Difficulty solving "sh: <npm package name> command not found" with npm run <npm package name>

Question

I've been adding npm modules to my project for the first time (jshint, optimg, jpgo). I notice that some projects, when I do npm run [name], give a result of "sh: [name]: command not found."

I can't figure out why those don't work, but the other npm installs do. All these are installed locally; I can see the install by looking in the /node_modules folder in my project root and verify them with npm ls.

The latest package that gets this error is html-minify. My package.json looks like this (and validates at http://jsonlint.com/):

{
    "name": "npmTest",
    "devDependencies": {
        "jshint": "latest",
        "optimg": "latest",
        "jpgo": "latest",
        "ycssmin": "latest",
        "html-minify": "latest"
    },
    "scripts": {
        "lint": "jshint **.js",
        "png": "optimg",
        "jpg": "jpgo",
        "css": "ycssmin **.css",
        "html": "html-minify"

    }
}

I tried "html-minify **.html" with the same resulting "not found" error.

Why would I get "sh: [npm package name]: command not found"? I've read the other threads, and because the other modules work, I doubt that I need to add anything to my PATH, or start a server, or install globally.

Fuller error message (for html5-lint):

$ npm run html

> npmTest@ html /Users/Steve/Documents/APPS/Test_Apps/npmTest
> html5-lint

sh: html5-lint: command not found

npm ERR! npmTest@ html: `html5-lint`
npm ERR! Exit status 127
npm ERR! 
npm ERR! Failed at the npmTest@ html script.
npm ERR! This is most likely a problem with the npmTest package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     html5-lint
npm ERR! You can get their info via:
npm ERR!     npm owner ls npmTest
npm ERR! There is likely additional logging output above.
npm ERR! System Darwin 14.1.0
npm ERR! command "node" "/usr/local/bin/npm" "run" "html"
npm ERR! cwd /Users/Steve/Documents/APPS/Test_Apps/npmTest
npm ERR! node -v v0.10.25
npm ERR! npm -v 1.3.24
npm ERR! code ELIFECYCLE
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /Users/Steve/Documents/APPS/Test_Apps/npmTest/npm-debug.log
npm ERR! not ok code 0

Answer 1

so short answer to run npm package commands locally

npm i install cowsay -d

then use

npx cowsay I am working locally

output should be

______
< I am working locally  >
 ------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

on the other hand installing npm packages globaly on linux has problems with addministrator and node-module location

so best practice to get global packges to work normally is to install NVM first

sudo apt install curl
curl https://raw.githubusercontent.com/creationix/nvm/master/install.sh | bash
source ~/.profile

then once nvm is installed install from nvm node

nvm install node 

or a specific version

nvm install 12.18.3

now installing global packages and running them is simple

npm install -g cowsay

cowsay I am working globaly

will output

______
< I am working  >
 ------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

now global packages are working fine and local packages can be run from the directory of the project using npx.