its.rb in rspec-its-1.3.0

- old
+ new

@@ -53,29 +53,48 @@
     #
     #     its([:max_users]) { should eq(3) }
     #     its(['admin']) { should eq(:all_permissions) }
     #     its(['john_doe', :permissions]) { should eq([:read, :write]) }
     #
-    #     # You can still access to its regular methods this way:
+    #     # You can still access its regular methods this way:
     #     its(:keys) { should include(:max_users) }
     #     its(:count) { should eq(2) }
     #   end
     #
     # With an implicit subject, `is_expected` can be used as an alternative
-    # to `should` (e.g. for one-liner use)
+    # to `should` (e.g. for one-liner use). An `are_expected` alias is also
+    # supplied.
     #
     # @example
     #
     #   describe Array do
     #     its(:size) { is_expected.to eq(0) }
     #   end
     #
-    # You can pass more than one arguments on the `its` block to add
-    # some options to the generated example
+    # With an implicit subject, `will` can be used as an alternative
+    # to `expect { subject.attribute }.to matcher` (e.g. for one-liner use).
     #
     # @example
     #
+    #   describe Array do
+    #     its(:foo) { will raise_error(NoMethodError) }
+    #   end
+    #
+    # With an implicit subject, `will_not` can be used as an alternative
+    # to `expect { subject.attribute }.to_not matcher` (e.g. for one-liner use).
+    #
+    # @example
+    #
+    #   describe Array do
+    #     its(:size) { will_not raise_error }
+    #   end
+    #
+    # You can pass more than one argument on the `its` block to add
+    # some metadata to the generated example
+    #
+    # @example
+    #
     #   # This ...
     #   describe Array do
     #     its(:size, :focus) { should eq(0) }
     #   end
     #
@@ -119,9 +138,23 @@
 
         def is_expected
           expect(__its_subject)
         end
         alias_method :are_expected, :is_expected
+
+        def will(matcher=nil, message=nil)
+          unless matcher.supports_block_expectations?
+            raise ArgumentError, "`will` only supports block expectations"
+          end
+          expect { __its_subject }.to matcher, message
+        end
+
+        def will_not(matcher=nil, message=nil)
+          unless matcher.supports_block_expectations?
+            raise ArgumentError, "`will_not` only supports block expectations"
+          end
+          expect { __its_subject }.to_not matcher, message
+        end
 
         def should(matcher=nil, message=nil)
           RSpec::Expectations::PositiveExpectationHandler.handle_matcher(__its_subject, matcher, message)
         end
 