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Node Js : Unable to find error in below file filter code

I have written small code to get files filtered by extension. And my point of view logic is fine but I am unable to point out why I am not getting expected output.
Please have a look.
CODE
var fs = require('fs')
var path = require('path')
path_name = process.argv[2]
ext_name = "."+process.argv[3]
var filter_function = function ( path_name,exthide_name,callback) {
fs.readdir(dirpath,function(err,list) {
if(err) return console.error(err)
for ( var i in list) {
if(path.extname(list[i]) == ext_name)
console.log(list[i])
}
})
}
module.exports=filter_function
Output :
linuxmen#linuxmen-fresh:~/test/test1$ node ownModuleNode.js /home/linuxmen/test/test1/ js
linuxmen#linuxmen-fresh:~/test/test1$
But I have so many files with js extension in that directory.
Proof:
linuxmen#linuxmen-fresh:~/test/test1$ ls *js
check_mod1.js ex1.js ex2.js ex3.js ex4.js ex5.js ex6.js ex7.js ex8.js filter.js filter_use.js modse.js ownModuleNode.js se.js use_mod1.js using_module.js
Could please help , what I am missing.
Update - 1 : I am using above code a module file and calling it here.
File using above code
var mymodule = require('./ownModuleNode')
mymodule.filter_function(process.argv[2],process.argv[3])
Update 2 :
var fs = require('fs')
var path = require('path')
path_name = process.argv[2]
ext_name = "."+process.argv[3]
console.log("path_name :",path_name,"extname:",ext_name)
var filter_function = function ( path_name,ext_name,callback) {
fs.readdir(path_name,function(err,list) {
if (err) console.error(err)
console.log(list)
for ( var i in list) {
if(path.extname(list[i]) == ext_name)
console.log(list[i])
}
})
}
module.exports=filter_function
Output:
linuxmen#linuxmen-fresh:~/test/test1$ node ownModuleNode.js /home/linuxmen/test/test1/ js
pathanme : /home/linuxmen/test/test1/ extname: .js
Thank you.

It looks like you are exporting the function directly. When you require() it, you just getting the function. You'll need to use your module in your application. Put this in 'app.js' in the same dir as ownModuleNode.js:
var filterFunction = require('./ownModuleNode');
filterFunction(process.argv[2], process.argv[3]);
Then call it with:
node app ~/Documents/dev/project .js
Outputs:
app.js
ownModuleNode.js
Note that when you pass the extension, you need the preceding dot because path.extname() returns the dot.

How to get gulp to error on missing file?

I've got gulpfile.js set up like this:
var scripts = [
'bower_components/timezone-js/src/date.js',
'bower_components/jquery/jquery.min.js',
'bower_components/jquery-migrate/jquery-migrate.js',
'bower_components/jquery-ui/ui/minified/jquery-ui.min.js',
'bower_components/jqueryui-touch-punch/jquery.ui.touch-punch.min.js',
...
];
gulp.task('scripts', function () {
return gulp.src(scripts, {base: '.'})
.pipe(plumber(plumberOptions))
.pipe(sourcemaps.init({
loadMaps: false,
debug: debug,
}))
...
i.e., all my script files are exact matches. No globbing.
Every now and then I mess up a file path or the author changes the directory structure. I want to be notified when this happens instead of the script silently being excluded and causing run-time errors.
Is there some way for me to make gulp.src report these kinds of errors?

Use gulp-expect-file as per this answer.
var coffee = require('gulp-coffee');
var expect = require('gulp-expect-file');
gulp.task('mytask', function() {
var files = ['idontexist.html'];
return gulp.src(files)
.pipe(expect(files))
.pipe(coffee());
});
(Thanks rve)

gulp.src is actually just an alias to vinyl-fs.src which looks like this:
function src(glob, opt) {
opt = opt || {};
var pass = through.obj();
if (!isValidGlob(glob)) {
throw new Error('Invalid glob argument: ' + glob);
}
// return dead stream if empty array
if (Array.isArray(glob) && glob.length === 0) {
process.nextTick(pass.end.bind(pass));
return pass;
}
var options = defaults(opt, {
read: true,
buffer: true
});
var globStream = gs.create(glob, options);
// when people write to use just pass it through
var outputStream = globStream
.pipe(through.obj(createFile))
.pipe(getStats(options));
if (options.read !== false) {
outputStream = outputStream
.pipe(getContents(options));
}
return outputStream.pipe(pass);
}
It in turn uses glob-stream which uses glob. You can probably bypass most of that and use through2 directly to create a pipe from the array files. I haven't figured out how to do this yet.

