Added tape class

src/classes/query.class.js

@@ -15,7 +15,10 @@ class Query {
 
     this.executed = false;
     this.success = null;
+
     this.rows = null;
+    this.response = null;
+
     this.err = null;
 
     this._onsuccess = null;
@@ -57,7 +60,6 @@ class Query {
    * - returns `true` if successful; `false` otherwise
    *
    * @returns {Promise.<boolean>} success
-   * @memberof Query
    */
   async execute() {
     if (!this.canExecute) throw new Error('This query cannot be executed yet');
@@ -65,13 +67,16 @@ class Query {
     return new Promise(resolve => {
       this._db.query(this.query, this.data, (err, res) => {
         this.executed = true;
+        this.response = res;
 
         if (err) {
           this.success = false;
           this.err = err;
+
           resolve(false);
         } else {
           this.rows = res.rows;
+          this.success = true;
 
           if (this._onsuccess instanceof Function) {
             this._onsuccess();

src/classes/query.specific.class.js

@@ -19,7 +19,6 @@ class SpecificQuery extends Query {
    *
    * @param {Database} db
    * @param {String} table
-   * @memberof SpecificQuery
    */
   constructor(db, table) {
     super(db);

src/classes/tape.class.js

+/** @typedef {import("./query.class")} Query */
+/** @typedef {import("./query.generic.class")} GenericQuery */
+/** @typedef {import("../database.class")} Database */
+
+class Tape {
+  /**
+   * Creates an instance of Tape.
+   * @param {Database} db
+   */
+  constructor(db) {
+    this._db = db;
+    /** @type {Array.<Query>} */
+    this.commands = [];
+  }
+
+  /**
+   * Records a new command to the tape
+   * @param {Query} query
+   */
+  add(query) {
+    this.commands.push(query);
+    return this;
+  }
+
+  /**
+   * Builds the query
+   * @returns {GenericQuery} query
+   */
+  build() {
+    return this._db.query(this.commands.map(item => item.query).join(';\n'));
+  }
+}
+
+module.exports = Tape;

src/database.class.js

@@ -4,6 +4,7 @@ const Select = require('./classes/select.class');
 const Insert = require('./classes/insert.class');
 const Delete = require('./classes/delete.class');
 const Update = require('./classes/update.class');
+const Tape = require('./classes/tape.class');
 
 /**
  * Class for communication with PostgreSQL database
@@ -22,7 +23,6 @@ class Database {
    */
   constructor({ host, port, database, user, password }) {
     this._db = new Pool({ host, port, database, user, password });
-    this._transaction = false;
   }
 
   /**
@@ -39,7 +39,7 @@ class Database {
    *
    * @param {String} query
    * @param {Array.<any>} data
-   * @returns {Query} query
+   * @returns {GenericQuery} query
    */
   query(query, data = []) {
     return new GenericQuery(this, query, data);
@@ -80,7 +80,6 @@ class Database {
    *
    * @param {String} table
    * @returns {Update} update
-   * @memberof Database
    */
   update(table) {
     return new Update(this, table);
@@ -92,11 +91,7 @@ class Database {
    * @returns {Promise.<GenericQuery>} success
    */
   begin() {
-    if (this._transaction) {
-      throw new Error('A transaction is already active');
-    }
-
-    return this.query('BEGIN').onsuccess(() => (this._transaction = true));
+    return this.query('BEGIN');
   }
 
   /**
@@ -105,11 +100,16 @@ class Database {
    * @returns {Promise.<GenericQuery>} success
    */
   commit() {
-    if (!this._transaction) {
-      throw new Error('No transaction is active');
-    }
+    return this.query('COMMIT');
+  }
 
-    return this.query('COMMIT').onsuccess(() => (this._transaction = false));
+  /**
+   * Creates and returns a new `Tape` instance
+   *
+   * @returns {Tape} tape
+   */
+  tape() {
+    return new Tape(this);
   }
 }
 

tests/test.js

@@ -65,9 +65,34 @@ const update = async () => {
 };
 
 (async () => {
-  await select();
-  await update();
-  await select();
+  // await select();
+  // await update();
+  // await select();
+
+  const query = db
+    .tape()
+    .add(db.begin())
+    .add(
+      db
+        .update('lorem')
+        .set({ foo: 'Updated Čau', bar: 420 })
+        .where({ id: 4 })
+    )
+    .add(
+      db.insert('lorem').values([
+        { foo: 'Ahoj', bar: 12 },
+        { foo: 'Čau', bar: 52 }
+      ])
+    )
+    .add(db.select('lorem').columns('*'))
+    .add(db.commit())
+    .build();
+
+  if (await query.execute()) {
+    console.log(query.response);
+  } else {
+    console.log(query.err);
+  }
 
   process.exit();
 })();