In mocha testing framework is there any possibility to store the test reports in local file - node.js

Question

Im using mocha framework in my node application.If i run my test file using mocha means i'm getting error reports in terminal but i want to store the reports in local file.How can i do that.Is there any builtin method for this in mocha.
describe('Test with mocha', function(){
it ('result should be true',function(done){
var finalResult=false;
expect(finalResult).to.be(true);
done();
});
});

Answer 1

no there no built-in feature for mocha to do this, but you can do some other stuff by working with pipes which are standard in OSes.
open up a terminal, and give the command
mocha TEST.js > report.txt
the command above simply pipes all output to report.txt file.
You can also try working with child_process module from node, where you pretty much do the same thing as the command line, but in pure js.
*code is from node.js docs
var fs = require('fs'),
spawn = require('child_process').spawn,
out = fs.openSync('./out.log', 'a'),
err = fs.openSync('./out.log', 'a');
var child = spawn('prg', [], {
stdio: [ 'ignore', out, err ]
});
child.unref();

Answer 2

Ideally you can use mocha-junit-reporter and write output to XML file.
mocha tests --recursive --reporter mocha-junit-reporter --reporter-options mochaFile=./myJUnitfile.xml
If by local file you mean simple txt file then I have a sample code for you on which you can extend your own implementation. Please note that following code is only for knowledge sake. It doesn't handle many of the reporter events such as test suite start, and end etc., and exceptions that may be thrown by file operations.
For complete list of reporter events refer to https://github.com/mochajs/mocha/wiki/Third-party-reporters.
Also the following code is extended from the sample code present in above link.
// This code is extended on the orginal source present
// at https://github.com/mochajs/mocha/wiki/Third-party-reporters
// my-file-reporter.js
const mocha = require('mocha');
const fs = require('fs');
const os = require("os");
module.exports = MyFileReporter;
function MyFileReporter(runner, options) {
this._mochaFile = options.reporterOptions.mochaFile || process.env.MOCHA_FILE || 'test-results.txt';
mocha.reporters.Base.call(this, runner);
var passes = 0;
var failures = 0;
runner.on('start', function() {
if (fs.existsSync(this._mochaFile)) {
console.log('Removing existing test result file!');
fs.unlinkSync(this._mochaFile);
}
}.bind(this));
runner.on('pass', function(test){
passes++;
console.log('Pass: %s', test.fullTitle()); // Remove console.log statements if you dont need it (also below in code)
fs.appendFileSync(this._mochaFile, 'Pass: ' + test.fullTitle() + os.EOL); // Note: Exception not handled
}.bind(this));
runner.on('fail', function(test, err){
failures++;
console.log('Fail: %s -- error: %s', test.fullTitle(), err.message);
fs.appendFileSync(this._mochaFile, 'Fail: ' + test.fullTitle() + 'Error: ' + err.message + os.EOL); // Note: Exception not handled
}.bind(this));
runner.on('end', function(){
console.log('Test Summary: %d/%d', passes, passes + failures);
fs.appendFileSync(this._mochaFile, os.EOL + 'Test Summary: ' + passes + '/' + (passes + failures) + os.EOL); // Note: Exception not handled
}.bind(this));
}
Use the following command line (it assumes that my-file-reporter.js is present in the same folder where this command is executed)
mocha tests --recursive --reporter my-file-reporter --reporter-options mochaFile=./myfile.txt