1 files changed, 84 insertions, 0 deletions
diff --git a/spec/unit/node_spec.rb b/spec/unit/node_spec.rb
index a78ad2c076..3b9501d73c 100644
--- a/spec/unit/node_spec.rb
+++ b/spec/unit/node_spec.rb
@@ -1709,4 +1709,88 @@ describe Chef::Node do
     end
   end
 
+  describe "path tracking via __path" do
+    it "works through hash keys" do
+      node.default["foo"] = { "bar" => { "baz" => "qux" } }
+      expect(node["foo"]["bar"].__path).to eql(%w{foo bar})
+    end
+
+    it "works through the default level" do
+      node.default["foo"] = { "bar" => { "baz" => "qux" } }
+      expect(node.default["foo"]["bar"].__path).to eql(%w{foo bar})
+    end
+
+    it "works through arrays" do
+      node.default["foo"] = [ { "bar" => { "baz" => "qux" } } ]
+      expect(node["foo"][0].__path).to eql(["foo", 0])
+      expect(node["foo"][0]["bar"].__path).to eql(["foo", 0, "bar"])
+    end
+
+    it "works through arrays at the default level" do
+      node.default["foo"] = [ { "bar" => { "baz" => "qux" } } ]
+      expect(node.default["foo"][0].__path).to eql(["foo", 0])
+      expect(node.default["foo"][0]["bar"].__path).to eql(["foo", 0, "bar"])
+    end
+
+    # if we set __path in the initializer we'd get this wrong, this is why we
+    # update the path on every #[] or #[]= operator
+    it "works on access when the node has been rearranged" do
+      node.default["foo"] = { "bar" => { "baz" => "qux" } }
+      a = node.default["foo"]
+      node.default["fizz"] = a
+      expect(node["fizz"]["bar"].__path).to eql(%w{fizz bar})
+      expect(node["foo"]["bar"].__path).to eql(%w{foo bar})
+    end
+
+    # We have a problem because the __path is stored on in each node, but the
+    # node can be wired up at multiple locations in the tree via pointers.  One
+    # solution would be to deep-dup the value in `#[]=(key, value)` and fix the
+    # __path on all the dup'd nodes.  The problem is that this would create an
+    # unusual situation where after assignment, you couldn't mutate the thing you
+    # hand a handle on.  I'm not entirely positive this behavior is the correct
+    # thing to support, but it is more hash-like (although if we start with a hash
+    # then convert_value does its thing and we *do* get dup'd on assignment).  This
+    # behavior likely makes any implementation of a deep merge cache built over the
+    # top of __path tracking have edge conditions where it will fail.
+    #
+    # Removing this support would be a breaking change.  The test is included here
+    # because it seems most likely that someone would break this behavior while trying
+    # to fix __path behavior.
+    it "does not dup in the background when a node is assigned" do
+      # get a handle on a vividmash (can't be a hash or else we convert_value it)
+      node.default["foo"] = { "bar" => { "baz" => "qux" } }
+      a = node.default["foo"]
+      # assign that somewhere else in the tree
+      node.default["fizz"] = a
+      # now upate the source
+      a["duptest"] = true
+      # the tree should have been updated
+      expect(node.default["fizz"]["duptest"]).to be true
+      expect(node["fizz"]["duptest"]).to be true
+    end
+  end
+
+  describe "root tracking via __root" do
+    it "works through hash keys" do
+      node.default["foo"] = { "bar" => { "baz" => "qux" } }
+      expect(node["foo"]["bar"].__root).to eql(node.attributes)
+    end
+
+    it "works through the default level" do
+      node.default["foo"] = { "bar" => { "baz" => "qux" } }
+      expect(node.default["foo"]["bar"].__root).to eql(node.attributes)
+    end
+
+    it "works through arrays" do
+      node.default["foo"] = [ { "bar" => { "baz" => "qux" } } ]
+      expect(node["foo"][0].__root).to eql(node.attributes)
+      expect(node["foo"][0]["bar"].__root).to eql(node.attributes)
+    end
+
+    it "works through arrays at the default level" do
+      node.default["foo"] = [ { "bar" => { "baz" => "qux" } } ]
+      expect(node.default["foo"][0].__root).to eql(node.attributes)
+      expect(node.default["foo"][0]["bar"].__root).to eql(node.attributes)
+    end
+  end
 end