Npm start doesn't work

Ahsan_72923 · August 21, 2019, 6:33am

I exactly followed the readme lecture, everything went fine, but when I used the npm start command, I got the following error. Even though after hassling using google, I’m still unable to start the application:

D:\Learn\mflix-js>npm start

server@1.0.0 start D:\Learn\mflix-js
nodemon -L ./index.js

[nodemon] 1.19.1
[nodemon] to restart at any time, enter rs
[nodemon] watching: .
[nodemon] starting node ./index.js
internal/modules/cjs/loader.js:626
throw err;
^

Error: Cannot find module ‘babel-core/register’
Require stack:
D:\Learn\mflix-js\index.js
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:623:15)
at Function.Module._load (internal/modules/cjs/loader.js:527:27)
at Module.require (internal/modules/cjs/loader.js:681:19)
at require (internal/modules/cjs/helpers.js:16:16)
at Object. (D:\Learn\mflix-js\index.js:1:1)
at Module._compile (internal/modules/cjs/loader.js:774:30)
at Object.Module._extensions…js (internal/modules/cjs/loader.js:785:10)
at Module.load (internal/modules/cjs/loader.js:641:32)
at Function.Module._load (internal/modules/cjs/loader.js:556:12)
at Function.Module.runMain (internal/modules/cjs/loader.js:837:10) {
code: ‘MODULE_NOT_FOUND’,
requireStack: [ ‘D:\Learn\mflix-js\index.js’ ]
}
[nodemon] app crashed - waiting for file changes before starting…

Even I tried installing bable using

npm install @babel/core --save

and it didn’t worked and said

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Ahsan Ali\AppData\Roaming\npm-cache_logs\2019-08-21T06_16_34_572Z-debug.log

Fabii_08776 · August 21, 2019, 9:20am

I’m in the same situation

kanikasingla · August 21, 2019, 10:13am

Please take a look at the following post:

Let me know if you are still facing issue.

Kanika

Ahsan_72923 · August 21, 2019, 1:37pm

have you got any solution yet ?

gudmundurb · August 22, 2019, 12:46am

Ahsan_72923:
Check this thread here, if you are still encountering this problem :

npm-install-error-and-npm-start-cannot-find-module

Fabii_08776 · August 22, 2019, 12:53am

Yes, I resolved as per the suggestion “… To resolve this I deleted the package-lock.json file, ran npm audit fix and npm install …”

Ahsan_72923 · August 22, 2019, 5:00am

after trying your commands, I’m getting Cannot read property 'split' of null error

Fabii_08776 · August 22, 2019, 7:51am

Read the topic of this link until the end have another suggestion if you are using windows:

Ahsan_72923 · August 22, 2019, 10:30am

I don’t know how it started, but eventually after rolling through different threads above, it somehow got to start.
Now, although it’s working fine, but I’m still getting a warning
(node:7852) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to MongoClient.connect. listening on port 5000
Is it safe to ignore the above warning ? or I need to do something to remove this.
And thanks for helping me out all the guys out there.

gudmundurb · August 22, 2019, 1:10pm

If it works, then don’t worry about it

Just do your tickets and cross your fingers

I am at 3rd chapter and I just did that yarn thing … I have a github warning about some mem leak component, not so worried, this is a learning environment, it is never going to be a life app.

happy coding … but on the side note, it can be a good practice for future projects to update package file and make it your goal to get error free program start, but maybe after this course is over.

regards,

Ahsan_72923 · August 22, 2019, 1:42pm

Alright, thanks for your response.
I’m at the last step of README tutorial, my application is running fine and I check it through browser too.
Now then I run the npm test -t connection-pooling.test.js command, I get the following error

server@1.0.0 test D:\Learn\mflix-js
jest --passWithNoTests “connection-pooling.test.js”

Determining test suites to run…Setup Mongo Connection
(node:17756) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to MongoClient.connect.
FAIL test/connection-pooling.test.js
Connection Pooling
× Connection pool size is 50 (317ms)

● Connection Pooling › Connection pool size is 50

expect(received).toBe(expected) // Object.is equality

Expected: 50
Received: undefined

Difference:

  Comparing two different types of values. Expected number but received undefined.

   8 |   test("Connection pool size is 50", async () => {
   9 |     const response = await MoviesDAO.getConfiguration()
> 10 |     expect(response.poolSize).toBe(50)
     |                               ^
  11 |   })
  12 | })
  13 |

  at toBe (test/connection-pooling.test.js:10:31)
  at tryCatch (node_modules/babel-runtime/node_modules/regenerator-runtime/runtime.js:62:40)
  at Generator.invoke [as _invoke] (node_modules/babel-runtime/node_modules/regenerator-runtime/runtime.js:296:22)
  at Generator.prototype.<computed> [as next] (node_modules/babel-runtime/node_modules/regenerator-runtime/runtime.js:114:21)
  at step (node_modules/babel-runtime/helpers/asyncToGenerator.js:17:30)
  at node_modules/babel-runtime/helpers/asyncToGenerator.js:28:13

Test Suites: 1 failed, 1 total
Tests: 1 failed, 1 total
Snapshots: 0 total
Time: 5.739s, estimated 6s
Ran all test suites matching /connection-pooling.test.js/i.
Teardown Mongo Connection

What to do now ?

kanikasingla · August 22, 2019, 1:44pm

You don’t need to run this test yet! This was just for explaining on how to run the unit tests.

