Add basics for tracking source code location

src/spectator.cr

@@ -9,7 +9,7 @@ module Spectator
   macro describe(what, source_file = __FILE__, source_line = __LINE__, &block)
     module Spectator
       module Examples
-        DSL.describe({{what}}) {{block}}
+        DSL.describe({{what}}, {{source_file}}, {{source_line}}) {{block}}
       end
     end
   end

src/spectator/dsl.cr

@@ -2,11 +2,11 @@ require "./example_group"
 
 module Spectator
   module DSL
-    macro describe(what, type = "Describe", &block)
-      context({{what}}, {{type}}) {{block}}
+    macro describe(what, source_file = __FILE__, source_line = __LINE__, type = "Describe", &block)
+      context({{what}}, {{source_file}}, {{source_line}}, {{type}}) {{block}}
     end
 
-    macro context(what, type = "Context", &block)
+    macro context(what, source_file = __FILE__, source_line = __LINE__, type = "Context", &block)
       {% safe_name = what.id.stringify.gsub(/\W+/, "_") %}
       {% module_name = (type.id + safe_name.camelcase).id %}
       {% parent_context_name = PARENT_CONTEXT_NAME %}
@@ -23,12 +23,16 @@ module Spectator
       end
     end
 
-    macro it(description, &block)
+    macro it(description, source_file = __FILE__, source_line = __LINE__, &block)
       {% safe_name = description.id.stringify.gsub(/\W+/, "_") %}
       {% class_name = (safe_name.camelcase + "Example").id %}
       class {{class_name.id}} < ::Spectator::Example
         include Context
 
+        def source
+          Source.new({{source_file}}, {{source_line}})
+        end
+
         def run
           {{block.body}}
         end

src/spectator/example.cr

@@ -1,9 +1,13 @@
+require "./source"
+
 module Spectator
   abstract class Example
     macro is_expected
       expect(subject)
     end
-    
+
+    abstract def source : Source
+
     abstract def run
   end
 end

src/spectator/source.cr

@@ -0,0 +1,15 @@
+module Spectator
+  class Source
+    getter file : String
+    getter line : Int32
+
+    def initialize(@file, @line)
+    end
+
+    def to_s(io)
+      io << file
+      io << ':'
+      io << line
+    end
+  end
+end