Update enabled methods defined for Query::Solution to include public_methods, and method`.

Note overridden instance methods and deprecate their usage.

Author: gkellogg

lib/rdf/query/solution.rb

@@ -23,10 +23,13 @@ class RDF::Query
   class Solution
     # Undefine all superfluous instance methods:
     alias_method :__send, :send
+
+    # Temporarily remember instance method for deprecation message in `method_missing`.
+    INSTANCE_METHODS = instance_methods
     undef_method(*instance_methods.
                   map(&:to_s).
                   select {|m| m.match?(/^\w+$/)}.
-                  reject {|m| %w(object_id dup instance_eval inspect to_s private_methods class should should_not pretty_print).include?(m) || m[0,2] == '__'}.
+                  reject {|m| %w(object_id dup instance_eval inspect to_s private_methods public_methods class method pretty_print).include?(m) || m[0,2] == '__'}.
                   map(&:to_sym))
 
     include Enumerable
@@ -344,6 +347,12 @@ def inspect
     #   @return [RDF::Term]
     def method_missing(name, *args, &block)
       if args.empty? && @bindings.key?(name.to_sym)
+        if INSTANCE_METHODS.include?(name)
+          warn "[DEPRECATION] RDF::Query::Solution##{name} is an overridden instance method.\n" +
+               "Its use as a solution accessor is deprecated and will be removed in a future version.\n" +
+               "Use #[] for safe access.\n" +
+               "Called from #{Gem.location_of_caller.join(':')}"
+        end
         @bindings[name.to_sym]
       else
         super # raises NoMethodError

spec/query_solution_spec.rb

@@ -9,6 +9,30 @@
     end
   end
 
+  describe "accessors" do
+    specify {expect(subject.a).to eq 1}
+    specify {expect(subject[:a]).to eq 1}
+    specify {expect(subject["a"]).to eq 1}
+    specify {expect(subject["?b"]).to eq 2}
+    specify {expect(subject["??c"]).to eq 3}
+    specify {expect(subject["$d"]).to eq 4}
+    specify {expect(subject["$$e"]).to eq 5}
+
+    context "with accessor overriding instance method" do
+      subject {described_class.new(then: 'foo')}
+
+      it "notes deprecation when accessor is an overriddedn instance method" do
+        expect do
+          expect(subject.then).to eq 'foo'
+        end.to write('[DEPRECATION]').to(:error)
+
+        expect do
+          expect(subject[:then]).to eq 'foo'
+        end.not_to write.to(:error)
+      end
+    end
+  end
+
   describe "#each_binding" do
     it "returns an enumerator" do
       expect(subject.each_binding).to be_an Enumerator