if cypress.env.debug is set, log command execution thru server

Author: flotwig

packages/driver/src/cypress/cy.coffee

@@ -60,7 +60,7 @@ setTopOnError = (cy) ->
   if curCy
     curCy = cy
     return
-  
+
   curCy = cy
 
   onTopError = ->
@@ -76,7 +76,7 @@ setTopOnError = (cy) ->
     configurable: false
     enumerable: true
   })
-  
+
 
 create = (specWindow, Cypress, Cookies, state, config, log) ->
   stopped = false
@@ -419,7 +419,13 @@ create = (specWindow, Cypress, Cookies, state, config, log) ->
 
       Cypress.action("cy:command:start", command)
 
-      runCommand(command)
+
+      new Promise (resolve) ->
+        if (a = Cypress.env('DEBUG'))
+          return resolve(Cypress.backend('debug:command', command))
+        resolve()
+      .then ->
+        runCommand(command)
       .then ->
         ## each successful command invocation should
         ## always reset the timeout for the current runnable
@@ -1133,7 +1139,7 @@ create = (specWindow, Cypress, Cookies, state, config, log) ->
           args: obj
         })
     })
-  
+
   setTopOnError(cy)
 
   ## make cy global in the specWindow

packages/server/lib/socket.coffee

@@ -288,7 +288,8 @@ class Socket
         ## cb is always the last argument
         cb = args.pop()
 
-        debug("backend:request %o", { eventName, args })
+        if eventName isnt 'debug:command'
+          debug("backend:request %o", { eventName, args })
 
         backendRequest = ->
           switch eventName
@@ -310,6 +311,8 @@ class Socket
               files.readFile(config.projectRoot, args[0], args[1])
             when "write:file"
               files.writeFile(config.projectRoot, args[0], args[1], args[2])
+            when "debug:command"
+              debug('command ran in driver: cy.%s %o', args[0].name, _.pick(args[0], 'args'))
             when "exec"
               exec.run(config.projectRoot, args[0])
             when "task"