NPM Installation Issue: JSON Parsing Error with Webpack Plugin

Other Questions NPM
1

Problem Overview

I am facing an issue when I attempt to create a new Angular 5 project. Each time I run the installation command for the Angular CLI globally, I encounter a JSON parsing error that halts the process.

My Setup

  • Node version: 8.9.2
  • NPM version: 5.5.1

Command I Execute

npm install -g @angular/cli

Received Error

npm ERR! Unexpected end of JSON input while parsing near '...nt-webpack-plugin':'0'
npm ERR! You can find the complete log of this operation at:
npm ERR!     C:\Users\Aashitec\AppData\Roaming\npm-cache\_logs\2017-12-06T13_10_10_729Z-debug.log

This seems to occur when npm tries to read some JSON data related to a specific webpack plugin. I tried clearing the npm cache, yet the issue continues. Has anyone else experienced this error? What could be the underlying cause of this JSON parsing problem during the installation?

2

Hit this same problem with Node 8.x last year. Network interruptions during downloads leave broken JSON files in npm’s cache. After clearing cache, run npm config set registry https://registry.npmjs.org/ to make sure you’re hitting the right registry, then try installing with --verbose to see exactly where it breaks. If that doesn’t work, switch to yarn for the global install - yarn global add @angular/cli - since it handles corrupted cache better. Usually it’s flaky internet or antivirus messing with downloads.

3

Hit this same error two months back setting up my dev environment on Windows. Wasn’t just the package cache - turned out to be corrupted registry entries in npm’s metadata cache. npm cache clean --force didn’t fix it. Had to manually delete the whole npm-cache folder from AppData, then run npm cache verify to rebuild everything. Angular CLI installed fine after that. Pretty sure the corruption happened when a previous package install got interrupted or timed out.

4

same thing happened to me a few weeks back. update npm first: npm install -g npm@latest, then try installing angular again. old npm versions sometimes can’t handle newer package metadata. if it still doesn’t work, use npx instead: npx @angular/cli new my-project - no global install needed.