Initial support for and_yield

src/spectator/mocks/anonymous_double.cr

@@ -12,7 +12,11 @@ module Spectator::Mocks
       call = ::Spectator::Mocks::GenericMethodCall.new({{call.name.symbolize}}, args)
       ::Spectator::Harness.current.mocks.record_call(self, call)
       if (stub = ::Spectator::Harness.current.mocks.find_stub(self, call))
+        {% if call.block.is_a?(Nop) %}
           stub.call!(args, typeof(@values.fetch({{call.name.symbolize}}) { raise }))
+        {% else %}
+          stub.call!(args, typeof(@values.fetch({{call.name.symbolize}}) { raise })) { |*ya| yield *ya }
+        {% end %}
       else
         @values.fetch({{call.name.symbolize}}) do
           return nil if ::Spectator::Harness.current.mocks.expected?(self, {{call.name.symbolize}})

src/spectator/mocks/anonymous_null_double.cr

@@ -8,7 +8,11 @@ module Spectator::Mocks
       call = ::Spectator::Mocks::GenericMethodCall.new({{call.name.symbolize}}, args)
       ::Spectator::Harness.current.mocks.record_call(self, call)
       if (stub = ::Spectator::Harness.current.mocks.find_stub(self, call))
+        {% if call.block.is_a?(Nop) %}
           stub.call!(args, typeof(@values.fetch({{call.name.symbolize}}) { self }))
+        {% else %}
+          stub.call!(args, typeof(@values.fetch({{call.name.symbolize}}) { self })) { |*ya| yield *ya }
+        {% end %}
       else
         @values.fetch({{call.name.symbolize}}) { self }
       end

src/spectator/mocks/double.cr

@@ -45,12 +45,12 @@ module Spectator::Mocks
         end
       end
 
-      def {{name}}({{params.splat}}){% if definition.is_a?(TypeDeclaration) %} : {{definition.type}}{% end %}
+      def {{name}}({{params.splat}} &block){% if definition.is_a?(TypeDeclaration) %} : {{definition.type}}{% end %}
         %args = ::Spectator::Mocks::GenericArguments.create({{args.splat}})
         %call = ::Spectator::Mocks::GenericMethodCall.new({{name.symbolize}}, %args)
         ::Spectator::Harness.current.mocks.record_call(self, %call)
         if (%stub = ::Spectator::Harness.current.mocks.find_stub(self, %call))
-          %stub.call!(%args, typeof(%method({{args.splat}}) { |*%ya| yield *%ya }))
+          %stub.call!(%args, typeof(%method({{args.splat}}) { |*%ya| yield *%ya })) { |*%ya| yield *%ya }
         else
           %method({{args.splat}}) do |*%yield_args|
             yield *%yield_args

src/spectator/mocks/method_stub.cr

@@ -16,6 +16,10 @@ module Spectator::Mocks
 
     abstract def call(args : GenericArguments(T, NT), rt : RT.class) forall T, NT, RT
 
+    def call(args : GenericArguments(T, NT), rt : RT.class, &) forall T, NT, RT
+      call(args, rt)
+    end
+
     def call!(args : GenericArguments(T, NT), rt : RT.class) : RT forall T, NT, RT
       value = call(args, rt)
       if value.is_a?(RT)
@@ -25,6 +29,15 @@ module Spectator::Mocks
       end
     end
 
+    def call!(args : GenericArguments(T, NT), rt : RT.class) : RT forall T, NT, RT
+      value = call(args, rt) { |*ya| yield *ya }
+      if value.is_a?(RT)
+        value.as(RT)
+      else
+        raise TypeCastError.new("The return type of stub #{self} doesn't match the expected type #{RT}")
+      end
+    end
+
     def to_s(io)
       io << '#'
       io << @name

src/spectator/mocks/nil_method_stub.cr

@@ -36,6 +36,10 @@ module Spectator::Mocks
       ExceptionMethodStub.new(@name, @source, exception_type.new(*args), @args)
     end
 
+    def and_yield(*yield_args)
+      YieldMethodStub.new(@name, @source, yield_args, @args)
+    end
+
     def with(*args : *T, **opts : **NT) forall T, NT
       args = GenericArguments.new(args, opts)
       NilMethodStub.new(@name, @source, args)

src/spectator/mocks/yield_method_stub.cr

@@ -0,0 +1,19 @@
+require "./generic_arguments"
+require "./generic_method_stub"
+
+module Spectator::Mocks
+  class YieldMethodStub(YieldArgs) < GenericMethodStub(Nil)
+    def initialize(name, source, @yield_args : YieldArgs, args = nil)
+      super(name, source, args)
+    end
+
+    def call(_args : GenericArguments(T2, NT2), rt : RT.class) forall T2, NT2, RT
+      raise "Asked to yield |#{@yield_args}| but no block was passed"
+    end
+
+    def call(_args : GenericArguments(T2, NT2), rt : RT.class) forall T2, NT2, RT
+      yield *@yield_args
+      nil
+    end
+  end
+end