From eb7bc463316ecf62c0ccf40ee219f5e60fc20223 Mon Sep 17 00:00:00 2001
From: Igor Ovsiannikov <garek@mail.ru>
Date: Sat, 21 Feb 2015 17:26:02 +0300
Subject: [PATCH 1/2] feat(error,warn) Throw or warn on missing vars

Added new flags "error" and "warn" that could be passed to envify.

If error is passed, then envify will throw descriptive error if any
environment variable is not defined.

If warn is passed, then envify will print message to terminal in same
circumstances.
---
 test.js     | 36 ++++++++++++++++++++++++++++++++++++
 visitors.js |  7 +++++++
 2 files changed, 43 insertions(+)

diff --git a/test.js b/test.js
index 8ed7ed3..c045957 100644
--- a/test.js
+++ b/test.js
@@ -153,3 +153,39 @@ test('-t [ envify purge --argument ]', function(t) {
       , 'var y = process.env.argument'
     ].join('\n'))
 })
+
+test('-t [ envify error ]', function(t) {
+  var stream = envify()
+  var buffer = ''
+  var caughtError = false;
+
+  stream(__filename, { _: ['error'] })
+    .on('data', function(d) { buffer += d })
+    .on('error', function (e) {
+      t.ok(e, 'throws error if env variable is missing');
+      t.end();
+    })
+    .on('end', function () {
+      t.fail('should throw error if env variable is missing')
+      t.end();
+    })
+    .end('var x = process.env.MISSING_VAR')
+})
+
+test('-t [ envify error --argument]', function(t) {
+  var stream = envify()
+  var buffer = ''
+  var caughtError = false;
+
+  stream(__filename, { _: ['error'], argument: 1 })
+    .on('data', function(d) { buffer += d })
+    .on('error', function (e) {
+      t.fail(e, 'should not throw if env variable is defined');
+      t.end();
+    })
+    .on('end', function () {
+      t.pass('does not throw error if env variable is defined')
+      t.end();
+    })
+    .end('var x = process.env.argument')
+})
diff --git a/visitors.js b/visitors.js
index 4abff9f..06a576a 100644
--- a/visitors.js
+++ b/visitors.js
@@ -1,9 +1,12 @@
 var Syntax = require('jstransform').Syntax
 var utils = require('jstransform/src/utils')
+var util = require('util')
 
 function create(envs) {
   var args  = [].concat(envs[0]._ || []).concat(envs[1]._ || [])
   var purge = args.indexOf('purge') !== -1
+  var error = args.indexOf('error') !== -1
+  var warn = args.indexOf('warn') !== -1
 
   function visitProcessEnv(traverse, node, path, state) {
     var key = node.property.name
@@ -18,6 +21,10 @@ function create(envs) {
 
     if (purge) {
       replaceEnv(node, state, undefined)
+    } else if (error || warn) {
+      var msg = util.format('envify did not find value for "%s" variable', node.property.name);
+      if(error) throw new Error(msg);
+      else console.log('WARN: ', msg);
     }
 
     return false

From fed1cb6cc1f6ce43311b986f23241c64b215f7d3 Mon Sep 17 00:00:00 2001
From: Igor Ovsiannikov <garek@mail.ru>
Date: Sat, 21 Feb 2015 17:44:16 +0300
Subject: [PATCH 2/2] docs: mention error and warn in README

---
 README.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/README.md b/README.md
index 37f2c65..d36536f 100644
--- a/README.md
+++ b/README.md
@@ -135,6 +135,15 @@ b.transform(envify({
 }))
 ```
 
+## Throw or Warn if env variable is missing ##
+
+May be you want to be sure, that all `process.env` were replaced. There is two
+additional subargs to help you with that: `error` and `warn`.
+
+You can use it in the same way as `purge` subarg.
+
+Keep in mind that `purge`, `error` and `warn` are mutual exclusive.
+
 ## Contributors ##
 
 * [hughsk](http://github.com/hughsk)