Add initial support for exect-receive syntax

spec/spectator/dsl/mocks/expect_receive_spec.cr

@@ -0,0 +1,80 @@
+require "../../../spec_helper"
+
+Spectator.describe "Deferred stub expectation DSL" do
+  context "with a double" do
+    double(:dbl) do
+      # Ensure the original is never called.
+      stub abstract def foo : Nil
+      stub abstract def foo(arg) : Nil
+    end
+
+    let(dbl) { double(:dbl) }
+
+    it "matches when a message is received" do
+      expect(dbl).to receive(:foo)
+      dbl.foo
+    end
+
+    it "matches when a message isn't received" do
+      expect(dbl).to_not receive(:foo)
+    end
+
+    it "matches when a message is received with matching arguments" do
+      expect(dbl).to receive(:foo).with(:bar)
+      dbl.foo(:bar)
+    end
+
+    it "matches when a message without arguments is received" do
+      expect(dbl).to_not receive(:foo).with(:bar)
+      dbl.foo
+    end
+
+    it "matches when a message without arguments isn't received" do
+      expect(dbl).to_not receive(:foo).with(:bar)
+    end
+
+    it "matches when a message with arguments isn't received" do
+      expect(dbl).to_not receive(:foo).with(:baz)
+      dbl.foo(:bar)
+    end
+  end
+
+  context "with a mock" do
+    abstract class MyClass
+      abstract def foo : Int32
+      abstract def foo(arg) : Int32
+    end
+
+    mock(MyClass)
+
+    let(fake) { mock(MyClass) }
+
+    it "matches when a message is received" do
+      expect(fake).to receive(:foo).and_return(42)
+      fake.foo(:bar)
+    end
+
+    it "matches when a message isn't received" do
+      expect(fake).to_not receive(:foo)
+    end
+
+    it "matches when a message is received with matching arguments" do
+      expect(fake).to receive(:foo).with(:bar).and_return(42)
+      fake.foo(:bar)
+    end
+
+    it "matches when a message without arguments is received" do
+      expect(fake).to_not receive(:foo).with(:bar)
+      fake.foo
+    end
+
+    it "matches when a message without arguments is received" do
+      expect(fake).to_not receive(:foo).with(:bar)
+    end
+
+    it "matches when a message with arguments isn't received" do
+      expect(fake).to_not receive(:foo).with(:baz).and_return(42)
+      fake.foo(:bar)
+    end
+  end
+end