feat(validation): Add .skipValidation() method (#471)

README.md

@@ -1142,6 +1142,7 @@ Valid `opt` keys include:
 - `normalize`: boolean, apply `path.normalize()` to the option, see [`normalize()`](#normalize)
 - `number`: boolean, interpret option as a number, [`number()`](#number)
 - `requiresArg`: boolean, require the option be specified with a value, see [`requiresArg()`](#requiresArg)
+- `skipValidation`: boolean, skips validation if the option is present, see [`skipValidation()`](#skipValidation)
 - `string`: boolean, interpret option as a string, see [`string()`](#string)
 - `type`: one of the following strings
     - `'array'`: synonymous for `array: true`, see [`array()`](#array)
@@ -1282,6 +1283,12 @@ Missing argument value: f
 Specify --help for available options
 ```
 
+<a name="skipValidation"></a>.skipValidation(key)
+-----------------
+
+Specifies either a single option key (string), or an array of options.
+If any of the options is present, yargs validation is skipped.
+
 .strict()
 ---------
 

test/yargs.js

@@ -232,6 +232,7 @@ describe('yargs dsl tests', function () {
         defaultDescription: {},
         choices: {},
         requiresArg: [],
+        skipValidation: [],
         count: [],
         normalize: [],
         number: [],
@@ -886,6 +887,43 @@ describe('yargs dsl tests', function () {
       argv.dotNotation.should.equal(false)
     })
   })
+
+  describe('skipValidation', function () {
+    it('skips validation if an option with skipValidation is present', function () {
+      var argv = yargs(['--koala', '--skip'])
+          .demand(1)
+          .fail(function (msg) {
+            expect.fail()
+          })
+          .skipValidation(['skip', 'reallySkip'])
+          .argv
+      argv.koala.should.equal(true)
+    })
+
+    it('does not skip validation if no option with skipValidation is present', function (done) {
+      var argv = yargs(['--koala'])
+          .demand(1)
+          .fail(function (msg) {
+            return done()
+          })
+          .skipValidation(['skip', 'reallySkip'])
+          .argv
+      argv.koala.should.equal(true)
+    })
+
+    it('allows key to be specified with option shorthand', function () {
+      var argv = yargs(['--koala', '--skip'])
+          .demand(1)
+          .fail(function (msg) {
+            expect.fail()
+          })
+          .option('skip', {
+            skipValidation: true
+          })
+          .argv
+      argv.koala.should.equal(true)
+    })
+  })
 })
 
 describe('yargs context', function () {

yargs.js

@@ -92,7 +92,7 @@ function Yargs (processArgs, cwd, parentRequire) {
     groups = {}
 
     var arrayOptions = [
-      'array', 'boolean', 'string', 'requiresArg',
+      'array', 'boolean', 'string', 'requiresArg', 'skipValidation',
       'count', 'normalize', 'number'
     ]
 
@@ -279,6 +279,11 @@ function Yargs (processArgs, cwd, parentRequire) {
     return self
   }
 
+  self.skipValidation = function (skipValidations) {
+    options.skipValidation.push.apply(options.skipValidation, [].concat(skipValidations))
+    return self
+  }
+
   self.implies = function (key, value) {
     validation.implies(key, value)
     return self
@@ -390,6 +395,8 @@ function Yargs (processArgs, cwd, parentRequire) {
         self.count(key)
       } if (opt.defaultDescription) {
         options.defaultDescription[key] = opt.defaultDescription
+      } if (opt.skipValidation) {
+        self.skipValidation(key)
       }
 
       var desc = opt.describe || opt.description || opt.desc
@@ -657,26 +664,35 @@ function Yargs (processArgs, cwd, parentRequire) {
       return
     }
 
-    var helpOrVersion = false
+    var skipValidation = false
+
+    // Handle 'help' and 'version' options
     Object.keys(argv).forEach(function (key) {
       if (key === helpOpt && argv[key]) {
-        helpOrVersion = true
+        skipValidation = true
         self.showHelp('log')
         if (exitProcess) {
           process.exit(0)
         }
       } else if (key === versionOpt && argv[key]) {
-        helpOrVersion = true
+        skipValidation = true
         usage.showVersion()
         if (exitProcess) {
           process.exit(0)
         }
       }
     })
 
+    // Check if any of the options to skip validation were provided
+    if (!skipValidation && options.skipValidation.length > 0) {
+      skipValidation = Object.keys(argv).some(function (key) {
+        return options.skipValidation.indexOf(key) >= 0
+      })
+    }
+
     // If the help or version options where used and exitProcess is false,
-    // we won't run validations
-    if (!helpOrVersion) {
+    // or if explicitly skipped, we won't run validations
+    if (!skipValidation) {
       if (parsed.error) throw parsed.error
 
       // if we're executed via bash completion, don't