Change API to use ECMAScript6

Major modifications:
- Source code is now in the src directory
- All source files were adapted to ECMAScript6
- Add Gulpfile and Babel to transcompile the project from ES6 to ES5 (until Node.js fully supports ES6)
	- By running gulp one generates the build directory with the files transcompiled, from which the API can be run
- Add ESLint to check for syntax errors and enforce code standards
	- Javascript coding standard currently adopted is AirBnB with 4 spaces
- Replace monetdb package with monetdb-pool, which allows for concurrent queries over a pool of connections while maintaining the same interface

TODO (in order of priority, from high to low):
- Add Gulp tasks to handle automatic building, tests and running the server in order to deprecate using npm
- Implement decorator to execute the SQL queries and reduce code duplication.
- Implement SQL query builder (e.g. squel.js) to erradicate the need for embedding SQL directly into the code (which is error-prone).
- Change enrollments route not to use route chaining in order to decide which SQL query is appropriate to respond the user's request.
- Implement decorator for API responses and also reduce code duplication.
- Split up tests into and add more test cases.
Signed-off-by: João Victor Risso <jvtr12@c3sl.ufpr.br>

.babelrc

+{ 'presets': ['es2015'] }

.eslintrc.json

+{
+    "extends": "airbnb",
+    "plugins": [
+        "react",
+        "jsx-a11y",
+        "import"
+    ],
+    "rules": {
+        "indent": [ "error", 4 ],
+        "no-unused-vars": [ "error", { "args": "none" }],
+		"no-param-reassign": [ "off" ]
+    }
+}

.gitignore

@@ -10,7 +10,6 @@ lib-cov
 *.gz
 
 pids
-logs
 results
 
 npm-debug.log

.gitlab-ci.yml

@@ -7,6 +7,6 @@ before_script:
 run_tests:
   stage: test
   script:
-    - npm test
+    - gulp && cd build/ && mocha
   tags:
     - node

build/config.json

+{
+    "port": 3000,
+    "monetdb": {
+        "host": "localhost",
+        "port": 50000,
+        "dbname": "simcaq_dev",
+        "user": "monetdb",
+        "password":"monetdb",
+        "nrConnections": 16
+    },
+    "default": {
+        "api": {
+            "version" : "v1"
+        }
+    }
+}

build/libs/app.js

+'use strict';
+
+var express = require('express');
+var cookieParser = require('cookie-parser');
+var bodyParser = require('body-parser');
+var methodOverride = require('method-override');
+var cors = require('cors');
+
+var log = require('./log')(module);
+
+var api = require('./routes/api');
+var states = require('./routes/states');
+var regions = require('./routes/regions');
+var cities = require('./routes/cities');
+
+var app = express();
+
+app.use(bodyParser.json());
+app.use(bodyParser.urlencoded({ extended: false }));
+app.use(cookieParser());
+app.use(cors());
+app.use(methodOverride());
+
+app.use('/v1/', api);
+app.use('/v1/states', states);
+app.use('/v1/regions', regions);
+app.use('/v1/cities', cities);
+
+// catch 404 and forward to error handler
+app.use(function (req, res, next) {
+    res.status(404);
+    log.debug('%s %d %s', req.method, res.statusCode, req.url);
+    res.json({ error: 'Not found' }).end();
+});
+
+// error handlers
+app.use(function (err, req, res, next) {
+    res.status(err.status || 500);
+    log.error('%s %d %s', req.method, res.statusCode, err.message);
+    res.json({ error: err.message }).end();
+});
+
+module.exports = app;
\ No newline at end of file

build/libs/config.js

+'use strict';
+
+var nconf = require('nconf');
+
+nconf.argv().env().file({ file: process.cwd() + '/config.json' });
+
+module.exports = nconf;
\ No newline at end of file

libs/db/monet.js → build/libs/db/monet.js

-var mdb = require('monetdb')()
+'use strict';
 
-var libs = process.cwd() + '/libs/'
+var MonetDBPool = require('monetdb-pool');
 
-var log = require(libs + 'log')(module)
-var config = require(libs + 'config')
+var libs = process.cwd() + '/libs';
+
+var config = require(libs + '/config');
+
+var poolOptions = {
+    nrConnections: config.get('monetdb:nrConnections')
+};
 
 var options = {
     host: config.get('monetdb:host'),
@@ -11,9 +16,9 @@ var options = {
     dbname: config.get('monetdb:dbname'),
     user: config.get('monetdb:user'),
     password: config.get('monetdb:password')
-}
+};
 
-var conn = new mdb(options)
-conn.connect()
+var conn = new MonetDBPool(poolOptions, options);
+conn.connect();
 
