(PUP-11937) Skip autorequire if exec's param is deferred and lazily evaluated

If an exec's 'command' parameter is deferred and lazily evaluated, then we can't
autorequire the file that the command will execute. This is because we won't
know what the command will be until the exec is evaluated. But that means it's
already too late to add a relationship from the file resource to the exec
resource. In this situation an explicit relationship must be added to ensure
the file resource is evaluated before the exec. The same is true for the
'onlyif' and 'unless' exec parameters.

Author: joshcooper

lib/puppet/type/exec.rb

@@ -592,13 +592,17 @@ def check(value)
       cmd = self[:command]
       cmd = cmd[0] if cmd.is_a? Array
 
-      cmd.scan(file_regex) { |str|
-        reqs << str
-      }
+      if cmd.is_a?(Puppet::Pops::Evaluator::DeferredValue)
+        self.debug("The 'command' parameter is deferred and cannot be autorequired")
+      else
+        cmd.scan(file_regex) { |str|
+          reqs << str
+        }
 
-      cmd.scan(/^"([^"]+)"/) { |str|
-        reqs << str
-      }
+        cmd.scan(/^"([^"]+)"/) { |str|
+          reqs << str
+        }
+      end
 
       [:onlyif, :unless].each { |param|
         tmp = self[param]
@@ -613,7 +617,11 @@ def check(value)
           # unqualified files, but, well, that's a bit more annoying
           # to do.
           line = line[0] if line.is_a? Array
-          reqs += line.scan(file_regex)
+          if line.is_a?(Puppet::Pops::Evaluator::DeferredValue)
+            self.debug("The '#{param}' parameter is deferred and cannot be autorequired")
+          else
+            reqs += line.scan(file_regex)
+          end
         end
       }
 

spec/unit/type/exec_spec.rb

@@ -252,6 +252,19 @@ def exec_stub(options = {})
     expect(dependencies.collect(&:to_s)).to eq([Puppet::Relationship.new(tmp, execer).to_s])
   end
 
+  it "skips autorequire for deferred commands" do
+    foo = make_absolute('/bin/foo')
+    catalog = Puppet::Resource::Catalog.new
+    tmp = Puppet::Type.type(:file).new(:name => foo)
+    execer = Puppet::Type.type(:exec).new(:name => 'test array', :command => Puppet::Pops::Evaluator::DeferredValue.new(nil))
+
+    catalog.add_resource tmp
+    catalog.add_resource execer
+    dependencies = execer.autorequire(catalog)
+
+    expect(dependencies.collect(&:to_s)).to eq([])
+  end
+
   describe "when handling the path parameter" do
     expect = %w{one two three four}
     { "an array"                                      => expect,