doc(npm): add documentation for installing npm packages behind the proxy with its affiliated sidebar hyperlink entry components accordingly

docs/.vitepress/config/sidebar.ts

@@ -18,6 +18,10 @@ export const sidebar: DefaultTheme.Config['sidebar'] = {
                     text: 'Git push results in "Authentication Failed"',
                     link: '/development/git-push-authentication-failed',
                 },
+                {
+                    text: 'Installing NPM Packages Behind Proxy',
+                    link: '/development/installing-npm-package-behind-proxy'
+                }
             ],
         },
         {

docs/development/installing-npm-package-behind-proxy.md

@@ -0,0 +1,36 @@
+# Installing NPM Packages Behind Proxy
+
+On a recent assignment, I needed to install npm behind a corporate proxy. I had already set the environment variables `HTTP_PROXY` and `HTTPS_PROXY`. Other command line utilities, like ruby gems, recognized these environment variables. Npm did not.
+
+After some googling, I found the following way to configure the proxy for npm.
+
+```bash
+# npm
+npm config set proxy <http://127.0.0.1:7890>
+npm config set https-proxy <http://127.0.0.1:7890>
+
+# yarn
+yarn config set proxy <http://127.0.0.1:7890>
+yarn config set https-proxy <http://127.0.0.1:7890>
+```
+
+If you need to specify credentials, they can be passed in the url using the following syntax.
+
+```
+[<http://user_name:password@proxy.company.com:8080>](<http://user_name:password@proxy.company.com:8080/>)
+```
+
+Further exploration of the [npm config documentation](https://npmjs.org/doc/config.html) showed that the `npm config set` command sets the proxy configuration in your `.npmrc` file. You can also set the proxy configuration as a command line argument or environment variable.
+
+Configuration parameters can be specified using `--` when executing npm. So the proxy could also be specified as follows.
+
+```bash
+npm --https-proxy=http://proxy.company.com:8080 -g install karma
+```
+
+To pass configurattion parameters to npm as environment variables, they must be prefixed with `npm_config_`. The proxy configuration could be set with environment variables as follows.
+
+```bash
+export npm_config_proxy <http://proxy.company.com:8080>
+export npm_config_https_proxy <http://proxy.company.com:8080>
+```