-module.exports = conn
+module.exports = conn;
\ No newline at end of file

build/libs/db/query_decorator.js

+"use strict";
+
+var libs = process.cwd() + "/libs";
+var log = require(libs + "/log")(module);
+var conn = require(libs + "/db/monet");
+
+/**
+ * Basic decorator to wrap SQL query strings
+ */
+exports.execQuery = function (sqlQuery, sqlQueryParams) {
+    log.debug("Executing SQL query '" + sqlQuery + "' with params '" + sqlQueryParams + "'");
+    conn.prepare(sqlQuery, true).then(function (dbQuery) {
+        dbQuery.exec(sqlQueryParams).then(function (dbResult) {
+            log.debug(dbResult.data);
+            log.debug("Query result: " + dbResult.data);
+            return dbResult;
+        }, function (error) {
+            log.error("SQL query execution error: " + error.message);
+            return error;
+        });
+    });
+};
\ No newline at end of file

build/libs/enrollment/all.js

+"use strict";
\ No newline at end of file

build/libs/enrollment/city.js

+"use strict";
\ No newline at end of file

build/libs/enrollment/common.js

+'use strict';
+
+var libs = process.cwd() + '/libs';
+
+var log = require(libs + '/log')(module);
+
+var sqlDecorator = require(libs + '/query_decorator');
+
+var yearRange = function yearRange() {
+    var yearSql = 'SELECT MIN(t.ano_censo) AS start_year, MAX(t.ano_censo)' + 'AS end_year FROM turmas AS t';
+    log.debug('Generated SQL query for enrollments\' year range');
+    return sqlDecorator.execQuery(yearSql, []);
+};
+
+module.exports = yearRange;
\ No newline at end of file

build/libs/enrollment/country.js

+"use strict";
\ No newline at end of file

build/libs/enrollment/region.js

+"use strict";
\ No newline at end of file

build/libs/enrollment/state.js

+"use strict";
\ No newline at end of file

build/libs/log.js

+'use strict';
+
+var winston = require('winston');
+
+winston.emitErrs = true;
+
+function getFilePath(module) {
+    // using filename in log statements
+    return module.filename.split('/').slice(-2).join('/');
+}
+
+function logger(module) {
+    return new winston.Logger({
+        transports: [new winston.transports.File({
+            level: 'info',
+            filename: process.cwd() + '/logs/all.log',
+            handleException: true,
+            json: false,
+            maxSize: 5242880, // 5MB
+            maxFiles: 2,
+            colorize: false
+        }), new winston.transports.Console({
+            level: 'debug',
+            label: getFilePath(module),
+            handleException: true,
+            json: true,
+            colorize: true
+        })],
+        exitOnError: false
+    });
+}
+
+module.exports = logger;
\ No newline at end of file

build/libs/query_decorator.js

+"use strict";
+
+var libs = process.cwd() + "/libs";
+var log = require(libs + "/log")(module);
+var conn = require(libs + "/db/monet");
+
+/**
+ * Basic decorator to wrap SQL query strings
+ */
+exports.execQuery = function (sqlQuery, sqlQueryParams) {
+    log.debug("Executing SQL query '" + sqlQuery + "' with params '" + sqlQueryParams + "'");
+    conn.prepare(sqlQuery, true).then(function (dbQuery) {
+        dbQuery.exec(sqlQueryParams).then(function (dbResult) {
+            log.debug(dbResult.data);
+            log.debug("Query result: " + dbResult.data);
+            return dbResult;
+        }, function (error) {
+            log.error("SQL query execution error: " + error.message);
+            return error;
+        });
+    });
+};
\ No newline at end of file

