Develop Reference

Find the type of the file/folder passed to the CLI in nodejs

I'm creating a CLI app and using commander to process the commands entered by the user.
program
.option('-i , --index', 'file ') // option for adding a file/folder
const options = program.opts();
if(option.index){ // do sth }
And the user can enter node index.js --index "Silver Blaze".txt or pass a folder node index.js --index "my folder"
How do I find out the type of the value passed (if it is a file or folder)?

You can use the fs module for that.
Example
let fs = require('fs')
let stats = fs.statSync(/* Path to file/folder */)
let isFile = stats.isFile()
let isDir = stats.isDirectory()
if (isFile) {
// File
} else if (isDir) {
// Directory
}
More information

How to have cli-spinner run during ShellJS command exec?

I'm currently trying to make a simple command-line node program that allows for me to easily create a boilerplate for a lot of the React/Redux applications that I make. I'm using ShellJS to execute console commands (I've tried using Node's child_process, too.) The problem is getting cli-spinner to work with executing terminal commands. Here's my code:
#! /usr/bin/env node
var shell = require('shelljs');
var userArgs = process.argv.slice(2);
var folderName = userArgs[0];
var Spinner = require('cli-spinner').Spinner;
var depSpin = new Spinner('Installing dependencies.. %s');
depSpin.setSpinnerString(10);
shell.mkdir(folderName);
shell.cd(folderName);
depSpin.start();
// I expect for the spinner to start here (before the execution of the commands.)
shell.exec('npm init -y', {silent: true});
shell.exec('npm install --save babel-core babel-loader babel-preset-es2015 babel-preset-react react-dom react-redux redux webpack', {silent: true});
shell.exec('npm install --save-dev babel-preset-env webpack-dev-server', {silent: true});
depSpin.stop();
// Since ShellJS should run synchronously,
// the spinner should stop right after the last command finishes.
shell.touch('webpack.config.js');
shell.mkdir(['build', 'frontend']);
shell.cd('frontend');
shell.mkdir(['components', 'containers', 'reducers', 'store']);
shell.touch('app.js');
But when running the program, it just hangs without displaying anything while it installs the dependencies. It's the same as when the spinner code wasn't even in there. I've also tried removing the depSpin.stop(), which just makes the program hang forever on the spinner. I have a feeling that this issue is caused by a conflict between cli-spinner and ShellJS both using the terminal.

I was able to accomplish this effect by using child_process's spawn. I had to create a child_process.spawn and run all of the commands concatenated with &&. That freed up the console output to be exclusively the cli-spinner output. I then did an event handler for when the child process exited to stop the spinner.
#! /usr/bin/env node
var shell = require('shelljs');
var userArgs = process.argv.slice(2);
var folderName = userArgs[0];
var Spinner = require('cli-spinner').Spinner;
var depSpin = new Spinner('Installing dependencies.. %s');
var spawn = require('child_process').spawn;
var commandsDep = [
'cd ' + folderName,
'npm init -y',
'npm install --save babel-core babel-loader babel-preset-es2015 babel-preset-react react-dom react-redux redux webpack',
'npm install --save-dev babel-preset-env webpack-dev-server'
];
var depChild = spawn(commandsDep.join(' && '), {
shell: true
});
depSpin.setSpinnerString(18);
shell.mkdir(folderName);
shell.cd(folderName);
depSpin.start();
depChild.on('exit', () => {
depSpin.stop();
shell.exec('clear');
console.log('Installing dependencies.. ✓');
})
shell.touch('webpack.config.js');
shell.mkdir(['build', 'frontend']);
shell.cd('frontend');
shell.mkdir(['components', 'containers', 'reducers', 'store']);
shell.touch('app.js');
shell.cd('containers');
shell.touch(['AppContainer.js', 'Root.js']);
shell.cd('../reducers');
shell.touch('index.js');
shell.cd('../store');
shell.touch('configureStore.js');

