Test behavior and for leakages with allow syntax

spec/spectator/dsl/mocks/allow_receive_spec.cr

@@ -0,0 +1,188 @@
+require "../../../spec_helper"
+
+Spectator.describe "Allow stub 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
+      stub abstract def value : Int32
+    end
+
+    let(dbl) { double(:dbl) }
+
+    # Ensure invocations don't leak between examples.
+    pre_condition { expect(dbl).to_not have_received(:foo), "Leaked method calls from previous examples" }
+
+    # Ensure stubs don't leak between examples.
+    pre_condition do
+      expect { dbl.foo }.to raise_error(Spectator::UnexpectedMessage)
+    end
+
+    it "matches when a message is received" do
+      allow(dbl).to receive(:foo)
+      expect { dbl.foo }.to_not raise_error
+    end
+
+    it "returns the correct value" do
+      allow(dbl).to receive(:value).and_return(42)
+      expect(dbl.value).to eq(42)
+    end
+
+    it "matches when a message is received with matching arguments" do
+      allow(dbl).to receive(:foo).with(:bar)
+      expect { dbl.foo(:bar) }.to_not raise_error
+    end
+
+    it "raises when a message without arguments is received" do
+      allow(dbl).to receive(:foo).with(:bar)
+      expect { dbl.foo }.to raise_error(Spectator::UnexpectedMessage, /foo/)
+    end
+
+    it "raises when a message with different arguments is received" do
+      allow(dbl).to receive(:foo).with(:baz)
+      expect { dbl.foo(:bar) }.to raise_error(Spectator::UnexpectedMessage, /foo/)
+    end
+  end
+
+  context "with a class double" do
+    double(:dbl) do
+      # Ensure the original is never called.
+      abstract_stub def self.foo : Nil
+      end
+
+      abstract_stub def self.foo(arg) : Nil
+      end
+
+      abstract_stub def self.value : Int32
+        42
+      end
+    end
+
+    let(dbl) { class_double(:dbl) }
+
+    # Ensure invocations don't leak between examples.
+    pre_condition { expect(dbl).to_not have_received(:foo), "Leaked method calls from previous examples" }
+
+    # Ensure stubs don't leak between examples.
+    pre_condition do
+      expect { dbl.foo }.to raise_error(Spectator::UnexpectedMessage)
+    end
+
+    it "matches when a message is received" do
+      allow(dbl).to receive(:foo)
+      expect { dbl.foo }.to_not raise_error
+    end
+
+    it "returns the correct value" do
+      allow(dbl).to receive(:value).and_return(42)
+      expect(dbl.value).to eq(42)
+    end
+
+    it "matches when a message is received with matching arguments" do
+      allow(dbl).to receive(:foo).with(:bar)
+      expect { dbl.foo(:bar) }.to_not raise_error
+    end
+
+    it "raises when a message without arguments is received" do
+      allow(dbl).to receive(:foo).with(:bar)
+      expect { dbl.foo }.to raise_error(Spectator::UnexpectedMessage, /foo/)
+    end
+
+    it "raises when a message with different arguments is received" do
+      allow(dbl).to receive(:foo).with(:baz)
+      expect { dbl.foo(:bar) }.to raise_error(Spectator::UnexpectedMessage, /foo/)
+    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) }
+
+    # Ensure invocations don't leak between examples.
+    pre_condition { expect(fake).to_not have_received(:foo), "Leaked method calls from previous examples" }
+
+    # Ensure stubs don't leak between examples.
+    pre_condition do
+      expect { fake.foo }.to raise_error(Spectator::UnexpectedMessage)
+    end
+
+    it "matches when a message is received" do
+      allow(fake).to receive(:foo).and_return(42)
+      expect(fake.foo).to eq(42)
+    end
+
+    it "returns the correct value" do
+      allow(fake).to receive(:foo).and_return(42)
+      expect(fake.foo).to eq(42)
+    end
+
+    it "matches when a message is received with matching arguments" do
+      allow(fake).to receive(:foo).with(:bar).and_return(42)
+      expect(fake.foo(:bar)).to eq(42)
+    end
+
+    it "raises when a message without arguments is received" do
+      allow(fake).to receive(:foo).with(:bar)
+      expect { fake.foo }.to raise_error(Spectator::UnexpectedMessage, /foo/)
+    end
+
+    it "raises when a message with different arguments is received" do
+      allow(fake).to receive(:foo).with(:baz)
+      expect { fake.foo(:bar) }.to raise_error(Spectator::UnexpectedMessage, /foo/)
+    end
+  end
+
+  context "with a class mock" do
+    class MyClass
+      def self.foo : Int32
+        42
+      end
+
+      def self.foo(arg) : Int32
+        42
+      end
+    end
+
+    mock(MyClass)
+
+    let(fake) { class_mock(MyClass) }
+
+    # Ensure invocations don't leak between examples.
+    pre_condition { expect(fake).to_not have_received(:foo), "Leaked method calls from previous examples" }
+
+    # Ensure stubs don't leak between examples.
+    pre_condition { expect(fake.foo).to eq(42) }
+
+    it "matches when a message is received" do
+      allow(fake).to receive(:foo).and_return(0)
+      expect(fake.foo).to eq(0)
+    end
+
+    it "returns the correct value" do
+      allow(fake).to receive(:foo).and_return(0)
+      expect(fake.foo).to eq(0)
+    end
+
+    it "matches when a message is received with matching arguments" do
+      allow(fake).to receive(:foo).with(:bar).and_return(0)
+      expect(fake.foo(:bar)).to eq(0)
+    end
+
+    it "calls the original when a message without arguments is received" do
+      allow(fake).to receive(:foo).with(:bar)
+      expect(fake.foo).to eq(42)
+    end
+
+    it "calls the original when a message with different arguments is received" do
+      allow(fake).to receive(:foo).with(:baz)
+      expect(fake.foo(:bar)).to eq(42)
+    end
+  end
+end