exercise 4.6 completed

parts/4/blogApp/tests/mostPosts.test.js

@@ -0,0 +1,54 @@
+const { test, describe } = require("node:test");
+const assert = require("node:assert");
+const { mostPosts } = require("../src/utils");
+
+describe("most posts ", () => {
+  const posts = [
+    {
+      _id: "5a422aa71b54a676234d17f8",
+      title: "Go To Statement Considered Harmful",
+      author: "Edsger W. Dijkstra",
+      url: "https://homepages.cwi.nl/~storm/teaching/reader/Dijkstra68.pdf",
+      likes: 5,
+      __v: 0,
+    },
+    {
+      _id: "5a422aa71b54a676234d17f8",
+      title: "Go To Statement Considered Harmful",
+      author: "Edsger W. Dijkstra",
+      url: "https://homepages.cwi.nl/~storm/teaching/reader/Dijkstra68.pdf",
+      likes: 2,
+      __v: 0,
+    },
+    {
+      _id: "123",
+      title: "Lololo",
+      author: "John Doe",
+      url: "https://homepages.cwi.nl/~storm/teaching/reader/Dijkstra68.pdf",
+      likes: 1,
+      __v: 0,
+    },
+  ];
+
+  const emptyArray = [];
+
+  const gibberish = "asdaSd123asd";
+
+  test("finds top author  properly", () => {
+    assert.deepStrictEqual(mostPosts(posts), {
+      author: "Edsger W. Dijkstra",
+      posts: 2,
+    });
+  });
+
+  test("works fine with empty array", () => {
+    assert.strictEqual(mostPosts(emptyArray), null);
+  });
+
+  test("fails with gibberish input", () => {
+    const failedCall = () => {
+      mostPosts(gibberish);
+    };
+    assert.throws(failedCall, Error);
+  });
+});