NPM is giving me an error using npm install - node.js

Question

A friend shared with me a theme he is developing for WordPress, and I cloned his repo in my /themes folder, first thing I tried was to run "npm install" in the theme folder in order to get gulp and other npm cool features.
This is what it returns:
$ npm install
npm ERR! code EINTEGRITY
npm ERR! sha1-fjL3W0e4epHQRhHxvxQQmsAGUdc= integrity checksum failed when using sha1: wanted sha1-fjL3W0e4epHQRhHxvxQQmsAGUdc= but got sha512-kV/CThkXo6xyFEZUugw/+pIOywXcDbFYgSct5cT3gqlbkBE1SJdwy6UQoZvodiWF/ckQLZyDE/Bu1M6gVu5lVw== sha1-fjL3W0E4EpHQRhHxvxQQmsAGUdc=. (36808 bytes)
npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\rinor\AppData\Roaming\npm-cache\_logs\2020-04-04T17_30_54_859Z-debug.log
After trying installing it globally it gave me back the same error so I came up with uninstalling node.js from my pc and then download and install the LTS version (12.16.1). Rebooted, tested and it seemed to work as I tried typing "node -v" && "npm -v". But when I return to my theme and go for "npm install" it gives me the same error.
Here is my package.json content
{
"name": "ruce-theme",
"version": "1.0.0",
"description": "A starter theme",
"scripts": {
"watch": "gulp watch"
},
"dependencies": {
"bootstrap": "^4.0.0-beta.3",
"jquery": "^3.2.1",
"npm": "^6.4.1",
"slick-carousel": "^1.8.1"
},
"devDependencies": {
"#babel/core": "^7.3.3",
"#babel/preset-env": "^7.3.1",
"#babel/preset-react": "^7.0.0",
"babel-core": "^6.25.0",
"babel-loader": "^8.0.5",
"babel-plugin-transform-react-jsx": "^6.24.1",
"babel-preset-env": "^1.6.0",
"cross-env": "^5.0.1",
"css-loader": "^2.1.0",
"extract-text-webpack-plugin": "^4.0.0-beta.0",
"file-loader": "^3.0.1",
"gulp": "^4.0.0",
"gulp-babel": "^8.0.0-beta.2",
"gulp-clean-css": "^3.9.1",
"gulp-clone": "^1.1.4",
"gulp-concat": "^2.6.1",
"gulp-cssnano": "^2.1.2",
"gulp-ignore": "^2.0.2",
"gulp-imagemin": "^4.0.0",
"gulp-merge": "^0.1.1",
"gulp-plumber": "^1.2.0",
"gulp-rename": "^1.2.2",
"gulp-rimraf": "^0.2.2",
"gulp-sass": "^3.1.0",
"gulp-sequence": "^0.4.6",
"gulp-sourcemaps": "2.6.2",
"gulp-uglify": "^3.0.0",
"gulp-watch": "^4.3.11",
"node-sass": "^4.11.0",
"sass-loader": "^7.1.0",
"style-loader": "^0.23.1",
"webpack": "^4.29.0",
"webpack-cli": "^3.2.1"
},
"license": "ISC"
}
These are the erros that the debug shows
20111 error code EINTEGRITY
20112 error sha1-fjL3W0e4epHQRhHxvxQQmsAGUdc= integrity checksum failed when using sha1: wanted sha1-fjL3W0e4epHQRhHxvxQQmsAGUdc= but got sha512-kV/CThkXo6xyFEZUugw/+pIOywXcDbFYgSct5cT3gqlbkBE1SJdwy6UQoZvodiWF/ckQLZyDE/Bu1M6gVu5lVw== sha1-fjL3W0E4EpHQRhHxvxQQmsAGUdc=. (36808 bytes)
20113 verbose exit [ 1, true ]

Answer 1

You don't mention whether you had package-lock.json or not. In some cases the following might help. But first make sure you understand what's going on. npm tells you that the checksum from https://registry.npm.org doesn't match the one from package-lock.json. Either it changed in the registry, or...
Solution Consider the line from the output:
npm ERR!
sha1-fjL3W0e4epHQRhHxvxQQmsAGUdc=
integrity checksum failed when using sha1: wanted
sha1-fjL3W0e4epHQRhHxvxQQmsAGUdc=
but got
sha512-kV/CThkXo6xyFEZUugw/+pIOywXcDbFYgSct5cT3gqlbkBE1SJdwy6UQoZvodiWF/ckQLZyDE/Bu1M6gVu5lVw== sha1-fjL3W0E4EpHQRhHxvxQQmsAGUdc=
. (36808 bytes)
Find the package in package-lock.json by the first two integrity checksums (sha1-...), and put the third one (sha512-...) into its "integrity" field.
More on it here.