Kanika

MANJESHA_34722 · August 22, 2019, 1:53pm

I am still getting the crash report whenever i tried npm start[quote=“Ahsan_72923, post:1, topic:32394, full:true”]
I exactly followed the readme lecture, everything went fine, but when I used the npm start command, I got the following error. Even though after hassling using google, I’m still unable to start the application:

D:\Learn\mflix-js>npm start

server@1.0.0 start D:\Learn\mflix-js
nodemon -L ./index.js

[nodemon] 1.19.1
[nodemon] to restart at any time, enter rs
[nodemon] watching: .
[nodemon] starting node ./index.js
internal/modules/cjs/loader.js:626
throw err;
^

Error: Cannot find module ‘babel-core/register’
Require stack:
D:\Learn\mflix-js\index.js
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:623:15)
at Function.Module._load (internal/modules/cjs/loader.js:527:27)
at Module.require (internal/modules/cjs/loader.js:681:19)
at require (internal/modules/cjs/helpers.js:16:16)
at Object. (D:\Learn\mflix-js\index.js:1:1)
at Module._compile (internal/modules/cjs/loader.js:774:30)
at Object.Module._extensions…js (internal/modules/cjs/loader.js:785:10)
at Module.load (internal/modules/cjs/loader.js:641:32)
at Function.Module._load (internal/modules/cjs/loader.js:556:12)
at Function.Module.runMain (internal/modules/cjs/loader.js:837:10) {
code: ‘MODULE_NOT_FOUND’,
requireStack: [ ‘D:\Learn\mflix-js\index.js’ ]
}
[nodemon] app crashed - waiting for file changes before starting…

Natac13 · August 22, 2019, 2:18pm

So the M220 JavaScript project uses Babel v6.x atm and therefore I do not think installing anything with @babel will work since they use that nomenclature for v7+.

    "babel-core": "^6.26.3",
    "babel-plugin-transform-runtime": "^6.23.0",
    "babel-preset-env": "^1.7.0",
    "babel-preset-stage-1": "^6.24.1",
    "babel-register": "^6.26.0",
    "babel-runtime": "^6.26.0",

I have gone ahead an downloaded the handout zip file. Unpacked it, ran npm i then npm audit fix, change the name of the correct environment file and set the URI to my cluster. And had no problems with npm start

Perhaps it maybe a good idea to completely remove the folder you created for the course and start again. With

Create folder called M220, cd into it
Download zip file into that folder
Unpack
run npm install
run npm audit fix
set up .env file
try npm start again.

If there are still issues let me know

Ahsan_72923 · August 22, 2019, 2:33pm

I don’t think, it will work, because I already have tried all of the above steps.

Natac13 · August 22, 2019, 2:46pm

Well perhaps you should try the steps, making sure to completely delete the entire folder and start again. I have done it 3 times with success each time just to make sure I am not leading you astray. And if not I apologize.

And lastly you can try to go into the index.js file at the top level and change the following command.

# from
require("babel-core/register")
# to 
require('babel-register')

As per https://babeljs.io/docs/en/6.26.3/babel-register

I do hope we can get this working for you

Ahsan_72923 · August 22, 2019, 5:01pm

@natac13 thanks you, I just got it to work

Natac13 · August 22, 2019, 8:57pm

Can I ask what did the trick for any future student with same issue?

MANJESHA_34722 · August 23, 2019, 5:37am

again getting same error

MongoParseError: URI malformed, cannot be parsed
at parseConnectionString (C:\mfix\node_modules\mongodb\lib\core\uri_parser.js:502:21)
at connect (C:\mfix\node_modules\mongodb\lib\operations\connect.js:266:3)
at ConnectOperation.execute (C:\mfix\node_modules\mongodb\lib\operations\connect.js:191:5)
at C:\mfix\node_modules\mongodb\lib\operations\execute_operation.js:109:26
at new Promise ()
at executeOperation (C:\mfix\node_modules\mongodb\lib\operations\execute_operation.js:102:10)
at MongoClient.connect (C:\mfix\node_modules\mongodb\lib\mongo_client.js:216:10)
at Function.MongoClient.connect (C:\mfix\node_modules\mongodb\lib\mongo_client.js:379:22)
at Object. (C:/mfix/src/index.js:23:13)
at Module._compile (internal/modules/cjs/loader.js:868:30)
[nodemon] app crashed - waiting for file changes before starting…

Ahsan_72923 · August 23, 2019, 6:03am

Try the steps that @natac13 told, that worked fine for me.