Based on Owens' answer I made a helper method myself to run long commands with a spinner inline with normal shelljs commands;
const Spinner = require('cli-spinner').Spinner;
const spinner = new Spinner('installing.. %s');
spinner.setSpinnerString('|/-\\');
var spawn = require('child_process').spawn;
const longCommand = (command, onSuccess) => {
return new Promise((resolve, reject) => {
var process = spawn(command, { shell: true });
spinner.start();
process.on('exit', () => {
spinner.stop();
onSuccess();
resolve();
})
})
}
const npmInstall = async () => {
await longCommand("npm install", () => console.log(`NPM modules installed! 👍`))
// Other stuff
shell.mkdir('new')
}
npmInstall()

Node.js - Cannot read property 'toString' of null when running package on Windows

I am using the gulp and hercule package on node.js to transclude some plain text files. On Unix, everything seems to work fine. However, some coworkers are having issues running it on Windows. They are getting the following error message only when running on Windows:
[13:02:01] TypeError: Cannot read property 'toString' of null at Object.transcludeStringSync (D:\project\node_modules\hercule\lib\hercule.js:136:36)
I have tried the above with hercule#3.0.5 as well as hercule#2.0.5, and both packages give the above error. However, given that this occurs only on Windows and across many versions of the package, I suspect this issue has something to due with the Node.js installation or path.
The code that is using the hercule package:
var fs = require('fs');
var path = require('path');
var gulp = require('gulp');
var drakov = require('drakov');
var hercule = require('hercule');
gulp.task('mock', ['i18n','build_minify_no_tests'], function() {
var mockSpecificationTemplate= fs.readFileSync('test/mock/mock-template.apib','utf8');
var transcludedMockSpecification = hercule.transcludeStringSync(mockSpecificationTemplate, {
relativePath: path.resolve('../../../')
});
fs.writeFileSync('test/mock/mock.apib', transcludedMockSpecification, 'utf-8');
// Running mock server
var drakovArgv = {
sourceFiles: 'test/mock/mock.apib',
serverPort: 9000,
staticPaths: [
'../../'
],
discover: true,
watch: true
};
drakov.run(drakovArgv);
});
node and npm version information:
$ node -v
v6.3.0
$ npm -v
3.10.3

hercule.transcludeStringSync simply runs another hercule process and sends input to it:
const result = childProcess.spawnSync('../bin/hercule', syncArgs, syncOptions);
with the script ../bin/hercule:
#!/usr/bin/env node
"use strict";
require('../lib/main.js');
...obviously doesn't work on Windows
If that task must be synchronized, you may use the following function instead:
function transcludeStringSync(input, options) {
const {dirname, join} = require('path')
const hercule = join(dirname(require.resolve('hercule')), 'main')
const args = [hercule, '--reporter', 'json-err']
for (let name in options) {
args.push(`--${name}`, `--${options[name]}`)
}
const result = require('child_process').spawnSync('node', args, {input})
const err = result.stderr.toString()
if (err) throw new Error('Could not transclude input')
return result.stdout.toString()
}

How to perform a transform on npm module using browserify

By default, browserify does not perform transforms on modules included from node_modules, i.e. with no path.
I made a quick github repo that illustrates it here. The index.js file that gets browserified looks like this:
var fs = require('fs');
var testmodule = require('testmodule');
var trg1 = document.getElementById("target1");
var trg2 = document.getElementById("target2");
trg1.innerHTML = fs.readFileSync(__dirname+"/something.txt");
trg2.innerHTML = testmodule();
testmodule looks like this:
var fs = require('fs');
exports = module.exports = function() {
return fs.readFileSync(__dirname+'/data.txt');
}
Using the brfs transform module, I want to be able to inline both calls to fs.readFileSync, but when I run browserify index.js -t brfs -o bundle.js, only the call in my main project gets inlined. Here is the bundle.js result:
;(function(e,t,n){function r(n,i){if(!t[n]){if(!e[n]){var s=typeof require=="function"&&require;if(!i&&s)return s(n,!0);throw new Error("Cannot find module '"+n+"'")}var o=t[n]={exports:{}};e[n][0](function(t){var i=e[n][1][t];return r(i?i:t)},o,o.exports)}return t[n].exports}for(var i=0;i<n.length;i++)r(n[i]);return r})({1:[function(require,module,exports){
// nothing to see here... no file methods for the browser
},{}],2:[function(require,module,exports){
var fs = require('fs');
var testmodule = require('testmodule');
var trg1 = document.getElementById("target1");
var trg2 = document.getElementById("target2");
trg1.innerHTML = "This is data from a file in the main project folder"; // TRANSFORMED
trg2.innerHTML = testmodule();
},{"fs":1,"testmodule":3}],3:[function(require,module,exports){
(function(__dirname){var fs = require('fs');
exports = module.exports = function() {
return fs.readFileSync(__dirname+'/data.txt'); // NO TRANSFORM
}
})("/node_modules/testmodule")
},{"fs":1}]},{},[2])
;

