Make --restart-tries restart forever with negative value

Closes #263

README.md

@@ -169,9 +169,10 @@ Killing other processes
                          code                                          [boolean]
 
 Restarting
-  --restart-tries  How many times a process that died should restart.
+      --restart-tries  How many times a process that died should restart.
+                       Negative numbers will make the process restart forever.
                                                            [number] [default: 0]
-  --restart-after  Delay time to respawn the process, in milliseconds.
+      --restart-after  Delay time to respawn the process, in milliseconds.
                                                            [number] [default: 0]
 
 Options:

bin/concurrently.js

@@ -107,7 +107,9 @@ const args = yargs
 
         // Restarting
         'restart-tries': {
-            describe: 'How many times a process that died should restart.',
+            describe:
+                'How many times a process that died should restart.\n' +
+                'Negative numbers will make the process restart forever.',
             default: defaults.restartTries,
             type: 'number'
         },

src/flow-control/restart-process.js

@@ -7,6 +7,7 @@ module.exports = class RestartProcess {
     constructor({ delay, tries, logger, scheduler }) {
         this.delay = +delay || defaults.restartDelay;
         this.tries = +tries || defaults.restartTries;
+        this.tries = this.tries < 0 ? Infinity : this.tries;
         this.logger = logger;
         this.scheduler = scheduler;
     }

src/flow-control/restart-process.spec.js

@@ -69,6 +69,8 @@ it('restarts processes up to tries', () => {
     expect(commands[0].start).toHaveBeenCalledTimes(2);
 });
 
+it.todo('restart processes forever, if tries is negative');
+
 it('restarts processes until they succeed', () => {
     controller.handle(commands);