1 files changed, 19 insertions, 6 deletions

diff --git a/node_modules/yargs/lib/command.js b/node_modules/yargs/lib/command.js
index 5ac848e21..65322dbbd 100644
--- a/node_modules/yargs/lib/command.js
+++ b/node_modules/yargs/lib/command.js
@@ -11,27 +11,26 @@ const DEFAULT_MARKER = /(^\*)|(^\$0)/
 // arguments.
 module.exports = function command (yargs, usage, validation) {
   const self = {}
-
   let handlers = {}
   let aliasMap = {}
   let defaultCommand
-  self.addHandler = function addHandler (cmd, description, builder, handler) {
+  self.addHandler = function addHandler (cmd, description, builder, handler, middlewares) {
     let aliases = []
     handler = handler || (() => {})
-
+    middlewares = middlewares || []
     if (Array.isArray(cmd)) {
       aliases = cmd.slice(1)
       cmd = cmd[0]
     } else if (typeof cmd === 'object') {
       let command = (Array.isArray(cmd.command) || typeof cmd.command === 'string') ? cmd.command : moduleName(cmd)
       if (cmd.aliases) command = [].concat(command).concat(cmd.aliases)
-      self.addHandler(command, extractDesc(cmd), cmd.builder, cmd.handler)
+      self.addHandler(command, extractDesc(cmd), cmd.builder, cmd.handler, cmd.middlewares)
       return
     }
 
     // allow a module to be provided instead of separate builder and handler
     if (typeof builder === 'object' && builder.builder && typeof builder.handler === 'function') {
-      self.addHandler([cmd].concat(aliases), description, builder.builder, builder.handler)
+      self.addHandler([cmd].concat(aliases), description, builder.builder, builder.handler, builder.middlewares)
       return
     }
 
@@ -50,6 +49,7 @@ module.exports = function command (yargs, usage, validation) {
       }
       return true
     })
+
     // standardize on $0 for default command.
     if (parsedAliases.length === 0 && isDefault) parsedAliases.push('$0')
 
@@ -74,6 +74,7 @@ module.exports = function command (yargs, usage, validation) {
       description: description,
       handler,
       builder: builder || {},
+      middlewares: middlewares || [],
       demanded: parsedCommand.demanded,
       optional: parsedCommand.optional
     }
@@ -225,7 +226,19 @@ module.exports = function command (yargs, usage, validation) {
 
     if (commandHandler.handler && !yargs._hasOutput()) {
       yargs._setHasOutput()
-      commandHandler.handler(innerArgv)
+      if (commandHandler.middlewares.length > 0) {
+        const middlewareArgs = commandHandler.middlewares.reduce(function (initialObj, middleware) {
+          return Object.assign(initialObj, middleware(innerArgv))
+        }, {})
+        Object.assign(innerArgv, middlewareArgs)
+      }
+      const handlerResult = commandHandler.handler(innerArgv)
+      if (handlerResult && typeof handlerResult.then === 'function') {
+        handlerResult.then(
+          null,
+          (error) => yargs.getUsageInstance().fail(null, error)
+        )
+      }
     }
 
     if (command) {