node.js display virtual hosts and current git branch async issue

Ok, i am just starting to learn node.js and i am having a little difficulty getting a good grasp on the async nature of it and when/how to use callbacks to get data passed along like i need it.
The concept of what i am trying to build is this. I have a small node.js app that uses the FS package - defined as var fs = require("fs"). The app is responding to localhost:4000 right now. When i hit that url, the app will use fs.readdir() to get all of the virtual host files in the directory that i pass to readdir().
Next, the app loops through those files and parses each one line by line and word by word (quick and dirty for now). I am using fs.readFile() to read the file and then literally doing lines = data.toString().split("\n") and then var words = lines[l].split(" ") to get to the data in the file i need. Each virtual host file looks something like this:
<VirtualHost *:80>
ServerName some-site.local
DocumentRoot "/path/to/the/docroot"
<Directory "/path/to/the/docroot">
Options Indexes FollowSymLinks Includes ExecCGI
AllowOverride All
Require all granted
</Directory>
ErrorLog "logs/some-site.local-error_log"
</VirtualHost>
Here is my main.js file (routes file):
var express = require("express"),
router = express.Router(),
async = require("async"),
directoryReader = require(__dirname + "/../lib/directoryReader");
fileReader = require(__dirname + "/../lib/fileReader");
router.get("/", function(req, res) {
var response = [];
directoryReader.read(function(files) {
async.each(files, function(file, callback) {
fileReader.read(file, function(data) {
if (data.length > 0) {
response.push(data);
}
callback();
});
}, function(err){
if (err) throw err;
res.json(response);
});
});
});
module.exports = router;
My directoryReader.js file:
var fs = require("fs"),
fileReader = require(__dirname + "/../lib/fileReader");
var directoryReader = {
read: function(callback) {
var self = this;
fs.readdir("/etc/apache2/sites-available", function (err, files) {
if (err) throw err;
var output = [];
for(f in files) {
output.push(files[f]);
}
callback(output);
});
}
};
module.exports = directoryReader;
And my fileReader.js file:
var fs = require("fs");
var fileReader = {
read: function(file, callback) {
fs.readFile("/etc/apache2/sites-available/" + file, { encoding: "utf8" }, function (err, data) {
if (err) throw err;
var vHostStats = ["servername", "documentroot", "errorlog"],
lines = data.toString().split("\n"),
output = [];
for(l in lines) {
var words = lines[l].split(" ");
for(w in words) {
if (words[w].toLowerCase() == "<virtualhost") {
var site = {
"servername" : "",
"documentroot" : "",
"errorlog" : "",
"gitbranch" : ""
}
w++;
}
if (vHostStats.indexOf(words[w].toLowerCase()) !== -1) {
var key = words[w].toLowerCase();
w++;
site[key] = words[w];
}
if (words[w].toLowerCase() == "</virtualhost>" && site.documentroot != "") {
w++;
output.push(site);
var cmd = "cd " + site["documentroot"] + " && git rev-parse --abbrev-ref HEAD";
var branch = ...; // get Git branch based on the above command
site["gitbranch"] = branch;
}
}
}
callback(output);
});
}
};
module.exports = fileReader;
All of this code will spit out json. This all works fine, expect for one part. The line in the fileReader.js file:
var branch = ...; // get Git branch based on the above command
I am trying to get this code to run a shell command and get the Git branch based on the document root directory. I then want to take the branch returned and add the value to the gitbranch proptery of the current site object during the loop. Hope this makes sense. I know there are probably questions on SO that cover something similar to this and i have looked at many of them. I fear i am just not educated enough in node.js yet to apply the answers to those SO questions to my particular use case.
Please let me know if there's anything i can add that can help anyoe answer this question. I should note that this app is for personal uses only, so the solution really just has to work, not be super elegant.
UPDATE: (5/1/2015)
Probably not the best solution but i got what i wanted by using the new execSync added to v0.12.x
if (words[w].toLowerCase() == "</virtualhost>" && site.documentroot != "") {
var cmd = "cd " + site["documentroot"] + " && git rev-parse --abbrev-ref HEAD";
var branch = sh(cmd, { encoding: "utf8" });
site["gitbranch"] = branch.toString().trim();
w++;
output.push(site);
}