Got some help from substack (author of browserify) on this one. To specify if a module outside of a project requires transformations, you need to specify a browserify.transform array in your package.json. So for the example I gave above, the package.json file in the testmodule directory looks like this:
{
"name":"testmodule",
"version":"0.0.0",
"browserify": {
"transform": ["brfs"]
},
"main": "index.js"
}

You can also use browserify -g brfs instead of browserify -t brfs. g is a global transform (which applies to dependencies)

NPM script problems

I have a nodejs file runner.node.js.
If I run node runner.node.js it works
But if I try tu run it with npm test (it's referenced in package.json):
"test": "node ./spec/runner.node.js"
or
"test": "spec/runner.node.js"
It says that the file isn't executable:
sh: 1: spec/runner.node.js: Permission denied
npm ERR! Test failed. See above for more details.
npm ERR! not ok code 0
If I set the file as executable it then says:
spec/runner.node.js: 1: spec/runner.node.js: Syntax error: word unexpected (expecting ")")
npm ERR! Test failed. See above for more details.
npm ERR! not ok code 0
while it still runs correctly with "node spec/runner.node.js"
The file is this:
console.log("Running Knockout tests in Node.js");
var fs = require('fs');
var jasmine = require('./lib/jasmine-1.2.0/jasmine');
// export jasmine globals
for (var key in jasmine) {
global[key] = jasmine[key];
}
// add our jasmine extensions to the exported globals
require('./lib/jasmine.extensions');
// export ko globals
if (process.argv.length > 2 && process.argv[2] == '--source') {
// equivalent of ../build/knockout-raw.js
global.DEBUG = true;
global.ko = global.koExports = {};
global.knockoutDebugCallback = function(sources) {
sources.unshift('build/fragments/extern-pre.js');
sources.push('build/fragments/extern-post.js');
eval(sources.reduce(function(all, source) {
return all + '\n' + fs.readFileSync(source);
}, ''));
};
require('../build/fragments/source-references');
} else {
global.ko = require('../build/output/knockout-latest.js');
}
// reference behaviors that should work out of browser
require('./arrayEditDetectionBehaviors');
require('./asyncBehaviors');
require('./dependentObservableBehaviors');
require('./expressionRewritingBehaviors');
require('./extenderBehaviors');
require('./mappingHelperBehaviors');
require('./observableArrayBehaviors');
require('./observableBehaviors');
require('./subscribableBehaviors');
// get reference to jasmine runtime
var env = jasmine.jasmine.getEnv();
// create reporter to return results
function failureFilter(item) {
return !item.passed();
}
env.addReporter({
reportRunnerResults:function (runner) {
var results = runner.results();
runner.suites().map(function (suite) {
// hack around suite results not having a description
var suiteResults = suite.results();
suiteResults.description = suite.description;
return suiteResults;
}).filter(failureFilter).forEach(function (suite) {
console.error(suite.description);
suite.getItems().filter(failureFilter).forEach(function (spec) {
console.error('\t' + spec.description);
spec.getItems().filter(failureFilter).forEach(function (expectation) {
console.error('\t\t' + expectation.message);
});
});
});
console.log("Total:" + results.totalCount + " Passed:" + results.passedCount + " Failed:" + results.failedCount);
process.exit(results.failedCount);
}
});
// good to go
env.execute();

Add
#/usr/bin/env node
as the first line in your file. This way, when run as an executable your OS will know that it shall use Node.js to run it (to be exactly: your OS will know that it shall use the first application called node to execute your script).