build/libs/routes/cities.js

+'use strict';
+
+var express = require('express');
+
+var xml = require('js2xmlparser');
+
+var cityApp = express();
+
+var libs = process.cwd() + '/libs';
+
+var log = require(libs + '/log')(module);
+
+var conn = require(libs + '/db/monet');
+
+function response(req, res) {
+    if (req.query.format === 'csv') {
+        res.csv(req.result.data);
+    } else if (req.query.format === 'xml') {
+        res.send(xml('result', JSON.stringify({ city: req.result.data })));
+    } else {
+        res.json({ result: req.result.data });
+    }
+}
+
+cityApp.get('/', function (req, res) {
+    conn.query('SELECT * FROM municipios', true).then(function (dbResult) {
+        log.debug(dbResult);
+        req.result = dbResult;
+        response(req, res);
+    }, function (dbError) {
+        log.error('SQL query execution error: ' + dbError.message);
+        // FIXME: change response to HTTP 501 status
+        res.json({ error: 'An internal error has occurred' }).end();
+    });
+});
+
+cityApp.get('/:id', function (req, res) {
+    var citySql = 'SELECT * FROM municipios WHERE pk_municipio_id = ?';
+    var cityId = parseInt(req.params.id, 10);
+    conn.prepare(citySql, true).then(function (dbQuery) {
+        dbQuery.exec([cityId]).then(function (dbResult) {
+            log.debug(dbResult);
+            req.result = dbResult;
+            response(req, res);
+        }, function (dbError) {
+            log.error('SQL query execution error: ' + dbError.message);
+            // FIXME: change response to HTTP 501 status
+            res.json({ error: 'An internal error has occurred' }).end();
+        });
+    });
+});
+
+cityApp.get('/ibge/:id', function (req, res) {
+    var citySql = 'SELECT * FROM municipios WHERE codigo_ibge = ?';
+    var cityId = parseInt(req.params.id, 10);
+    conn.prepare(citySql, true).then(function (dbQuery) {
+        dbQuery.exec([cityId]).then(function (dbResult) {
+            log.debug(dbResult);
+            req.result = dbResult;
+            response(req, res);
+        }, function (dbError) {
+            log.error('SQL query execution error: ' + dbError.message);
+            // FIXME: change response to HTTP 501 status
+            res.json({ error: 'An internal error has occurred' }).end();
+        });
+    });
+});
+
+cityApp.get('/state/:id', function (req, res) {
+    var citySql = 'SELECT * FROM municipios WHERE fk_estado_id = ?';
+    var stateId = parseInt(req.params.id, 10);
+    conn.prepare(citySql, true).then(function (dbQuery) {
+        dbQuery.exec([stateId]).then(function (dbResult) {
+            log.debug(dbResult);
+            req.result = dbResult;
+            response(req, res);
+        }, function (dbError) {
+            log.error('SQL query execution error: ' + dbError.message);
+            // FIXME: change response to HTTP 501 status
+            res.json({ error: 'An internal error has occurred' }).end();
+        });
+    });
+});
+
+module.exports = cityApp;
\ No newline at end of file

build/libs/routes/regions.js

+'use strict';
+
+var express = require('express');
+
+var xml = require('js2xmlparser');
+
+var regionApp = express();
+
+var libs = process.cwd() + '/libs';
+
+var log = require(libs + '/log')(module);
+
+var conn = require(libs + '/db/monet');
+
+function response(req, res) {
+    if (req.query.format === 'csv') {
+        res.csv(req.result.data);
+    } else if (req.query.format === 'xml') {
+        res.send(xml('result', JSON.stringify({ state: req.result.data })));
+    } else {
+        res.json({ result: req.result.data });
+    }
+}
+
+regionApp.get('/', function (req, res) {
+    var regionSql = 'SELECT * FROM regioes';
+    conn.query(regionSql, true).then(function (dbResult) {
+        log.debug(dbResult);
+        req.result = dbResult;
+        response(req, res);
+    }, function (dbError) {
+        log.error('SQL query execution error: ' + dbError.message);
+        // FIXME: change response to HTTP 501 status
+        res.json({ error: 'An internal error has occurred' }).end();
+    });
+});
+
+regionApp.get('/:id', function (req, res) {
+    var regionSql = 'SELECT * FROM regioes WHERE pk_regiao_id = ?';
+    var regionId = parseInt(req.params.id, 10);
+    conn.prepare(regionSql, true).then(function (dbQuery) {
+        dbQuery.exec([regionId]).then(function (dbResult) {
+            log.debug(dbResult);
+            req.result = dbResult;
+            response(req, res);
+        }, function (dbError) {
+            log.error('SQL query execution error: ' + dbError.message);
+            // FIXME: change response to HTTP 501 status
+            res.json({ error: 'An internal error has occurred' }).end();
+        });
+    });
+});
+
+module.exports = regionApp;
\ No newline at end of file

