completed exercise 4.7

parts/4/blogApp/package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "start": "node src/app.js",
     "dev": "node --watch src/app.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "node --test"
   },
   "author": "",
   "license": "ISC",

parts/4/blogApp/src/app.js

@@ -1,37 +1,12 @@
-const express = require('express')
-const mongoose = require('mongoose')
+const express = require("express");
+const { addRoutes } = require("./routes");
+const app = express();
 
-const app = express()
+app.use(express.json());
 
-const blogSchema = mongoose.Schema({
-  title: String,
-  author: String,
-  url: String,
-  likes: Number,
-})
+addRoutes(app);
 
-const Blog = mongoose.model('Blog', blogSchema)
-
-const mongoUrl = 'mongodb://localhost/bloglist'
-mongoose.connect(mongoUrl)
-
-app.use(express.json())
-
-app.get('/api/blogs', (request, response) => {
-  Blog.find({}).then((blogs) => {
-    response.json(blogs)
-  })
-})
-
-app.post('/api/blogs', (request, response) => {
-  const blog = new Blog(request.body)
-
-  blog.save().then((result) => {
-    response.status(201).json(result)
-  })
-})
-
-const PORT = 3003
+const PORT = 3003;
 app.listen(PORT, () => {
-  console.log(`Server running on port ${PORT}`)
-})
+  console.log(`Server running on port ${PORT}`);
+});

parts/4/blogApp/src/db.js

@@ -0,0 +1,15 @@
+const mongoose = require('mongoose')
+
+const blogSchema = mongoose.Schema({
+  title: String,
+  author: String,
+  url: String,
+  likes: Number,
+})
+
+const Blog = mongoose.model('Blog', blogSchema)
+
+const mongoUrl = 'mongodb://localhost/bloglist'
+mongoose.connect(mongoUrl)
+
+module.exports = {models: {Blog}}

parts/4/blogApp/src/routes.js

@@ -0,0 +1,22 @@
+const { models } = require("./db");
+const Blog = models.Blog;
+
+BASE_API_PATH = "/api";
+
+const addRoutes = (app) => {
+  app.get(`${BASE_API_PATH}/blogs`, (request, response) => {
+    Blog.find({}).then((blogs) => {
+      response.json(blogs);
+    });
+  });
+
+  app.post(`${BASE_API_PATH}/blogs`, (request, response) => {
+    const blog = new Blog(request.body);
+
+    blog.save().then((result) => {
+      response.status(201).json(result);
+    });
+  });
+};
+
+module.exports = { addRoutes };

parts/4/blogApp/src/utils.js

@@ -0,0 +1,89 @@
+const reverse = (string) => {
+  return string.split("").reverse().join("");
+};
+
+const average = (array) => {
+  const reducer = (sum, item) => {
+    return sum + item;
+  };
+
+  return array.length === 0 ? 0 : array.reduce(reducer, 0) / array.length;
+};
+
+const listHelper = (posts) => {
+  console.log("lol");
+  return 1;
+};
+
+const totalLikes = (posts) => {
+  if (!posts) {
+    return 0;
+  }
+
+  const likeCount = posts
+    .map((post) => post.likes)
+    .reduce((cum, value) => cum + value, 0);
+
+  return likeCount;
+};
+
+const favoritePost = (posts) => {
+  if (!posts || posts.length === 0) {
+    return null;
+  }
+
+  const highestLikes = posts.reduce(
+    (max, post) => (post.likes > max ? (max = post.likes) : max),
+    0
+  );
+
+  const favoritePost = posts.find((post) => post.likes == highestLikes);
+
+  return favoritePost;
+};
+
+const mostPosts = (posts) => {
+  if (!posts || posts.length === 0) {
+    return null;
+  }
+
+  const countMap = posts.reduce((acc, post) => {
+    acc[post.author] = (acc[post.author] || 0) + 1;
+    return acc;
+  }, {});
+
+  const [author, postsCount] = Object.entries(countMap).reduce(
+    (max, entry) => (entry[1] > max[1] ? entry : max),
+    ['', 0]
+  );
+
+  return { author, posts: postsCount };
+};
+
+const mostLikes = (posts) => {
+    if (!posts || posts.length === 0) {
+      return null;
+    }
+  
+    const likesMap = posts.reduce((acc, post) => {
+      acc[post.author] = (acc[post.author] || 0) + post.likes;
+      return acc;
+    }, {});
+  
+    const [author, likesCount] = Object.entries(likesMap).reduce(
+      (max, entry) => (entry[1] > max[1] ? entry : max),
+      ['', 0]
+    );
+  
+    return { author, likes: likesCount };
+  };
+
+module.exports = {
+  reverse,
+  average,
+  listHelper,
+  totalLikes,
+  favoritePost,
+  mostPosts,
+  mostLikes
+};