Can I mock console in NodeJs?

In my JS test, I need to check if the console.info is called. That's why I want to mock console. However, it seems that the console variable cannot be assigned with a different object. Did I make any mistake?
Here is the code I used:
var oldConsole = console;
var infoContent;
console = {
info: function(content) {
infoContent = content;
}
};
game.process('a command');
infoContent.should.equal('a command is processed');
console = oldConsole;

You can use rewire to replace the whole of console to silence it, or to inject a mock. I use deride but sinon would also work.
var rewire = require('rewire');
var deride = require('deride');
var Game = rewire('../lib/game');
describe('game testing', function() {
var stubConsole, game;
beforeEach(function() {
stubConsole = deride.stub(['info']);
stubConsole.setup.info.toReturn();
Game.__set__({
console: stubConsole
});
game = new Game();
});
it('logs info messages', function() {
game.process('a command');
stubConsole.expect.info.called.withArgs(['a command is processed']);
});
});

I find the solution. I can change the method info of console.
console.info = function(content) {
infoContent = content;
};
The question is now why console object itself cannot be reassigned?

you can use sinon npm to count the call to a function :
it("calls the original function only once", function () {
var callback = sinon.spy();
var proxy = once(callback);
proxy();
proxy();
assert(callback.calledOnce);
// ...or:
// assert.equals(callback.callCount, 1);
});
You can find the docs here : sinonjs.org

I thought I had the same problem and my solution was using this std-mocks module:
https://github.com/neoziro/std-mocks
This has the advantage of not taking over the global "console" but allows you to see what gets logged to the stdout / stderr. This solves the problem in a different way than the question was explicitly looking for; however I believe it is a good answer for the problem the question implies and may be useful for others.
const stdMocks = require('std-mocks');
stdMocks.use(); console.log('test'); stdMocks.restore();
// => undefined [nothing gets output, stdout intercepted]
const logged = stdMocks.flush();
console.log(logged)
// => { stdout: [ 'test\n' ], stderr: [] }

How can I use these Node modules to accept HTML through a file or URL and then output JSON as validation of existing HTML elements?

