feat: remove setPlaceholderKeys (#1105)

BREAKING CHANGE: Options absent from `argv` (not set via CLI argument) are now absent from the parsed result object rather tahn being set with `undefined`

test/yargs.js

@@ -40,12 +40,12 @@ describe('yargs dsl tests', () => {
     argv.cat.should.eql(33)
   })
 
-  it('populates argv with placeholder keys for all options', () => {
+  it('do not populates argv with placeholder keys for unset options', () => {
     const argv = yargs([])
       .option('cool', {})
       .parse()
 
-    Object.keys(argv).should.include('cool')
+    Object.keys(argv).should.not.include('cool')
   })
 
   it('accepts an object for implies', () => {
@@ -70,7 +70,6 @@ describe('yargs dsl tests', () => {
     )
 
     r.errors[0].should.match(/really cool key/)
-    r.result.should.have.property('x')
     r.result.should.not.have.property('[object Object]')
   })
 

yargs.js

@@ -1053,7 +1053,6 @@ function Yargs (processArgs, cwd, parentRequire) {
           for (let i = (commandIndex || 0), cmd; argv._[i] !== undefined; i++) {
             cmd = String(argv._[i])
             if (~handlerKeys.indexOf(cmd) && cmd !== completionCommand) {
-              setPlaceholderKeys(argv)
               // commands are executed using a recursive algorithm that executes
               // the deepest command first; we keep track of the position in the
               // argv._ array that is currently being executed.
@@ -1066,7 +1065,6 @@ function Yargs (processArgs, cwd, parentRequire) {
 
           // run the default command, if defined
           if (command.hasDefaultCommand() && !skipDefaultCommand) {
-            setPlaceholderKeys(argv)
             return command.runCommand(null, self, parsed)
           }
 
@@ -1084,7 +1082,6 @@ function Yargs (processArgs, cwd, parentRequire) {
           self.exit(0)
         }
       } else if (command.hasDefaultCommand() && !skipDefaultCommand) {
-        setPlaceholderKeys(argv)
         return command.runCommand(null, self, parsed)
       }
 
@@ -1103,7 +1100,7 @@ function Yargs (processArgs, cwd, parentRequire) {
 
           self.exit(0)
         })
-        return setPlaceholderKeys(argv)
+        return argv
       }
 
       // Handle 'help' and 'version' options
@@ -1147,7 +1144,7 @@ function Yargs (processArgs, cwd, parentRequire) {
       else throw err
     }
 
-    return setPlaceholderKeys(argv)
+    return argv
   }
 
   self._runValidation = function runValidation (argv, aliases, positionalMap, parseErrors) {
@@ -1173,16 +1170,6 @@ function Yargs (processArgs, cwd, parentRequire) {
     }
   }
 
-  function setPlaceholderKeys (argv) {
-    Object.keys(options.key).forEach((key) => {
-      // don't set placeholder keys for dot
-      // notation options 'foo.bar'.
-      if (~key.indexOf('.')) return
-      if (typeof argv[key] === 'undefined') argv[key] = undefined
-    })
-    return argv
-  }
-
   // an app should almost always have --version and --help,
   // if you *really* want to disable this use .help(false)/.version(false).
   self.help()