Add getenv.multi() method.

It allows you to get multiple env vars in one go:

    var config = getenv.multi({
      foo: "FOO",
      bar: ["BAR", "defaultval"],
      baz: ["BAZ", "defaultval", "string"],
      quux: ["QUUX", undefined, "integer"]
    });

For convenience, `getenv({...});` shortcuts to getenv.multi({...});
without breaking `getenv("foo");`

Author: janl

lib/getenv.js

@@ -1,3 +1,5 @@
+var util = require("util");
+
 function _value(varName, fallback) {
   var value = process.env[varName];
   if (value === undefined) {
@@ -47,8 +49,12 @@ var convert = {
 
 function converter(type) {
   return function(varName, fallback) {
-    var value = _value(varName, fallback);
-    return convert[type](value);
+    if(typeof varName == 'string') { // default
+      var value = _value(varName, fallback);
+      return convert[type](value);
+    } else { // multibert!
+      return getenv.multi(varName);
+    }
   };
 };
 
@@ -67,4 +73,29 @@ getenv.array = function array(varName, type, fallback) {
   return value.split(/\s*,\s*/).map(convert[type]);
 };
 
+getenv.multi = function multi(spec) {
+  var key, value;
+  var result = {};
+  for(var key in spec) {
+    var value = spec[key];
+    if(util.isArray(value)) { // default value & typecast
+      switch(value.length) {
+        case 1: // no default value
+        case 2: // no type casting
+          result[key] = getenv(value[0], value[1]); // dirty, when case 1: value[1] is undefined
+        break;
+        case 3: // with typecast
+          result[key] = getenv[value[2]](value[0], value[1]);
+          break;
+        default: // wtf?
+          throw('getenv.multi(): invalid spec');
+          break;
+      }
+    } else { // value or throw
+      result[key] = getenv(value);
+    }
+  }
+  return result;
+};
+
 module.exports = getenv;

test/getenv.js

@@ -375,6 +375,112 @@ tests['getenv.array() nonexistent type'] = function() {
   });
 };
 
+tests['getenv.multi([string]) multiple env vars'] = function() {
+  var spec = {
+    foo: 'TEST_GETENV_STRING' // throws when nonexistant
+  };
+  var config = getenv.multi(spec);
+  var expect = {
+    foo: process.env.TEST_GETENV_STRING
+  };
+  assert.deepEqual(expect, config);
+};
+
+tests['getenv([string]) multiple env vars shortcut'] = function() {
+  var spec = {
+    foo: 'TEST_GETENV_STRING' // throws when nonexistant
+  };
+  var config = getenv(spec);
+  var expect = {
+    foo: process.env.TEST_GETENV_STRING
+  };
+  assert.deepEqual(expect, config);
+};
+
+
+tests['getenv.multi([string/throw]) multiple env vars'] = function() {
+  var spec = {
+    foo: 'TEST_GETENV_NONEXISTENT' // throws when nonexistant
+  };
+  assert.throws(function() {
+    var config = getenv.multi(spec);
+  });
+};
+
+tests['getenv.multi([string/typecast]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_STRING', undefined, 'string']
+  };
+  var config = getenv.multi(spec);
+  var expect = {
+    foo: process.env.TEST_GETENV_STRING
+  };
+  assert.deepEqual(expect, config);
+};
+
+tests['getenv.multi([string/typecast/defaultval]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_NONEXISTENT', 'default', 'string'] // throws when nonexistant
+  };
+  var config = getenv.multi(spec);
+  var expect = {
+    foo: 'default'
+  };
+  assert.deepEqual(expect, config);
+};
+
+tests['getenv.multi([string/typecast/throw]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_NONEXISTENT', undefined, 'string'] // throws when nonexistant
+  };
+  assert.throws(function() {
+    var config = getenv.multi(spec);
+  });
+};
+
+tests['getenv.multi([string/defaultval]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_STRING', 'default'] // throws when nonexistant
+  };
+  var config = getenv.multi(spec);
+  var expect = {
+    foo: process.env.TEST_GETENV_STRING
+  };
+  assert.deepEqual(expect, config);
+};
+
+tests['getenv.multi([string/defaultval/throw]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_NONEXISTENT', 'default'] // throws when nonexistant
+  };
+  var config = getenv.multi(spec);
+  var expect = {
+    foo: 'default'
+  };
+  assert.deepEqual(expect, config);
+};
+
+tests['getenv.multi([string/single]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_STRING'] // throws when nonexistant
+  };
+  var config = getenv.multi(spec);
+  var expect = {
+    foo: process.env.TEST_GETENV_STRING
+  };
+  assert.deepEqual(expect, config);
+};
+
+tests['getenv.multi([string/single/throw]) multiple env vars'] = function() {
+  var spec = {
+    foo: ['TEST_GETENV_NONEXISTENT'] // throws when nonexistant
+  };
+  assert.throws(function() {
+    var config = getenv.multi(spec);
+  });
+};
+
+
 Object.keys(tests).forEach(function(key) {
   console.log('Test: %s', key);
   tests[key]();