[breaking change] Use dotenv.parse(), replace options.loadDotEnv with…

… options.dotEnvPath

This is a breaking change because the env vars in the `.env` file will
no longer be added to `process.env`. See discussion on #25

README.md

@@ -21,12 +21,16 @@ positional arguments:
 * `environment` - An object containing your env vars (eg. `process.env`)
 * `validators` - An object that specifies the format of required vars.
 * `options` - An (optional) object, which supports the following keys:
-    * `strict` - If true, the output of `cleanEnv` will *only* contain the env 
-                 vars that were specified in the `validators` argument.
+    * `strict` - (default: `false`) If true, the output of `cleanEnv` will *only*
+                 contain the env vars that were specified in the `validators` argument.
     * `reporter` - Pass in a function to override the default error handling and
                    console output. See `lib/reporter.js` for the default implementation.
     * `transformer` - A function used to transform the cleaned environment object
                       before it is returned from `cleanEnv`
+    * `dotEnvPath` - (default: `'.env'`) Path to the file that is parsed by
+                     [dotenv](https://github.com/motdotla/dotenv) to
+                     optionally load more env vars at runtime. Pass `null` if you want
+                     to skip `dotenv` processing entirely and only load from `process.env`.
 
 By default, `cleanEnv()` will log an error message and exit if any required
 env vars are missing or invalid.

index.js

@@ -1,3 +1,4 @@
+const fs = require('fs')
 const dotenv = require('dotenv')
 const { EnvError, EnvMissingError, makeValidator,
         bool, num, str, json, url, email } = require('./lib/validators')
@@ -36,8 +37,17 @@ function formatSpecDescription(spec) {
     return `${spec.desc}${egText}${docsText}` || ''
 }
 
-function extendWithDotEnv(inputEnv) {
-    const { parsed } = dotenv.config()
+// Extend an env var object with the values parsed from a ".env"
+// file, whose path is given by the second argument.
+function extendWithDotEnv(inputEnv, dotEnvPath = '.env') {
+    let dotEnvBuffer = null
+    try {
+        dotEnvBuffer = fs.readFileSync(dotEnvPath)
+    } catch (err) {
+        if (err.code === 'ENOENT') return inputEnv
+        throw err
+    }
+    const parsed = dotenv.parse(dotEnvBuffer)
     return extend(parsed, inputEnv)
 }
 
@@ -46,7 +56,9 @@ function cleanEnv(inputEnv, specs = {}, options = {}) {
     let defaultNodeEnv = ''
     const errors = {}
     const shouldLoadDotEnv = (options.loadDotEnv !== false)
-    const env = shouldLoadDotEnv ? extendWithDotEnv(inputEnv) : inputEnv
+    const env = (options.dotEnvPath !== null)
+        ? extendWithDotEnv(inputEnv, options.dotEnvPath)
+        : inputEnv
     const varKeys = Object.keys(specs)
 
     // If validation for NODE_ENV isn't specified, use the default validation:

tests/test_dotenv.js

@@ -26,7 +26,16 @@ test('.env test in strict mode', () => {
     assert.deepEqual(env, { MYNUM: 4 })
 })
 
-test('can opt out of dotenv with loadDotEnv=false', () => {
-    const env = cleanEnv({ FOO: 'bar' }, {}, { loadDotEnv: false })
+test('can opt out of dotenv with dotEnvPath=null', () => {
+    const env = cleanEnv({ FOO: 'bar' }, {}, { dotEnvPath: null })
     assert.deepEqual(env, { FOO: 'bar' })
 })
+
+test('can use a custom .env file name', () => {
+    const path = '.custom-env'
+    fs.writeFileSync(path, 'CUSTOM=hi')
+
+    const env = cleanEnv({ FOO: 'bar' }, {}, { dotEnvPath: path })
+    assert.deepEqual(env, { FOO: 'bar', CUSTOM: 'hi' })
+    fs.unlinkSync(path)
+})