fix example bugs

Author: codimiracle

README.md

@@ -24,7 +24,7 @@ set.add({ id: '1', value: 1 });
 set.add({ id: '2', value: 2 });
 set.add({ id: '1', value: 3 });
 
-console.log(set.toArray()); // [{ id: '1', value: 3 }, { id: '2', value: 2 }
+console.log(set.toArray()); // [{ id: '1', value: 3 }, { id: '2', value: 2 }]
 ```
 
 2. change identifier of element
@@ -45,7 +45,7 @@ set.add({ key: '1', value: 1 });
 set.add({ key: '2', value: 2 });
 set.add({ key: '1', value: 3 });
 
-console.log(set.toArray()); // [{ key: '1', value: 3 }, { key: '2', value: 2 }
+console.log(set.toArray()); // [{ key: '1', value: 3 }, { key: '2', value: 2 }]
 ```
 
 3. custom refresh method
@@ -60,15 +60,16 @@ type Element = {
 const set = new RefreshSet<Element>({
   policy: RefreshPolicy.MERGER,
   merger: (oldElement, newElement) => {
-    newElement.value = oldElement.value + 1;
+    newElement.value = oldElement.value + newElement.value;
+    return newElement;
   },
 });
 
 set.add({ id: '1', value: 1 });
 set.add({ id: '2', value: 2 });
 set.add({ id: '1', value: 3 });
 
-console.log(set.toArray()); // [{ id: '1', value: 4 }, { id: '2', value: 2 }
+console.log(set.toArray()); // [{ id: '1', value: 4 }, { id: '2', value: 2 }]
 ```
 
 ## contributing

tests/example.test.ts

@@ -0,0 +1,62 @@
+import { RefreshPolicy, RefreshSet } from "../src";
+
+describe("testExample1", () => {
+
+  type Element = {
+    id: string;
+    value: number;
+  };
+
+  const set = new RefreshSet<Element>();
+
+  set.add({ id: '1', value: 1 });
+  set.add({ id: '2', value: 2 });
+  set.add({ id: '1', value: 3 });
+
+  it('example 1 must be pass', () => {
+    expect(set.toArray()).toEqual([{ id: '1', value: 3 }, { id: '2', value: 2 }]);
+  });
+});
+
+describe("testExample2", () => {
+  type Element = {
+    key: string;
+    value: number;
+  };
+
+  // default id supplier is element.id
+  const set = new RefreshSet<Element>({
+    idSupplier: (element) => element.key,
+  });
+
+  set.add({ key: '1', value: 1 });
+  set.add({ key: '2', value: 2 });
+  set.add({ key: '1', value: 3 });
+
+  it('example 2 must be pass', () => {
+    expect(set.toArray()).toEqual([{ key: '1', value: 3 }, { key: '2', value: 2 }]);
+  });
+});
+
+describe("testExample3", () => {
+  type Element = {
+    id: string;
+    value: number;
+  };
+
+  const set = new RefreshSet<Element>({
+    policy: RefreshPolicy.MERGER,
+    merger: (oldElement, newElement) => {
+      newElement.value = oldElement.value + newElement.value;
+      return newElement;
+    },
+  });
+
+  set.add({ id: '1', value: 1 });
+  set.add({ id: '2', value: 2 });
+  set.add({ id: '1', value: 3 });
+
+  it('example 3 must be pass', () => {
+    expect(set.toArray()).toEqual([{ id: '1', value: 4 }, { id: '2', value: 2 }]);
+  });
+});