Add lazy double

spec/spectator/dsl/mocks/lazy_double_spec.cr

@@ -0,0 +1,60 @@
+require "../../../spec_helper"
+
+Spectator.describe "Lazy double DSL" do
+  context "specifying methods as keyword args" do
+    subject(dbl) { double(:test, foo: "foobar", bar: 42) }
+
+    it "defines a double with methods" do
+      aggregate_failures do
+        expect(dbl.foo).to eq("foobar")
+        expect(dbl.bar).to eq(42)
+      end
+    end
+
+    context "with an unexpected message" do
+      it "raises an error" do
+        expect { dbl.baz }.to raise_error(Spectator::UnexpectedMessage, /baz/)
+      end
+
+      it "reports the double name" do
+        expect { dbl.baz }.to raise_error(Spectator::UnexpectedMessage, /:test/)
+      end
+
+      it "reports the arguments" do
+        expect { dbl.baz(:xyz, 123, a: "XYZ") }.to raise_error(Spectator::UnexpectedMessage, /\(:xyz, 123, a: "XYZ"\)/)
+      end
+    end
+
+    context "blocks" do
+      it "supports blocks" do
+        aggregate_failures do
+          expect(dbl.foo { nil }).to eq("foobar")
+          expect(dbl.bar { nil }).to eq(42)
+        end
+      end
+
+      it "fails on undefined messages" do
+        expect do
+          dbl.baz { nil }
+        end.to raise_error(Spectator::UnexpectedMessage, /baz/)
+      end
+    end
+  end
+
+  describe "double naming" do
+    it "accepts a symbolic double name" do
+      dbl = double(:name)
+      expect { dbl.oops }.to raise_error(Spectator::UnexpectedMessage, /:name/)
+    end
+
+    it "accepts a string double name" do
+      dbl = double("Name")
+      expect { dbl.oops }.to raise_error(Spectator::UnexpectedMessage, /"Name"/)
+    end
+
+    it "accepts no name" do
+      dbl = double
+      expect { dbl.oops }.to raise_error(Spectator::UnexpectedMessage, /anonymous/i)
+    end
+  end
+end