Upload 4.7

part4/bloglist/.eslintrc.js

@@ -2,7 +2,8 @@ module.exports = {
   'env': {
     'node': true,
     'commonjs': true,
-    'es2021': true
+    'es2021': true,
+    'jest': true
   },
   'extends': 'eslint:recommended',
   'overrides': [

part4/bloglist/package.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "start": "node index.js",
-    "test": "echo \"Error: no test specified\" && exit 1",
+    "test": "jest --verbose",
     "dev": "nodemon index.js"
   },
   "author": "",
@@ -14,6 +14,7 @@
     "cors": "^2.8.5",
     "dotenv": "^16.1.1",
     "express": "^4.18.2",
+    "jest": "^29.5.0",
     "mongoose": "^7.2.2"
   },
   "devDependencies": {

part4/bloglist/tests/list.test.js

@@ -0,0 +1,58 @@
+const listHelper = require('../utils/list_helper')
+
+const testBlogs = [
+  {
+    'title': 'My blog',
+    'author': 'Andrew',
+    'url': 'www.andrew.eu',
+    'likes': 1000,
+    'id': '64771b55a9c07824450982c5'
+  },
+  {
+    'title': 'My blog',
+    'author': 'Andrew',
+    'url': 'www.andrew.eu',
+    'likes': 3000,
+    'id': '64771b89a9c07824450982c8'
+  },
+  {
+    'title': 'Another blog 2',
+    'author': 'Hans',
+    'url': 'www.andrew.eu',
+    'likes': 5000,
+    'id': '64771caaa9c07824450982cb'
+  }
+]
+
+test('dummy returns one', () => {
+  const blogs = []
+
+  const result = listHelper.dummy(blogs)
+  expect(result).toBe(1)
+})
+
+describe('total likes', () => {
+  test('empty - zero', () => {
+    expect(listHelper.sumLikes([])).toBe(0)
+  })
+
+  test('one correct', () => {
+    expect(listHelper.sumLikes([testBlogs[0]])).toBe(1000)
+  })
+
+  test('sum correct', () => {
+    expect(listHelper.sumLikes(testBlogs)).toBe(9000)
+  })
+})
+
+test('favorite blog', () => {
+  expect(listHelper.favoriteBlog(testBlogs)).toEqual(testBlogs[2])
+})
+
+test('most blogs', () => {
+  expect(listHelper.mostBlogs(testBlogs)).toEqual({ author: 'Andrew', blogs: 2 })
+})
+
+test('most likes', () => {
+  expect(listHelper.mostLikes(testBlogs)).toEqual({ author: 'Hans', likes: 5000 })
+})

part4/bloglist/utils/list_helper.js

@@ -0,0 +1,37 @@
+const dummy = (blogs) => {
+  return 1
+}
+
+const sumLikes = (blogs) => {
+  return blogs.reduce((sum, blog) => sum + blog.likes, 0)
+}
+
+const favoriteBlog = (blogs) => {
+  return blogs.reduce((max, blog) => max.likes > blog.likes ? max : blog)
+}
+
+const mostBlogs = (blogs) => {
+  const authors = blogs.map(blog => blog.author)
+  const uniqueAuthors = [...new Set(authors)]
+  const authorBlogs = uniqueAuthors.map(author => {
+    return { author: author, blogs: authors.filter(a => a === author).length }
+  })
+  return authorBlogs.reduce((max, author) => max.blogs > author.blogs ? max : author)
+}
+
+const mostLikes = (blogs) => {
+  const authors = blogs.map(blog => blog.author)
+  const uniqueAuthors = [...new Set(authors)]
+  const authorLikes = uniqueAuthors.map(author => {
+    return { author: author, likes: blogs.filter(blog => blog.author === author).reduce((sum, blog) => sum + blog.likes, 0) }
+  })
+  return authorLikes.reduce((max, author) => max.likes > author.likes ? max : author)
+}
+
+module.exports = {
+  dummy,
+  sumLikes,
+  favoriteBlog,
+  mostBlogs,
+  mostLikes
+}