Force requiring properties

All required properties are now required for all actions by default
even if the action does not reference the property.

In order to only make the property required for a subset of the
actions, specify them as an array of symbols to the required
options on the property.

```
property :whatever, String, required: %i{start stop}

action :start do
end

action :stop do
end

action :enable do
end

action :disable do
end
```

That property will be required for start+stop but not for
enable+disable.

There's an unaddressed edge case here where if you reference the
property in an action which was not specified that it will also
fail validation.  That is correct behavior.  We should probably
dig into how to warn the user that they must either remove the
reference to the property from that action or else to add the
action to the list of required actions on the property.

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

3 files changed, 41 insertions, 4 deletions

diff --git a/lib/chef/property.rb b/lib/chef/property.rb
index eaf1a66e86..d65545c138 100644
--- a/lib/chef/property.rb
+++ b/lib/chef/property.rb
@@ -303,8 +303,12 @@ class Chef
     #
     # @return [Boolean]
     #
-    def required?
-      options[:required]
+    def required?(action = nil)
+      if !action.nil? && options[:required].is_a?(Array)
+        options[:required].include?(action)
+      else
+        !!options[:required]
+      end
     end
 
     #
diff --git a/lib/chef/provider.rb b/lib/chef/provider.rb
index 40bd5a48a1..947a890806 100644
--- a/lib/chef/provider.rb
+++ b/lib/chef/provider.rb
@@ -152,6 +152,7 @@ class Chef
       new_resource.cookbook_name
     end
 
+    # hook that subclasses can use to do lazy validation for where properties aren't flexibile enough
     def check_resource_semantics!; end
 
     # a simple placeholder method that will be called / raise if a resource tries to
@@ -181,12 +182,20 @@ class Chef
       run_context.events
     end
 
+    def validate_required_properties!
+      # all we do is run through all the required properties for this action and vivify them
+      new_resource.class.properties.each { |name, property| property.required?(action) && property.get(new_resource) }
+    end
+
     def run_action(action = nil)
       @action = action unless action.nil?
 
-      # @todo it would be preferable to get the action to be executed in the constructor...
+      # hook that subclasses can use to do lazy validation for where properties aren't flexibile enough
       check_resource_semantics!
 
+      # force the validation of required properties
+      validate_required_properties!
+
       # user-defined LWRPs may include unsafe load_current_resource methods that cannot be run in whyrun mode
       if whyrun_mode? && !whyrun_supported?
         events.resource_current_state_load_bypassed(@new_resource, @action, @current_resource)
diff --git a/spec/unit/property/validation_spec.rb b/spec/unit/property/validation_spec.rb
index dab2be8000..c8daee1580 100644
--- a/spec/unit/property/validation_spec.rb
+++ b/spec/unit/property/validation_spec.rb
@@ -45,11 +45,22 @@ describe "Chef::Resource.property validation" do
       def self.blah
         "class#{Namer.next_index}"
       end
+
+      action :doit do
+        # this needs to not reference any properties
+      end
+
+      action :doit2 do
+        # this needs to not reference any properties
+      end
     end
   end
 
+  let(:node) { Chef::Node.new }
+  let(:events) { Chef::EventDispatch::Dispatcher.new }
+  let(:run_context) { Chef::RunContext.new(node, {}, events) }
   let(:resource) do
-    resource_class.new("blah")
+    resource_class.new("blah", run_context)
   end
 
   def self.english_join(values)
@@ -576,6 +587,19 @@ describe "Chef::Resource.property validation" do
       it "value nil emits a validation failed error because it must have a value" do
         expect { resource.x nil }.to raise_error Chef::Exceptions::ValidationFailed
       end
+      it "fails if it is not specified, on running the action, even if it is not referenced" do
+        expect { resource.run_action(:doit) }.to raise_error Chef::Exceptions::ValidationFailed
+      end
+    end
+
+    with_property ":x, required: %i{doit}" do
+      it "fails if it is not specified, on running the doit action, even if it is not referenced" do
+        expect { resource.run_action(:doit) }.to raise_error Chef::Exceptions::ValidationFailed
+      end
+
+      it "does not fail if it is not specified, on running the doit2 action" do
+        expect { resource.run_action(:doit2) }.not_to raise_error
+      end
     end
 
     with_property ":x, String, required: true" do