⭐ Typescript re-write using robb-j/ts-node-base

.editorconfig

@@ -1,4 +1,7 @@
-# Editor config - For sharing IDE prefs ~ https://editorconfig.org/
+#
+# Editor config, for sharing IDE preferences ~ https://editorconfig.org/
+#
+
 root = true
 
 [*]

.gitignore

@@ -1,5 +1,9 @@
+#
+# Ignore files from git source control
+#
+
 node_modules
 coverage
 .DS_Store
-.nyc_output
 *.env
+dist

.prettierignore

@@ -0,0 +1,7 @@
+#
+# Files for prettier to ignore
+#
+
+dist
+coverage
+node_modules

README.md

@@ -1,16 +1,56 @@
 # Valid Environment
 
+Check your node environment is set up just right and fail if variables aren't set.
+A super slim, zero dependency package for checking environment variables aren't undefined.
+
+> NOTE: It checks variables for `=== undefined` so if a variable is set to
+> another [falsy value](https://developer.mozilla.org/en-US/docs/Glossary/Falsy)
+> it will pass the check.
+> This means you can safely set variables to those falsy values if you want to.
+
+## Package motivation
+
+I created this package because lots of my npm-based projects needed to check certain environment variables were set and I didn't want to keep copying the code from repo to repo.
+
+Its designed to be as light as possible so there are no dependancies and minimal code, I'm just interested in repurposing this same code quickly.
+
+I also like to make my code human-readable so the function names are longer but hopefully have more meaning to the reader.
+
+## Usage
+
+There are three ways of using this package, it also provides
+[type definitions](/dist/index.d.ts) so you can easily use it in TypeScript.
+
+### 1 - Exit the current process
+
+This is the primary use case, you can put this snippet during the startup
+of your project and quickly assert all the required environment variables are set.
+
+**in JavaScript**
+
 ```js
-const validateEnv = require('valid-env')
+const { validateEnv } = require('valid-env')
 
-validateEnv([ 'DATABASE_URL', 'SERVICE_KEY', 'NUM_CARROTS' ])
+validateEnv(['MYSQL_URI', 'SERVICE_KEY', 'NUM_CARROTS'])
 
 // exit 1: Missing environment variables: SERVICE_KEY, NUM_CARROTS
 ```
 
-Check your node environment is set up just right and fail if variables aren't set.
+**in TypeScript**
+
+```ts
+import validateEnv from 'valid-env'
+
+validateEnv(['MYSQL_URI', 'SERVICE_KEY', 'NUM_CARROTS'])
+
+// exit 1: Missing environment variables: SERVICE_KEY, NUM_CARROTS
+```
 
-Or if you want, place this in your **package.json**:
+### 2 - As a package.json script
+
+An alternate case is to use a pre-x script in your `package.json`
+to check environment variables there.
+This works when you have this package as a dependency.
 
 ```json
 {
@@ -19,3 +59,28 @@ Or if you want, place this in your **package.json**:
   }
 }
 ```
+
+### 3 - Throwing errors
+
+You can also use the internal `#checkVariables` method to only throw an error,
+if you don't want to exit the process.
+
+**in JavaScript**
+
+```js
+const { checkVariables } = require('valid-env')
+
+checkVariables(['AWS_ACCESS_KEY_ID', 'AWS_SECRET_ACCESS_KEY', 'MYSQL_URI'])
+```
+
+**in TypeScript**
+
+```ts
+import { checkVariables } from 'valid-env'
+
+checkVariables(['AWS_ACCESS_KEY_ID', 'AWS_SECRET_ACCESS_KEY', 'MYSQL_URI'])
+```
+
+---
+
+> This project was setup with [robb-j/ts-node-base](https://github.com/robb-j/ts-node-base)