Display "None" when no methods are called

spec/matchers/receive_matcher_spec.cr

@@ -164,16 +164,17 @@ Spectator.describe Spectator::Matchers::ReceiveMatcher do
 
       pre_condition { expect(match_data).to be_a(failed_match) }
 
+      it "has the expected call listed" do
+        is_expected.to contain({:expected, "#test_method(1, \"test\", Symbol, foo: #{/bar/.inspect})"})
+      end
+
+      context "with method calls" do
         before_each do
           dbl.test_method
           dbl.test_method(1, "wrong", :xyz, foo: "foobarbaz")
           dbl.irrelevant("foo")
         end
 
-      it "has the expected call listed" do
-        is_expected.to contain({:expected, "#test_method(1, \"test\", Symbol, foo: #{/bar/.inspect})"})
-      end
-
         it "has the list of called methods" do
           is_expected.to contain({
             :actual,
@@ -185,6 +186,13 @@ Spectator.describe Spectator::Matchers::ReceiveMatcher do
           })
         end
       end
+
+      context "with no method calls" do
+        it "reports \"None\" for the actual value" do
+          is_expected.to contain({:actual, "None"})
+        end
+      end
+    end
   end
 
   describe "#negated_match" do

src/spectator/matchers/receive_matcher.cr

@@ -62,7 +62,7 @@ module Spectator::Matchers
     private def values(actual : Expression(T)) forall T
       {
         expected: @stub.to_s,
-        actual:   actual.value._spectator_calls.join("\n"),
+        actual:   method_call_list(actual.value),
       }
     end
 
@@ -70,8 +70,18 @@ module Spectator::Matchers
     private def negated_values(actual : Expression(T)) forall T
       {
         expected: "Not #{@stub}",
-        actual:   actual.value._spectator_calls.join("\n"),
+        actual:   method_call_list(actual.value),
       }
     end
+
+    # Formatted list of method calls.
+    private def method_call_list(stubbable)
+      calls = stubbable._spectator_calls
+      if calls.empty?
+        "None"
+      else
+        calls.join("\n")
+      end
+    end
   end
 end