Move formatter to config

src/spectator/config.cr

@@ -1,5 +1,11 @@
 module Spectator
   # Provides customization and describes specifics for how Spectator will run and report tests.
   class Config
+    # Used to report test progress and results.
+    getter formatter : Formatters::Formatter
+
+    # Creates a new configuration.
+    def initialize(@formatter)
+    end
   end
 end

src/spectator/config_builder.cr

@@ -1,9 +1,31 @@
 module Spectator
+  # Mutable configuration used to produce a final configuration.
+  # Use the setters in this class to incrementally build a configuration.
+  # Then call `#build` to create the final configuration.
   class ConfigBuilder
-    property formatter : Formatters::Formatter = Formatters::DefaultFormatter.new
+    @formatter : Formatters::Formatter? = nil
 
-    def build
-      Config.new
+    # Sets the formatter to use for reporting test progress and results.
+    def formatter=(formatter : Formatters::Formatter)
+      @formatter = formatter
+    end
+
+    # Retrieves the formatter to use.
+    # If one wasn't specified by the user,
+    # then `#default_formatter` is returned.
+    private def formatter
+      @formatter || default_formatter
+    end
+
+    # The formatter that should be used,
+    # if one wasn't provided.
+    private def default_formatter
+      Formatters::DefaultFormatter.new
+    end
+
+    # Creates a configuration.
+    def build : Config
+      Config.new(formatter)
     end
   end
 end

src/spectator/runner.cr

@@ -1,25 +1,24 @@
 module Spectator
   # Main driver for executing tests and feeding results to formatters.
   class Runner
-    def initialize(@suite : TestSuite, config : Config)
-      @formatter = Formatters::DefaultFormatter.new
+    def initialize(@suite : TestSuite, @config : Config)
     end
 
     def run : Nil
       results = [] of Result
-      @formatter.start_suite
+      @config.formatter.start_suite
       elapsed = Time.measure do
         results = @suite.map do |example|
           run_example(example)
         end
       end
-      @formatter.end_suite(TestSuiteResults.new(results, elapsed))
+      @config.formatter.end_suite(TestSuiteResults.new(results, elapsed))
     end
 
     private def run_example(example)
-      @formatter.start_example(example)
+      @config.formatter.start_example(example)
       result = Internals::Harness.run(example)
-      @formatter.end_example(result)
+      @config.formatter.end_example(result)
       result
     end
   end