pass sessionId arg when calling deleteSession. Make error message for NewCommandTimeout more helpful

lib/commands/session.js

@@ -54,7 +54,7 @@ commands.getSession = async function () {
   return this.caps;
 };
 
-commands.deleteSession = async function () {
+commands.deleteSession = async function (/* sessionId */) {
   this.clearNewCommandTimeout();
   this.sessionId = null;
 };

lib/commands/timeout.js

@@ -24,7 +24,7 @@ helpers.clearNewCommandTimeout = function () {
   }
 };
 
-helpers.startNewCommandTimeout = function (cmd) {
+helpers.startNewCommandTimeout = function () {
   // make sure there are no rogue timeouts
   this.clearNewCommandTimeout();
 
@@ -36,7 +36,11 @@ helpers.startNewCommandTimeout = function (cmd) {
     .then(async () => {
       log.warn(`Shutting down because we waited ` +
                `${this.newCommandTimeoutMs / 1000} seconds for a command`);
-      await this.startUnexpectedShutdown(new Error(`Command ${cmd} timed out!`));
+      let errorMessage = `New Command Timeout of ` +
+               `${this.newCommandTimeoutMs / 1000} seconds ` +
+               `expired. Try customizing the timeout using the ` +
+               `'newCommandTimeout' desired capability`;
+      await this.startUnexpectedShutdown(new Error(errorMessage));
     })
     .catch(B.CancellationError, (/*err*/) => {
       // ignore

lib/driver.js

@@ -175,7 +175,7 @@ class BaseDriver extends MobileJsonWireProtocol {
     // intentionally
     if (cmd !== 'deleteSession') {
       // reseting existing timeout
-      this.startNewCommandTimeout(cmd);
+      this.startNewCommandTimeout();
     }
 
     return res;
@@ -185,7 +185,7 @@ class BaseDriver extends MobileJsonWireProtocol {
     this.unexpectedShutdownDeferred.reject(err); // allow others to listen for this
     this.curCommandCancellable.cancel(err);
     this.shutdownUnexpectedly = true;
-    await this.deleteSession();
+    await this.deleteSession(this.sessionId);
     this.shutdownUnexpectedly = false;
   }
 
@@ -219,7 +219,7 @@ class BaseDriver extends MobileJsonWireProtocol {
     this.resetOnUnexpectedShutdown = () => {};
 
     try {
-      await this.deleteSession();
+      await this.deleteSession(this.sessionId);
       log.debug('Restarting app');
       await this.createSession(this.caps);
     } finally {