Define test context types

src/spectator/context.cr

@@ -0,0 +1,8 @@
+require "../spectator_context"
+
+module Spectator
+  # Base class that all test cases run in.
+  # This type is used to store all test case contexts as a single type.
+  # The instance must be downcast to the correct type before calling a context method.
+  alias Context = ::SpectatorContext
+end

src/spectator/context_delegate.cr

@@ -0,0 +1,18 @@
+require "./context"
+require "./context_method"
+
+module Spectator
+  # Stores a test context and a method to call within it.
+  struct ContextDelegate
+    # Creates the delegate.
+    # The *context* is the instance of the test context.
+    # The *method* is proc that downcasts *context* and calls a method on it.
+    def initialize(@context : Context, @method : ContextMethod)
+    end
+
+    # Invokes a method in the test context.
+    def call
+      @method.call(@context)
+    end
+  end
+end

src/spectator/context_method.cr

@@ -0,0 +1,10 @@
+require "./context"
+
+module Spectator
+  # Encapsulates a method in a context.
+  # This could be used to invoke a test case or hook method.
+  # The context is passed as an argument.
+  # The proc should downcast the context instance to the desired type
+  # and call a method on that context.
+  alias ContextMethod = Context ->
+end

src/spectator_contnext.cr

@@ -0,0 +1,7 @@
+# Base class that all test cases run in.
+# This type is used to store all test case contexts as a single type.
+# The instance must be downcast to the correct type before calling a context method.
+# This type is intentionally outside the `Spectator` module.
+# The reason for this is to prevent name collision when using the DSL to define a spec.
+abstract class SpectatorContext
+end