build/libs/routes/states.js

+'use strict';
+
+var express = require('express');
+
+var xml = require('js2xmlparser');
+
+var stateApp = express();
+
+var libs = process.cwd() + '/libs';
+
+var log = require(libs + '/log')(module);
+
+var conn = require(libs + '/db/monet');
+
+function response(req, res) {
+    if (req.query.format === 'csv') {
+        res.csv(req.result.data);
+    } else if (req.query.format === 'xml') {
+        res.send(xml('result', JSON.stringify({ state: req.result.data })));
+    } else {
+        res.json({ result: req.result.data });
+    }
+}
+
+stateApp.get('/', function (req, res, next) {
+    var stateSql = 'SELECT * FROM estados';
+    conn.query(stateSql, true).then(function (dbResult) {
+        log.debug(dbResult);
+        req.result = dbResult;
+        response(req, res);
+    }, function (dbError) {
+        log.error('SQL query execution error: ' + dbError.message);
+        // FIXME: change response to HTTP 501 status
+        res.json({ error: 'An internal error has occurred' }).end();
+    });
+});
+
+stateApp.get('/:id', function (req, res, next) {
+    var stateSql = 'SELECT * FROM estados WHERE pk_estado_id = ?';
+    var stateId = parseInt(req.params.id, 10);
+    conn.prepare(stateSql, true).then(function (dbQuery) {
+        dbQuery.exec([stateId]).then(function (dbResult) {
+            log.debug(dbResult);
+            req.result = dbResult;
+            response(req, res);
+        }, function (dbError) {
+            log.error('SQL query execution error: ' + dbError.message);
+            // FIXME: change response to HTTP 501 status
+            res.json({ error: 'An internal error has occurred' }).end();
+        });
+    });
+});
+
+stateApp.get('/region/:id', function (req, res, next) {
+    var stateSql = 'SELECT * FROM estados WHERE fk_regiao_id = ?';
+    var regionId = parseInt(req.params.id, 10);
+    conn.prepare(stateSql, true).then(function (dbQuery) {
+        dbQuery.exec([regionId]).then(function (dbResult) {
+            log.debug(dbResult);
+            req.result = dbResult;
+            response(req, res);
+        }, function (dbError) {
+            log.error('SQL query execution error: ' + dbError.message);
+            // FIXME: change response to HTTP 501 status
+            res.json({ error: 'An internal error has occurred' }).end();
+        });
+    });
+});
+
+module.exports = stateApp;
\ No newline at end of file

build/logs/.gitignore

+*.log

build/server.js

+'use strict';
+
+var debug = require('debug')('node-express-base');
+
+var libs = process.cwd() + '/libs';
+
+var config = require(libs + '/config');
+
+var log = require(libs + '/log')(module);
+
+var app = require(libs + '/app');
+
+app.set('port', config.get('port') || 3000);
+
+var server = app.listen(app.get('port'), function () {
+    debug('Express server listening on port ' + server.address().port);
+    log.info('Express server listening on port ' + config.get('port'));
+});
\ No newline at end of file

build/test/test.js

+'use strict';
+
+var chai = require('chai');
+var chaiHttp = require('chai-http');
+var assert = chai.assert;
+var expect = chai.expect;
+var should = chai.should(); // actually call the function
+var server = require('../libs/app');
+
+chai.use(chaiHttp);
+
+describe('request enrollments', function () {
+    it('should list enrollments', function (done) {
+        chai.request(server).get('/v1/enrollments').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result[0].should.have.property('name');
+            res.body.result[0].should.have.property('total');
+            done();
+        });
+    });
+});
+
+describe('request regions', function () {
+    it('should list all regions', function (done) {
+        chai.request(server).get('/v1/regions').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result[0].should.have.property('pk_regiao_id');
+            res.body.result[0].should.have.property('nome');
+            done();
+        });
+    });
+
+    it('should list region by id', function (done) {
+        chai.request(server).get('/v1/regions/1').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result.should.have.length(1);
+            res.body.result[0].should.have.property('pk_regiao_id');
+            res.body.result[0].should.have.property('nome');
+            done();
+        });
+    });
+});
+
+describe('request states', function () {
+
+    it('should list all states', function (done) {
+        chai.request(server).get('/v1/states').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result[0].should.have.property('pk_estado_id');
+            res.body.result[0].should.have.property('fk_regiao_id');
+            res.body.result[0].should.have.property('nome');
+            done();
+        });
+    });
+
+    it('should list a state by id', function (done) {
+        chai.request(server).get('/v1/states/11').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result.should.have.length(1);
+            res.body.result[0].should.have.property('pk_estado_id');
+            res.body.result[0].should.have.property('fk_regiao_id');
+            res.body.result[0].should.have.property('nome');
+            done();
+        });
+    });
+
+    it('should list states by region id', function (done) {
+        chai.request(server).get('/v1/states/region/1').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result[0].should.have.property('pk_estado_id');
+            res.body.result[0].should.have.property('fk_regiao_id');
+            res.body.result[0].should.have.property('nome');
+            done();
+        });
+    });
+});
+
+describe('request cities', function () {
+
+    it('should list all cities', function (done) {
+        chai.request(server).get('/v1/cities').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;
+            res.body.should.have.property('result');
+            res.body.result.should.be.a('array');
+            res.body.result[0].should.have.property('pk_municipio_id');
+            res.body.result[0].should.have.property('fk_estado_id');
+            res.body.result[0].should.have.property('nome');
+            res.body.result[0].should.have.property('codigo_ibge');
+            done();
+        });
+    });
+
+    it('should list a city by id', function (done) {
+        chai.request(server).get('/v1/cities/1').end(function (err, res) {
+            res.should.have.status(200);
+            res.should.be.json;