Find out what file is requiring another file in Node - node.js

The title says pretty much what I need to do.
I have a module in node_modules which prints something to the standard output (and I don't want this to happen) but I don't find where I'm requiring this file.
I may be misunderstanding how modules are included, as I though that they must be required in order to be executed.

There are multiple ways for stuff to write to output. If it's just using console.log(), just swap in trace. Before your require() statements:
console.log = console.trace;
Then, you'll have the full trace output every time there's a log.

Using this console.log mod :
let old = console.log;
console.log = function(){
return old.apply(this,[].slice.apply(arguments).concat([(new Error()).stack.split(/\n/)[2].trim()]));
}
If you try :
console.log('I am trackable!')
You will get as output :
I am trackable! at test (/path/solution.js:5:9)
Happy hunting!

Related

how to suppress output of a function in node/typescript

I have a typescript/node application where I am calling a 3rd-party function from a package that will output a string to the console. However, I want to know if it is possible to somehow suppress any kind of output (to the console/terminal) that this function will produce. I know that adding console.log = () => {} at the top of the file can do the job, but the linting rules (which I cannot change) of my group project state that calls to console.log are not allowed. Would anyone know of a more effective way of disabling output to console, without actually making reference to console?

How can I split my code, and keep it all asynchronous?

I've been coding just as a side project for a bit, piecing together bits that other people have written (it's for a simple discord bot). I want to split my code to make it easier to problem solve and read, however whenever I try to use the code it comes up with an error saying 'SyntaxError: await is only valid in async function'.
I've tried supposedly loading the code asynchronously, loading it with require() and then making a single command asynchronous, making the entire code in the file asynchronous (it's not just one command I want to load, but a whole file. Also I'm not sure if I tried it correctly or not), using the npm async-require, and maybe some others that have been around on the internet.
//one of the solutions I've tried. This is just copy pasted from the
//answer
//file2.js
var fs = require('fs');
module.exports = function (callback) {
fs.readFile('/etc/passwd', function (err, data) {
callback(err, data);
});
};
//file1.js
require('./passwords')(function (err, passwords) {
// This code runs once the passwords have been loaded.
});
In the first file before I split it, I started it with client.on('message', async message => { and it made me able to use the await function in every command. I want to still be able to do that, but just have it a bit neater and easier to use by splitting it.
I'm trying to get this done so I can move on to a different question I asked and give one of the answers a tick. Any help would be greatly appreciated <3
Fix those awaits so that they are not inside async functions. This is a lexical issue that can be solved just by looking at the location were the error occurs. Just look for the nearest containing function to where the await is and mark it async. Repeat until the error goes away.

Puppeteer evaluate not executing required function

I've got a little app i've written with node.js and puppeteer. I'm trying to require a function from a different file into my evaluate callback, however the function never fires and causes evaluate to fail. Here is a pretty simple example, and maybe somebody can see if i'm just doing something stupid here.
Evaluate is called from File A
product = await page.evaluate( source.getProductInformation )
source.getProductInformation is defined in File B, this function fails when I call a function I require from within File B
const priceSavePercent = calculateSavePercentage(priceWasNum, priceCurrentNum)
calculateSavePercentage is simply required at the top of File B const { calculateSavePercentage } = require('../modules/helpers')
I try to console log everywhere and don't get any output to my console, and my evaluate callback doesn't return the object it's suppose to. Is there a different way i'm suppose to require dependencies into File B? I have an npm package and a constant also required in File B and both don't cause issues. Any help is greatly appreciated. Let me know if you need any more info.
The problem is that when you evaluate, you are accessing the page you are scraping javascript, not your own so that function isn't defined you could try something like this.
await page.evaluate((source) => {
source.getProductInformation();
}, source);

