Support parsing simple values from env/argv strings (#273)

* simple parse, indexzero/nconf#72

* documentation for tryParse option

* Combine JSON parsing and simple parsing

README.md

@@ -191,6 +191,9 @@ Responsible for loading the values parsed from `process.argv` by `yargs` into th
 
 ### Env
 Responsible for loading the values parsed from `process.env` into the configuration hierarchy.
+Usually the env variables values are loaded into the configuration as strings.
+To ensure well-known strings ('false', 'true', 'null', 'undefined', '3', '5.1') and JSON values
+are properly parsed, the `parseValues` boolean option is available.
 
 ``` js
   //
@@ -225,7 +228,8 @@ Responsible for loading the values parsed from `process.env` into the configurat
     separator: '__',
     match: /^whatever_matches_this_will_be_whitelisted/
     whitelist: ['database__host', 'only', 'load', 'these', 'values', 'if', 'whatever_doesnt_match_but_is_whitelisted_gets_loaded_too'],
-    lowerCase: true
+    lowerCase: true,
+    parseValues: true
   });
   var dbHost = nconf.get('database:host');
 ```

lib/nconf/common.js

@@ -121,3 +121,23 @@ common.merge = function (objs) {
 common.capitalize = function (str) {
   return str && str[0].toUpperCase() + str.slice(1);
 };
+
+//
+// ### function parseValues (any)
+// #### @any {string} String to parse as native data-type or return as is
+// try to parse `any` as a native data-type
+//
+common.parseValues = function (value) {
+  var val = value;
+
+  try {
+    val = JSON.parse(value);
+  } catch (ignore) {
+    // Check for any other well-known strings that should be "parsed"
+    if (value === 'undefined'){
+      val = void 0;
+    }
+  }
+
+  return val;
+};

lib/nconf/stores/argv.js

@@ -6,6 +6,7 @@
  */
 
 var util = require('util'),
+    common = require('../common'),
     Memory = require('./memory').Memory;
 
 //
@@ -17,10 +18,12 @@ var util = require('util'),
 var Argv = exports.Argv = function (options, usage) {
   Memory.call(this, options);
 
+  options        = options || {};
   this.type     = 'argv';
   this.readOnly = true;
-  this.options  = options || false;
+  this.options  = options;
   this.usage    = usage;
+  this.parseValues = options.parseValues || false;
 };
 
 // Inherit from the Memory store
@@ -58,8 +61,14 @@ Argv.prototype.loadArgv = function () {
 
   this.readOnly = false;
   Object.keys(argv).forEach(function (key) {
-    if (typeof argv[key] !== 'undefined') {
-      self.set(key, argv[key]);
+    var val = argv[key];
+
+    if (typeof val !== 'undefined') {
+      if (self.parseValues) {
+        val = common.parseValues(val);
+      }
+
+      self.set(key, val);
     }
   });
 

lib/nconf/stores/env.js

@@ -83,20 +83,7 @@ Env.prototype.loadEnv = function () {
     var val = env[key];
 
     if (self.parseJson) {
-      try {
-        var ret = JSON.parse(val);
-
-        // apply JSON parsing only if its non-primitive types: JSON Object or Array
-        // avoid breaking backward-compatibility
-        if (typeof ret !== 'number' &&
-            typeof ret !== 'string' &&
-            typeof ret !== 'boolean') {
-          val = ret;
-        }
-
-      } catch (ignore) {
-        //ignore
-      }
+      val = common.parseValues(val);
     }
 
     if (self.separator) {

lib/nconf/stores/memory.js

@@ -23,6 +23,7 @@ var Memory = exports.Memory = function (options) {
   this.readOnly = false;
   this.loadFrom = options.loadFrom || null;
   this.logicalSeparator = options.logicalSeparator || ':';
+  this.parseValues = options.parseValues || false;
 
   if (this.loadFrom) {
     this.store = common.loadFilesSync(this.loadFrom);
@@ -100,6 +101,9 @@ Memory.prototype.set = function (key, value) {
 
   // Set the specified value in the nested JSON structure
   key = path.shift();
+  if (this.parseValues) {
+    value = common.parseValues.call(common, value);
+  }
   target[key] = value;
   return true;
 };

test/complete-test.js

@@ -161,7 +161,7 @@ vows.describe('nconf/multiple-stores').addBatch({
 }).addBatch({
   // Threw this in it's own batch to make sure it's run separately from the
   // sync check
-  "When using env with parseJson:true": {
+  "When using env with parseValues:true": {
     topic: function () {
       var that = this;
       helpers.cp(complete, completeTest, function () {
@@ -175,15 +175,7 @@ vows.describe('nconf/multiple-stores').addBatch({
           var val = process.env[key];
 
           try {
-            var ret = JSON.parse(val);
-
-            // apply JSON parsing only if its non-primitive types: JSON Object or Array
-            // avoid breaking backward-compatibility
-            if (typeof ret !== 'number' &&
-                typeof ret !== 'string' &&
-                typeof ret !== 'boolean') {
-              val = ret;
-            }
+            val = JSON.parse(val);
           } catch (err) {}
 
           assert.deepEqual(nconf.get(key), val);

test/provider-test.js

@@ -47,7 +47,42 @@ vows.describe('nconf/provider').addBatch({
       "when 'env' is true": helpers.assertSystemConf({
         script: path.join(fixturesDir, 'scripts', 'provider-env.js'),
         env: { SOMETHING: 'foobar' }
-      })
+      }),
+      "when 'env' is true and 'parseValues' option is true": {
+        topic: function() {
+          var env = {
+            SOMETHING: 'foobar',
+            SOMEBOOL: 'true',
+            SOMENULL: 'null',
+            SOMEUNDEF: 'undefined',
+            SOMEINT: '3600',
+            SOMEFLOAT: '0.5',
+            SOMEBAD: '5.1a'
+          };
+          var oenv = {};
+          Object.keys(env).forEach(function (key) {
+              if (process.env[key]) oenv[key] = process.env[key];
+              process.env[key] = env[key];
+          });
+          var provider = new nconf.Provider().use('env', {parseValues: true});
+          Object.keys(env).forEach(function (key) {
+              delete process.env[key];
+              if (oenv[key]) process.env[key] = oenv[key];
+          });
+          return provider;
+        },
+        "should respond with parsed values": function (provider) {
+
+          assert.equal(provider.get('SOMETHING'), 'foobar');
+          assert.strictEqual(provider.get('SOMEBOOL'), true);
+          assert.notEqual(provider.get('SOMEBOOL'), 'true');
+          assert.strictEqual(provider.get('SOMENULL'), null);
+          assert.strictEqual(provider.get('SOMEUNDEF'), undefined);
+          assert.strictEqual(provider.get('SOMEINT'), 3600);
+          assert.strictEqual(provider.get('SOMEFLOAT'), .5);
+          assert.strictEqual(provider.get('SOMEBAD'), '5.1a');
+        }
+      }
     },
     "the default nconf provider": {
       "when 'argv' is set to true": helpers.assertSystemConf({

test/stores/argv-test.js

@@ -16,7 +16,7 @@ vows.describe('nconf/stores/argv').addBatch({
     "should have the correct methods defined": function (argv) {
       assert.isFunction(argv.loadSync);
       assert.isFunction(argv.loadArgv);
-      assert.isFalse(argv.options);
+      assert.deepEqual(argv.options, {});
     }
   }
 }).export(module);