Set up typechecking for DSL blocks

Author: dersam

dsl/prototype.rb

@@ -1,6 +1,8 @@
-# typed: false
+# typed: true
 # frozen_string_literal: true
 
+#: self as Roast::DSL::Executor
+
 config do
   cmd(:echo) { print_all! }
 end

lib/roast/dsl/config_context.rb

@@ -1,4 +1,4 @@
-# typed: false
+# typed: true
 # frozen_string_literal: true
 
 module Roast

lib/roast/dsl/execution_context.rb

@@ -1,4 +1,4 @@
-# typed: false
+# typed: true
 # frozen_string_literal: true
 
 module Roast

lib/roast/dsl/executor.rb

@@ -58,10 +58,12 @@ def completed?
         @completed ||= false
       end
 
+      #: { () [self: ConfigContext] -> void} -> void
       def config(&block)
         @config_proc = block
       end
 
+      #: { () [self: ExecutionContext] -> void} -> void
       def execute(&block)
         @execution_proc = block
       end

sorbet/rbi/shims/lib/roast/dsl/config_context.rbi

@@ -0,0 +1,10 @@
+# typed: true
+# frozen_string_literal: true
+
+module Roast
+  module DSL
+    class ConfigContext
+      def cmd(name = nil, &block); end
+    end
+  end
+end

sorbet/rbi/shims/lib/roast/dsl/execution_context.rbi

@@ -0,0 +1,11 @@
+# typed: true
+# frozen_string_literal: true
+
+module Roast
+  module DSL
+    class ExecutionContext
+      #: (?String?) -> void
+      def cmd(name = nil, &block); end
+    end
+  end
+end