Netsuite: ReferenceError functionName is not defined

This is probably a stupid one but I have tried all the things I can think of. I am currently getting the below error on my client side script when I try and execute it.
Error: ReferenceError acvt_serialNumber_saveRecord is not defined
On the Script record in Netsuite I have set the saveRecord function as follows:
acvt_serialNumber_saveRecord
The code in the file is:
function acvt_serialNumber_saveRecord(){
/**do stuff */
}
I have reuploaded to code to make sure the right version was in NetSuite. I have added one character to both the script fn name and the fn name on the Script record (as a shot in the dark). I have seen in the Javascript console at runtime that the correct code is in there and I can see the exact function name (I did a ctrl+f for the "undefined" function in the code in the console to make sure spelling was all the same).
NOTHING has worked. I had this code working earlier, but the changes I made were not to this function at all.
Any help is appreciated
Another thing to check is the code that you recently changed. In particular, check for a hanging comma. IE:
var someObj = {
someProp:'somevalue',
};
The comma at the end of 'somevalue' will cause the script to fail, throwing 'undefined' errors.
Have you tried deleting the Script record in NetSuite and re-creating it?
Do you have any library included for that Client Script in netsuite ?
Provide a screen shot of your Netsuite script page
I encounter similar problem like this before, but it was because i called a function which is inside a library file
Thanks

Muting stdout and stderr during Mocha tests

I'll preface this by admitting that I'm probably doing something I shouldn't be doing. But since I'm already this deep, I might as well understand why things are happening this way.
I am using Mocha to test some Node.js code. This code uses the Winston logging library, which directly calls process.stdout.write() and process.stderr.write() (source). It works well; I have no complaints about that behavior.
However, when I unit-test this code, the output of the Mocha test runner is occasionally interspersed with lines of log output, which is ugly in some reporters (dot, bdd) and downright invalid in others (xunit). I wanted to block this output without modifying or subclassing Winston, and I wanted to avoid modifying the application itself if I could avoid it.
What I arrived at was a set of utility functions that can temporarily replace the Node builtins with a no-op function, and vice versa:
var stdout_write = process.stdout._write,
stderr_write = process.stderr._write;
function mute() {
process.stderr._write = process.stdout._write = function(chunk, encoding, callback) {
callback();
};
}
function unmute() {
process.stdout._write = stdout_write;
process.stderr._write = stderr_write;
}
Inside the various test specs, I called mute() directly before any call or assertion that produced unwanted output, and unmute() directly after. It felt a little hacky, but it worked -- not a single byte of unwanted output appeared on the console when running the tests.
Now it gets weird!
For the first time, I tried redirecting the output to a file:
mocha spec_file.js > output.txt
The unwanted output came back! Every piece of output that was sent to stdout appears in the file. Adding 2>&1, I get stderr in the file too. Nothing appears on the console in either case, though.
Why would the test code behave so differently between the two invocations? My gut guess is that Mocha is doing some sort of test to determine whether or not it's writing to a TTY, but I couldn't spot an obvious place where it changes the behavior of its writes.
Also the broader question, is there any correct way to mute stdout/stderr during tests, without wrapping all potentially-logging app code in a conditional that checks for the test environment?
See https://www.npmjs.org/package/mute
it('should shut the heck up', function (done) {
var unmute = mute()
app.options.defaults = true;
app.run(function() {
unmute();
helpers.assertFiles([
['package.json', /"name": "temp-directory"/],
['README.md', /# TEMP.Directory/]
]);
done();
});
});
I discovered a likely cause for this behavior. It does indeed have to do with whether or not stdout/stderr is a TTY.
When the script runs in a console, these are both TTYs, and process.stdout and process.stderr appear to be instances of tty.WriteStream and not, as I originally assumed, a stream.Writable. As far as my interactions went, the two classes really weren't that different -- both had public write() methods which called internal _write() methods, and both shared the same method signatures.
When piped to a file, things got a little different. process.stdout and process.stderr were instances of a different class that wasn't immediately familiar. Best I can figure, it's a fs. SyncWriteStream, but that's a stab in the dark. Anyway, this class doesn't have a _write() method, so trying to override it was pointless.
The solution was to move one level higher and do my muting with write() instead of _write(). It does the same thing, and it does it consistently regardless of where the output is going.

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