feat(argv): handle nconf options w/ external yargs

README.md

@@ -240,10 +240,10 @@ If the return value is falsey, the entry will be dropped from the store, otherwi
   });
 ```
 
-It's also possible to pass a configured yargs instance
+It's also possible to pass a configured yargs instance and also include relevant nconf options.
 
 ``` js
-  nconf.argv(require('yargs')
+  let yargs = require('yargs')
     .version('1.2.3')
     .usage('My usage definition')
     .strict()
@@ -254,7 +254,11 @@ It's also possible to pass a configured yargs instance
         demand: true,
         default: 'some-value'
       }
-    }));
+    });
+
+  nconf.argv(yargs, {
+    parseValues: true
+  });
 ```
 
 ### Env

lib/nconf/stores/argv.js

@@ -18,26 +18,39 @@ var util = require('util'),
 var Argv = exports.Argv = function (options, usage) {
   Memory.call(this, options);
 
-  options        = options || {};
+  this.isYargsExternal = false;
+
+  options = options || {};
+
+  // Consistent handling when a yargs instance is passed in
+  if (isYargs(options)) {
+    this.yargs = this.options = options;
+    this.isYargsExternal = true;
+
+    this._internalOptions = typeof usage === 'object' ? usage : {};
+  } else {
+    this.yargs = require('yargs');
+    this.options = this._internalOptions = options;
+  }
+
   this.type     = 'argv';
   this.readOnly = true;
-  this.options  = options;
   this.usage    = usage;
-  if(typeof options.parseValues === 'boolean') {
-      this.parseValues = options.parseValues;
-      delete options.parseValues;
+  if(typeof this._internalOptions.parseValues === 'boolean') {
+      this.parseValues = this._internalOptions.parseValues;
+      delete this._internalOptions.parseValues;
   } else {
       this.parseValues = false;
   }
-  if (typeof options.transform === 'function') {
-      this.transform = options.transform;
-      delete options.transform;
+  if (typeof this._internalOptions.transform === 'function') {
+      this.transform = this._internalOptions.transform;
+      delete this._internalOptions.transform;
   } else {
       this.transform = false;
   }
-  if (typeof options.separator === 'string' || options.separator instanceof RegExp) {
-    this.separator = options.separator;
-    delete options.separator;
+  if (typeof this._internalOptions.separator === 'string' || this._internalOptions.separator instanceof RegExp) {
+    this.separator = this._internalOptions.separator;
+    delete this._internalOptions.separator;
   } else {
     this.separator = '';
   }
@@ -61,14 +74,17 @@ Argv.prototype.loadSync = function () {
 // into this instance.
 //
 Argv.prototype.loadArgv = function () {
-  var self = this,
-      yargs, argv;
-
-  yargs = isYargs(this.options) ?
-    this.options :
-    typeof this.options === 'object' ?
-      require('yargs')(process.argv.slice(2)).options(this.options) :
-      require('yargs')(process.argv.slice(2));
+  var self = this;
+  var yargs = this.yargs;
+  var argv;
+
+  if (!this.isYargsExternal) {
+    if (typeof this._internalOptions === 'object') {
+      yargs = this.yargs(process.argv.slice(2)).options(this._internalOptions);
+    } else {
+      yargs = this.yargs(process.argv.slice(2));
+    }
+  }
 
   if (typeof this.usage === 'string') { yargs.usage(this.usage) }
 

package.json

@@ -22,7 +22,7 @@
     "async": "^3.0.0",
     "ini": "^2.0.0",
     "secure-keys": "^1.0.0",
-    "yargs": "^16.1.1"
+    "yargs": "^17.4.1"
   },
   "devDependencies": {
     "coveralls": "^3.1.0",

test/stores/argv-test.js

@@ -35,6 +35,26 @@ vows.describe('nconf/stores/argv').addBatch({
         assert.equal(argv.get('v'), 'false');
       }
     },
+    "can be created with a custom yargs with nconf options":{
+      topic: function(){
+        var yargsInstance = yargs(['--help', 'foo']).alias('v', 'verbose').default('v', 'false').version(false).help(false).usage(false);
+        return [yargsInstance, new nconf.Argv(yargsInstance, {
+          parseValues: true,
+        })];
+      },
+      "and can give access to them": function (argv) {
+        var yargsInstance = argv[0];
+        argv = argv[1]
+        assert.equal(argv.options, yargsInstance)
+      },
+      "values are the one from the custom yargv, but parsed": function (argv) {
+        argv = argv[1]
+        argv.loadSync()
+        assert.equal(argv.get('verbose'), false);
+        assert.equal(argv.get('v'), false);
+        assert.equal(argv.get('help'), 'foo');
+      }
+    },
     "can be created with a nconf yargs":{
       topic: function(){
         var options = {verbose: {alias: 'v', default: 'false'}};