Essentially what I need to do is to take a local grader.js file and then use it at the command line to input HTML, which will then output JSON data to the console to validate the existence of several HTML elements. The usage looks something like this:
./grader.js --checks checks.json --file index.html
./grader.js --checks checks.json --url http://google.com
The Node modules being used are Commander (for working at the command line), Cheerio (for HTML), and Restler (for getting HTML from URL).
The checks.json file is straightforward in that it's simply asking to check for the existence of a few simple HTML elements to find out whether or not they exist on the page:
["h1",
".navigation",
".logo",
".blank",
".about",
".heading",
".subheading",
".pitch",
".video",
".thermometer",
".order",
".social",
".section1",
".section2",
".faq",
".footer"]
The grader.js file is where things get a little more complicated. The following code actually works insofar as it takes the command line arguments and does indicate a true or false value as to whether the HTML elements exist. But it doesn't work properly after adding the URL check at the bottom. There is something wrong with my checkURL function and the way that I implement it using the Commander code at the bottom. Even though the true and false values are correct dependent upon the HTML file/URL I use, I end up spitting out both checks to the console even if I only want to check either the file or the URL, not both. I'm fairly new to this so I'm surprised that it works at all. It may have something to do with the default values, but when I try to make those changes the checkURL function seems to break down. Thanks in advance for your help I really do appreciate it.
#!/usr/bin/env node
var fs = require('fs');
var program = require('commander');
var cheerio = require('cheerio');
var rest = require('restler');
var HTMLFILE_DEFAULT = "index.html";
var CHECKSFILE_DEFAULT = "checks.json";
var URL_DEFAULT = "http://cryptic-spire-7925.herokuapp.com/index.html";
var assertFileExists = function(infile) {
var instr = infile.toString();
if(!fs.existsSync(instr)) {
console.log("%s does not exist. Exiting.", instr);
process.exit(1); // http://nodejs.org/api/process.html#process_process_exit_code
}
return instr;
};
var cheerioHtmlFile = function(htmlfile) {
return cheerio.load(fs.readFileSync(htmlfile));
};
var loadChecks = function(checksfile) {
return JSON.parse(fs.readFileSync(checksfile));
};
var checkHtmlFile = function(htmlfile, checksfile) {
$ = cheerioHtmlFile(htmlfile);
var checks = loadChecks(checksfile).sort();
var out = {};
for(var ii in checks) {
var present = $(checks[ii]).length > 0;
out[checks[ii]] = present;
}
return out;
};
var checkUrl = function(url, checksfile) {
rest.get(url).on('complete', function(data) {
$ = cheerio.load(data);
var checks = loadChecks(checksfile).sort();
var out = {};
for(var ii in checks) {
var present = $(checks[ii]).length > 0;
out[checks[ii]] = present;
}
console.log(out);
});
}
var clone = function(fn) {
// Workaround for commander.js issue.
// http://stackoverflow.com/a/6772648
return fn.bind({});
};
if(require.main == module) {
program
.option('-f, --file <html_file>', 'Path to index.html', clone(assertFileExists), HTMLFILE_DEFAULT)
.option('-u, --url <url>', 'URL to index.html', URL_DEFAULT)
.option('-c, --checks <check_file>', 'Path to checks.json', clone(assertFileExists), CHECKSFILE_DEFAULT)
.parse(process.argv);
var checkJson = checkHtmlFile(program.file, program.checks);
var outJson = JSON.stringify(checkJson, null, 4);
console.log(outJson);
var checkJson2 = checkUrl(program.url, program.checks);
var outJson2 = JSON.stringify(checkJson2, null, 4);
console.log(outJson2);
}
else {
exports.checkHtmlFile = checkHtmlFile;
}

Depending on the arguments call either one of checkHtmlFile() or checkUrl()
Something like:
if (program.url)
checkUrl(program.url, program.checks);
else checkHtmlFile(program.file, program.checks);
Read this for more references: commander.js option parsing
Also, checkJson2 is undefined as checkUrl() isn't returning anything.

Those commander .option lines look wrong to me.
Delete the clone function and revise your option lines as follows:
.option('-f, --file <html_file>', 'Path to index.html', HTMLFILE_DEFAULT)
.option('-u, --url <url>', 'URL to index.html', URL_DEFAULT)
.option('-c, --checks <check_file>', 'Path to checks.json', CHECKSFILE_DEFAULT)
This should solve your commander problem.

Here is the updated checkUrl function after the helpful hints from #David and #ankitsabharwal.
var checkUrl = function(url, checksfile) {
rest.get(url).on('complete', function(data) {
$ = cheerio.load(data);
var checks = loadChecks(checksfile).sort();
var out = {};
for(var ii in checks) {
var present = $(checks[ii]).length > 0;
out[checks[ii]] = present;
}
var outJson = JSON.stringify(out, null, 4);
console.log(outJson);
});
}
And here is the updated Commander code below:
if(require.main == module) {
program
.option('-f, --file <html_file>', 'Path to index.html')
.option('-u, --url <url>', 'URL to index.html')
.option('-c, --checks <check_file>', 'Path to checks.json')
.parse(process.argv);
if (program.url) {
checkUrl(program.url, program.checks);
} else {
checkHtmlFile (program.file, program.checks);
var checkJson = checkHtmlFile(program.file, program.checks);
var outJson = JSON.stringify(checkJson, null, 4);
console.log(outJson);
}
}