Move #start_with from URI to Value and add specs.

Author: gkellogg

lib/rdf/model/uri.rb

@@ -673,22 +673,6 @@ def freeze
       self
     end
 
-    ##
-    # Returns `true` if this URI starts with the given `string`.
-    #
-    # @example
-    #   RDF::URI('http://example.org/').start_with?('http')     #=> true
-    #   RDF::URI('http://example.org/').start_with?('ftp')      #=> false
-    #
-    # @param  [String, #to_s] string
-    # @return [Boolean] `true` or `false`
-    # @see    String#start_with?
-    # @since  0.3.0
-    def start_with?(string)
-      to_s.start_with?(string.to_s)
-    end
-    alias_method :starts_with?, :start_with?
-
     ##
     # Returns `true` if this URI ends with the given `string`.
     #

lib/rdf/model/value.rb

@@ -159,6 +159,23 @@ def validate!
     end
     alias_method :validate, :validate!
 
+    ##
+    # Returns `true` if this Value starts with the given `string`.
+    #
+    # @example
+    #   RDF::URI('http://example.org/').start_with?('http')     #=> true
+    #   RDF::Node('_:foo').start_with?('_:bar')                 #=> false
+    #   RDF::Litera('Apple').start_with?('Orange')              #=> false
+    #
+    # @param  [String, #to_s] string
+    # @return [Boolean] `true` or `false`
+    # @see    String#start_with?
+    # @since  0.3.0
+    def start_with?(string)
+      to_s.start_with?(string.to_s)
+    end
+    alias_method :starts_with?, :start_with?
+
     ##
     # Returns a copy of this value converted into its canonical
     # representation.

spec/model_literal_spec.rb

@@ -155,6 +155,11 @@ def self.literals(*selector)
     end
   end
 
+  it "#start_with?" do
+    expect(RDF::Literal('foo')).to be_start_with('foo')
+    expect(RDF::Literal('bar')).not_to be_start_with('foo')
+  end
+
   describe "#==" do
     literals(:all_plain).each do |args|
       it "returns true for #{args.inspect}" do

spec/model_node_spec.rb

@@ -56,6 +56,11 @@
     specify {expect(RDF::Node.intern(:a)).to eql RDF::Node.intern("a")}
   end
 
+  it "#start_with?" do
+    expect(RDF::Node('foo')).to be_start_with('_:foo')
+    expect(RDF::Node('bar')).not_to be_start_with('_:foo')
+  end
+
   subject {new.call("foo")}
 
   describe "#dup" do