Improve detection of ChefFS-based commands in `knife rehash`ssd/rehash-cheffs

ChefFS-based commands have a superclass (Chef::ChefFS::Knife) which
defines its own inherited method that calls super. This breaks our
detection of where the subcommand is defined since the file with
the definition is no longer at the top of the call stack.

This commit special-cases subclasses with a superclass of
Chef::ChefFS::Knife to account for this.

Fixes #4089

3 files changed, 23 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 17608b32f8..2d434b3c28 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -48,6 +48,7 @@
 * [pr#3597](https://github.com/chef/chef/pull/3597) print STDOUT from the powershell_script
 * [pr#4091](https://github.com/chef/chef/pull/4091) Allow downloading of root_files in a chef repository
 * [pr#4112](https://github.com/chef/chef/pull/4112) Update knife bootstrap command to honor --no-color flag in chef-client run that is part of the bootstrap process.
+* [pr#4090](https://github.com/chef/chef/pull/4090) Improve detection of ChefFS-based commands in `knife rehash`
 
 ## 12.5.1
 
diff --git a/lib/chef/knife.rb b/lib/chef/knife.rb
index 46e968827e..fed2ad4cfa 100644
--- a/lib/chef/knife.rb
+++ b/lib/chef/knife.rb
@@ -87,7 +87,16 @@ class Chef
     def self.inherited(subclass)
       unless subclass.unnamed?
         subcommands[subclass.snake_case_name] = subclass
-        subcommand_files[subclass.snake_case_name] += [caller[0].split(/:\d+/).first]
+        subcommand_files[subclass.snake_case_name] +=
+          if subclass.superclass.to_s == "Chef::ChefFS::Knife"
+            # ChefFS-based commands have a superclass that defines an
+            # inhereited method which calls super. This means that the
+            # top of the call stack is not the class definition for
+            # our subcommand.  Try the second entry in the call stack.
+            [path_from_caller(caller[1])]
+          else
+            [path_from_caller(caller[0])]
+          end
       end
     end
 
@@ -221,6 +230,10 @@ class Chef
 
     OFFICIAL_PLUGINS = %w[ec2 rackspace windows openstack terremark bluebox]
 
+    def self.path_from_caller(caller_line)
+      caller_line.split(/:\d+/).first
+    end
+
     # :nodoc:
     # Error out and print usage. probably because the arguments given by the
     # user could not be resolved to a subcommand.
diff --git a/spec/unit/knife_spec.rb b/spec/unit/knife_spec.rb
index 022256f370..9e76ec59c4 100644
--- a/spec/unit/knife_spec.rb
+++ b/spec/unit/knife_spec.rb
@@ -117,6 +117,14 @@ describe Chef::Knife do
       expect(Chef::Knife.subcommands["super_awesome_command"]).to eq(SuperAwesomeCommand)
     end
 
+    it "records the location of ChefFS-based commands correctly" do
+      class AwesomeCheffsCommand < Chef::ChefFS::Knife
+      end
+
+      Chef::Knife.load_commands
+      expect(Chef::Knife.subcommand_files["awesome_cheffs_command"]).to eq([__FILE__])
+    end
+
     it "guesses a category from a given ARGV" do
       Chef::Knife.subcommands_by_category["cookbook"] << :cookbook
       Chef::Knife.subcommands_by_category["cookbook site"] << :cookbook_site