd = memoize(add);
+    expect(mAdd(a, b)).toEqual(7);
+    expect(mAdd(a, b)).toEqual(7);
+    expect(mAdd(a, c)).toEqual(8);
+  });
+
+  it("should work with many args as key", () => {
+    const mAdd = memoize(add);
+    expect(mAdd(a, b, c)).toEqual(12);
+    expect(mAdd(a, b, d)).toEqual(13);
+    expect(mAdd(a, b, c)).toEqual(12);
+  });
+});