Rework Resource#action to match the 12.3 API.

This means it always coerces to an Array. Also ensures that
Resource#action= goes through the same validation.

Fixes #3604.

2 files changed, 44 insertions, 8 deletions

diff --git a/lib/chef/resource.rb b/lib/chef/resource.rb
index 8d2532dac4..353eaddfa2 100644
--- a/lib/chef/resource.rb
+++ b/lib/chef/resource.rb
@@ -169,26 +169,24 @@ class Chef
     # @param arg [Array[Symbol], Symbol] A list of actions (e.g. `:create`)
     # @return [Array[Symbol]] the list of actions.
     #
-    attr_accessor :action
     def action(arg=nil)
       if arg
-        if arg.is_a?(Array)
-          arg = arg.map { |a| a.to_sym }
-        else
-          arg = arg.to_sym
-        end
-        Array(arg).each do |action|
+        arg = Array(arg).map(&:to_sym)
+        arg.each do |action|
           validate(
             { action: action },
             { action: { kind_of: Symbol, equal_to: allowed_actions } }
           )
         end
-        self.action = arg
+        @action = arg
       else
         @action
       end
     end
 
+    # Alias for normal assigment syntax.
+    alias_method :action=, :action
+
     #
     # Sets up a notification that will run a particular action on another resource
     # if and when *this* resource is updated by an action.
diff --git a/spec/unit/resource_spec.rb b/spec/unit/resource_spec.rb
index 8b0baff921..44fe1e90a3 100644
--- a/spec/unit/resource_spec.rb
+++ b/spec/unit/resource_spec.rb
@@ -977,4 +977,42 @@ describe Chef::Resource do
     end
 
   end
+
+  describe "#action" do
+    let(:resource_class) do
+      Class.new(described_class) do
+        allowed_actions(%i{one two})
+      end
+    end
+    let(:resource) { resource_class.new('test', nil) }
+    subject { resource.action }
+
+    context "with a symbol action" do
+      before { resource.action(:one) }
+      it { is_expected.to eq [:one] }
+    end
+
+    context "with a string action" do
+      before { resource.action('two') }
+      it { is_expected.to eq [:two] }
+    end
+
+    context "with an array action" do
+      before { resource.action([:two, :one]) }
+      it { is_expected.to eq [:two, :one] }
+    end
+
+    context "with an assignment" do
+      before { resource.action = :one }
+      it { is_expected.to eq [:one] }
+    end
+
+    context "with an invalid action" do
+      it { expect { resource.action(:three) }.to raise_error Chef::Exceptions::ValidationFailed }
+    end
+
+    context "with an invalid assignment action" do
+      it { expect { resource.action = :three }.to raise_error Chef::Exceptions::ValidationFailed }
+    end
+  end
 end