#3 Added queues for multi queries support

__tests__/queue.spec.ts

@@ -0,0 +1,96 @@
+import Sphinxql from '../src/Sphinxql';
+import Queue from '../src/Queue';
+import BaseStatement from '../src/Statements/BaseStatement';
+
+describe('Tests for Queue class', () => {
+
+  const sphql = Sphinxql.createConnection({
+    host: 'localhost',
+    port: 9307,
+    multipleStatements: true,
+  });
+
+  afterAll(() => {
+    sphql.getConnection().close();
+  })
+
+  test('create an empty queue', () => {  
+    const queue = new Queue(sphql.getConnection());
+
+    expect(queue.empty()).toBeTruthy();
+  });
+
+  test('push multiple statements', () => {
+    const queue = new Queue(sphql.getConnection());
+
+    queue.push(sphql.getQueryBuilder().select('*').from('rt'));
+    queue.push(sphql.getQueryBuilder().select('*').from('rt'));
+
+    expect(queue.empty()).toBeFalsy();
+    expect(queue.size()).toBe(2);
+  });
+
+  test('shift statements', () => {
+    const queue = new Queue(sphql.getConnection());
+
+    queue.push(sphql.getQueryBuilder().select('*').from('rt'));
+    queue.push(sphql.getQueryBuilder().select('*').from('rt'));
+
+    expect(queue.empty()).toBeFalsy();
+    expect(queue.size()).toBe(2);
+
+    expect(queue.shift()).toBeInstanceOf(BaseStatement);
+    expect(queue.empty()).toBeFalsy();
+    expect(queue.size()).toBe(1);
+    expect(queue.shift()).toBeInstanceOf(BaseStatement);
+    expect(queue.empty()).toBeTruthy();
+    expect(queue.size()).toBe(0);
+  });
+
+  test('join query statements with a semicolon separator', () => {
+    const queue = new Queue(sphql.getConnection());
+
+    queue.push(sphql.getQueryBuilder().select('*').from('rt'));
+    queue.push(sphql.getQueryBuilder().select('*').from('rt'));
+
+    const result = queue.joinQueries();
+    const expected = "SELECT * FROM rt;SELECT * FROM rt";
+    expect(result).toBe(expected);
+  });
+
+  test('process multi query statements', (done) => {
+    const queue = new Queue(sphql.getConnection());
+
+    queue
+      .push(sphql.getQueryBuilder().select('*').from('rt'))
+      .push(sphql.getQueryBuilder().select('*').from('rt'))
+      .push(sphql.getQueryBuilder().select('*').from('rt'));
+
+    queue.process()
+      .then((results) => {
+        expect(results.results).toHaveLength(3);
+
+        done();
+      })
+      .catch((error) => {
+        console.log(error);
+        done();
+      });
+  });
+
+  test('process empty queue with rejected promise with an Error', (done) => {
+    const queue = new Queue(sphql.getConnection());
+
+    queue.process()
+      .then((results) => {
+        expect(results.results).toHaveLength(3);
+
+        done();
+      })
+      .catch((error) => {
+        expect(error).toBeInstanceOf(Error);
+        expect(error.message).not.toHaveLength(0);
+        done();
+      });
+  });
+});