Page model (#1)

* Initial database and page MVC

* Add mocha tests

* Add docs

* Add docs about nedb query options

* Add eslint and editorconfig + husky

* Improve precommit script

* Remove unnecessary dependencies

controllers/pages.js

@@ -0,0 +1,106 @@
+const Model = require('../models/page');
+
+/**
+ * @class Pages
+ * @classdesc Pages controller
+ */
+class Pages {
+  /**
+   * @static
+   * Fields required for page model creation
+   *
+   * @returns {['title', 'body']}
+   */
+  static get REQUIRED_FIELDS() {
+    return ['title', 'body'];
+  }
+
+  /**
+   * @static
+   * Find and return page model with passed id
+   *
+   * @param {string} id - page id
+   * @returns {Promise<Page>}
+   */
+  static async get(id) {
+    const page = await Model.get(id);
+
+    if (!page._id) {
+      throw new Error('Page with given id does not exist');
+    }
+
+    return page;
+  }
+
+  /**
+   * Return all pages
+   *
+   * @returns {Promise<Page[]>}
+   */
+  static async getAll() {
+    return Model.getAll();
+  }
+
+  /**
+   * Create new page model and save it in the database
+   *
+   * @param {PageData} data
+   * @returns {Promise<Page>}
+   */
+  static async insert(data) {
+    if (!Pages.validate(data)) {
+      throw new Error('Invalid request format');
+    }
+
+    const page = new Model(data);
+
+    return page.save();
+  }
+
+  /**
+   * Check PageData object for required fields
+   *
+   * @param {PageData} data
+   * @returns {boolean}
+   */
+  static validate(data) {
+    return Pages.REQUIRED_FIELDS.every(field => typeof data[field] !== 'undefined');
+  }
+
+  /**
+   * Update page with given id in the database
+   *
+   * @param {string} id - page id
+   * @param {PageData} data
+   * @returns {Promise<Page>}
+   */
+  static async update(id, data) {
+    const page = await Model.get(id);
+
+    if (!page._id) {
+      throw new Error('Page with given id does not exist');
+    }
+
+    page.data = data;
+
+    return page.save();
+  }
+
+  /**
+   * Remove page with given id from the database
+   *
+   * @param {string} id - page id
+   * @returns {Promise<Page>}
+   */
+  static async remove(id) {
+    const page = await Model.get(id);
+
+    if (!page._id) {
+      throw new Error('Page with given id does not exist');
+    }
+
+    return page.destroy();
+  }
+}
+
+module.exports = Pages;