maybe someone have example for creating small API on node.js
Example, i have function this function will return string
I need call this string from postman or inside any another project with http.
What better for create this API?
Maybe someone know good guide? I worked before with node.js only like web-server
It is best practice that building API's in nodejs with express.Here is a code in which function returns a string. You need to export it. And require the file that contains exported value in your project file with the file path. Here is my function code where I am returning a string value. func.js
var string;
function myfunc(param,callback){
var str="hello";
callback(null,str);
}
myfunc('aaa',function(err,result){
if(err){
console.log(err);
}
else{
exports.string=result;
}
});
Here is my routes file and here I am calling the string from func.js and I named this file as str.js
var http = require('http');
var express = require('express');
var main = require('./func.js');//path of file
var org = main.string;
var app = express();
app.get('/str',function(req,res){
console.log(org);
res.send(org);
});
app.listen(3000,function(){
console.log("Server listening on 3000");
});
Run the code as node str.js and in postman run the url as http://localhost:3000/str and you can see the returned string in both response and in terminal.
Hope this helps...
This tutorial shows you how to build an API in Node.js with Express.
EDIT: You can skip the database part if you don't need it.
Related
I am try to load country names and want to save them in static variable. So that I do not hit in my database again and again.
I am using express Js.
Please suggest me How can i load country name in optimize ways
In node.js, modules are cached after the first time they are loaded. Every call to import/require will retrieve exactly the same object.
A good way to achieve this is:
app.js
var app = require('express')(),
server = require('http').createServer(app);
var lookup=require('./lookup.js');
server.listen(80, function() {
//Just one init call
lookup.callToDb(function(){
console.log('ready to go!');
});
});
lookup.js
callToDb(function (country){
module.exports=country;
});
and wherever you require:
model.js
var countryLookup= require('./lookup.js');
I am using Koa for web development in NodeJS, I have a server file, which does nothing but to start the server and initialise few middlewares. Following is the sample code
server.js
const Koa = require('koa');
var Router = require('koa-router');
var bodyParser = require('koa-bodyparser');
var app = new Koa();
var router = new Router();
app.use(bodyParser());
router.post('/abc', AbcController.abcAction);
router.post('/pqr', PqrController.pqrAction);
app.use(router.routes());
app.listen(3000);
When we run npm start the server will start on 3000 port and now I want to write unit test case for this file using mocha, chai and sinon.
One way is to create a test file lets say server_test.js and do something like the following(just an example):
var server = require(./server);
server.close();
For this we need to add the following lines to server.js
var server = app.listen(3000);
module.exports = server;
Is this a good practice to do? I think we should not expose server in this fashion?
As we don't have self created function here in this file, is testing really required?
Should we also exclude such files from sonarqube coverage?
Any other better suggestion is always welcome. Need your help guys. Thank you.
You can use chai-http for testing the endpoint
this is what I use for my project
const chai = require('chai');
const chaiHttp = require('chai-http');
const expect = chai.expect;
const app = require('../app');
describe('/GET roles', function () {
it('should return bla bla bla',
function (done) {
chai.request(app)
.get('/roles')
.end(function (err, res) {
expect(res.status).eql(200)
expect(res.body).to.have.property('message').eql('Get role list success');
expect(res.body).to.have.property('roles');
expect(err).to.be.null;
done();
});
}
);
});
There are primarily 2 ways through which you can actually handle rest cases.
One is to put your test cases along with your source code file. ( in your case it would be server.spec.js ). I personally prefer this way as it encourages code modularity and make your modules totally independent.
Another way is to create another directory, let say test, where you can put your entire test cases according to same directory structure as followed by the main application. This is really useful for applications where test cases are only considered while they are in development phase and then at time of production you can simply ignore sending these files.
Also, I usually prefer following the concepts of functional programming as it really helps to test each block of code independently.
Hope this helps
I have the following test application based on a template provided by openshift.
server.js:
var express = require('express');
exports.NodeTestApp = function () {
self.cache_get = function (key) {
return 'Would be a value here';
};
}
server_test.js:
var server = require('../server');
describe('Server', function(){
describe('Startup',function(){
it('sets up routes during startup',function(){
var app = server.NodeTestApp();
app.cache_get('/');
expect(app.routes.size).to.equals(5);
})
})
})
When I run this test I get an error message that cache_get is not defined.
TypeError: Cannot read property 'cache_get' of undefined
at Context.<anonymous> (test/server_test.js:7:16)
I would have thought that everything that is specified in the NodeTestApp function is available via variable app. IntelliJ even shows me the function as a valid call. Any idea why I get this error ?
Thanks in advance.
Oliver
I figured out the problem with above code. To instantiate the app variable the new keyword has to be used. I didn't think that this is required as I would have thought its purely a function call and not a constructor call, which requires the new keyword. Below is the working code for your reference.
var app = new server.NodeTestApp();
I am calling a function from an external JS file in my routes file. So, I am trying to export a function from my externalFile.js file. However, when I run the node server, it throws Uncaught ReferenceError: exports is not defined . externalFile.js is in public/javascripts/ and the route files is in routes/.
External file (externalFile.js):
exports.capsolvingComplete = function (stdout){
//Received, display text and hide the spinner, put check in place.
$('#capsolv-complete').css("display", "block")
$('#capsolv-output').text(stdout);
}
Route file:
var express = require('express');
var router = express.Router();
var script = require('../public/javascripts/externalFile.js')
/* GET home page. */
router.get('/', function(req, res) {
res.render('index', { title: 'CapSolv' });
});
router.post('/file-upload', function(req, res){
script.capsolvingComplete("HI");
res.end("success");
})
module.exports = router;
Thank you for your help! Bit of a node noob here.
Looking at your example, mscdex is right. Anything you require in Node is designed to run on the server, and doesn't have access to the browser's DOM.
I would recommend building a REST API that accepts the file upload, stores it, and returns a JSON object containing metadata: i.e. where the file was stored, size, etc., and let your client deal with that.
I'd like to override the View class in the Express framework, used in Node.js. I want to augment the lookup method, but I can't see a way to do this without altering the Express and App modules. I'd favour deriving from the Express framework, but I can't figure out a neat way to do this.
Any ideas?
Thanks
It seems to me you should be able to:
var View = require('express/lib/view');
// Keep reference to original lookup method
var _lookup = View.prototype.lookup;
// Override lookup method
View.prototype.lookup = function (path) {
// Your implementation here
};
Update:
Run this as a demonstration:
var View = require('express/lib/view');
var _lookup = View.prototype.lookup;
var express = require('express');
View.prototype.lookup = function (path) {
console.log('LOOKUP!!! ' + path);
return _lookup.call(this, path);
};
var app = express();
app.get('/', function (req, res) {
res.render('foo.jade');
});
app.listen(3000);
Run
node app & sleep 1 && curl localhost:3000
I hope this will demonstrate the viability of this way of overriding a method.
It depends on which version of Express you are using.
You can easily augment the view lookup code only if your app is using Express prior to version 3
Since Express 3.0 that's not doable anymore.
You can check one of my old related answers for sample code:
Multiple View paths on Node.js + Express