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

@@ -0,0 +1,18 @@
+const { test, describe } = require('node:test')
+const assert = require('node:assert')
+
+const average = require('../src/utils').average
+
+describe('average', () => {
+  test('of one value is the value itself', () => {
+    assert.strictEqual(average([1]), 1)
+  })
+
+  test('of many is calculated right', () => {
+    assert.strictEqual(average([1, 2, 3, 4, 5, 6]), 3.5)
+  })
+
+  test('of empty array is zero', () => {
+    assert.strictEqual(average([]), 0)
+  })
+})

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

@@ -0,0 +1,43 @@
+const { test, describe } = require("node:test");
+const assert = require("node:assert");
+const { favoritePost } = require("../src/utils");
+
+describe("favoritePost ", () => {
+  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,
+    },
+  ];
+
+  const emptyArray = [];
+
+  const gibberish = "asdaSd123asd";
+
+  test("finds top properly", () => {
+    assert.strictEqual(favoritePost(posts), posts[0]);
+  });
+
+  test("works fine with empty array", () => {
+    assert.strictEqual(favoritePost(emptyArray), null);
+  });
+
+  test("fails with gibberish input", () => {
+    const failedCall = () => {
+      favoritePost(gibberish);
+    };
+    assert.throws(failedCall, Error);
+  });
+});

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

@@ -0,0 +1,10 @@
+const { test, describe } = require("node:test");
+const assert = require("node:assert");
+const { listHelper } = require("../src/utils");
+
+test("dummy returns one", () => {
+  const blogs = [];
+
+  const result = listHelper(blogs);
+  assert.strictEqual(result, 1);
+});

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

@@ -0,0 +1,54 @@
+const { test, describe } = require("node:test");
+const assert = require("node:assert");
+const { mostLikes } = require("../src/utils");
+
+describe("most likes ", () => {
+  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(mostLikes(posts), {
+      author: "Edsger W. Dijkstra",
+      likes: 7,
+    });
+  });
+
+  test("works fine with empty array", () => {
+    assert.strictEqual(mostLikes(emptyArray), null);
+  });
+
+  test("fails with gibberish input", () => {
+    const failedCall = () => {
+      mostLikes(gibberish);
+    };
+    assert.throws(failedCall, Error);
+  });
+});

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);
+  });
+});

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

@@ -0,0 +1,22 @@
+const { test } = require('node:test')
+const assert = require('node:assert')
+
+const reverse = require('../src/utils.js').reverse
+
+test('reverse of a', () => {
+  const result = reverse('a')
+
+  assert.strictEqual(result, 'a')
+})
+
+test('reverse of react', () => {
+  const result = reverse('react')
+
+  assert.strictEqual(result, 'tcaer')
+})
+
+test('reverse of saippuakauppias', () => {
+  const result = reverse('saippuakauppias')
+
+  assert.strictEqual(result, 'saippuakauppias')
+})

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

@@ -0,0 +1,43 @@
+const { test, describe } = require("node:test");
+const assert = require("node:assert");
+const { totalLikes } = require("../src/utils");
+
+describe("total likes ", () => {
+  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,
+    },
+  ];
+
+  const emptyArray = [];
+
+  const gibberish = "asdaSd123asd";
+
+  test("counts likes properly", () => {
+    assert.strictEqual(totalLikes(posts), 7);
+  });
+
+  test("works fine with empty array", () => {
+    assert.strictEqual(totalLikes(emptyArray), 0);
+  });
+
+  test("fails with gibberish input", () => {
+    const failedCall = () => {
+      totalLikes(gibberish);
+    };
+    assert.throws(failedCall, Error);
+  });
+});

parts/4/notes.md

@@ -0,0 +1,8 @@
+Exercises:
+* [X] 4.1
+* [X] 4.2
+* [X] 4.3
+* [X] 4.4
+* [X] 4.5
+* [X] 4.6
+* [X] 4.7