Update hostname option documentation

Author: EdgeJ

doc/optionsref.md

@@ -9,7 +9,8 @@
 
 ```
 Usage: octocatalog-diff [command line options]
-    -n, --hostname HOSTNAME          Use PuppetDB facts from last run of hostname
+    -n HOSTNAME1[,HOSTNAME2[,...]],  Use PuppetDB facts from last run of a hostname or a comma separated list of multiple hostnames
+        --hostname
         --basedir DIRNAME            Use an alternate base directory (git checkout of puppet repository)
     -f, --from FROM_BRANCH           Branch you are coming from
     -t, --to TO_BRANCH               Branch you are going to
@@ -856,14 +857,17 @@ Puppet control repo template, the value of this should be 'hieradata', which is
 
   <tr>
     <td valign=top>
-      <pre><code>-n HOSTNAME
---hostname HOSTNAME</code></pre>
+      <pre><code>-n HOSTNAME1[,HOSTNAME2[,...]]
+--hostname HOSTNAME1[,HOSTNAME2[,...]]</code></pre>
     </td>
     <td valign=top>
-      Use PuppetDB facts from last run of hostname
+      Use PuppetDB facts from last run of a hostname or a comma separated list of multiple hostnames
     </td>
     <td valign=top>
-      Set hostname, which is used to look up facts in PuppetDB, and in the header of diff display. (<a href="../lib/octocatalog-diff/cli/options/hostname.rb">hostname.rb</a>)
+      Set hostname, which is used to look up facts in PuppetDB, and in the header of diff display.
+This option can recieve a single hostname, or a comma separated list of
+multiple hostnames, which are split into an Array. Multiple hostnames do not
+work with the `catalog-only` or `bootstrap-then-exit` options. (<a href="../lib/octocatalog-diff/cli/options/hostname.rb">hostname.rb</a>)
     </td>
   </tr>
 

lib/octocatalog-diff/cli/options.rb

@@ -11,7 +11,7 @@ class Cli
     # This class contains the option parser. 'parse_options' is the external entry point.
     class Options
       # The usage banner.
-      BANNER = 'Usage: catalog-diff -n <hostname> [-f <from environment>] [-t <to environment>]'.freeze
+      BANNER = 'Usage: catalog-diff -n <hostname>[,<hostname>...] [-f <from environment>] [-t <to environment>]'.freeze
 
       # An error class specifically for passing information to the document build task.
       class DocBuildError < RuntimeError; end

lib/octocatalog-diff/cli/options/hostname.rb

@@ -1,14 +1,21 @@
 # frozen_string_literal: true
 
 # Set hostname, which is used to look up facts in PuppetDB, and in the header of diff display.
+# This option can recieve a single hostname, or a comma separated list of
+# multiple hostnames, which are split into an Array. Multiple hostnames do not
+# work with the `catalog-only` or `bootstrap-then-exit` options.
 # @param parser [OptionParser object] The OptionParser argument
 # @param options [Hash] Options hash being constructed; this is modified in this method.
 
 OctocatalogDiff::Cli::Options::Option.newoption(:hostname) do
   has_weight 1
 
   def parse(parser, options)
-    parser.on('--hostname HOSTNAME', '-n', 'Use PuppetDB facts from last run of hostname') do |hostname|
+    parser.on(
+      '--hostname HOSTNAME1[,HOSTNAME2[,...]]',
+      '-n',
+      'Use PuppetDB facts from last run of a hostname or a comma separated list of multiple hostnames'
+    ) do |hostname|
       options[:node] = if hostname.include?(',')
         hostname.split(',')
       else