Support multiple formatters at once

src/spectator/config.cr

@@ -1,8 +1,7 @@
 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 : Formatting::Formatter
+    @formatters : Array(Formatting::Formatter)
 
     # Indicates whether the test should abort on first failure.
     getter? fail_fast : Bool
@@ -16,10 +15,17 @@ module Spectator
 
     # Creates a new configuration.
     def initialize(builder)
-      @formatter = builder.formatter
+      @formatters = builder.formatters
       @fail_fast = builder.fail_fast?
       @fail_blank = builder.fail_blank?
       @dry_run = builder.dry_run?
     end
+
+    # Yields each formatter that should be reported to.
+    def each_formatter
+      @formatters.each do |formatter|
+        yield formatter
+      end
+    end
   end
 end

src/spectator/config_builder.cr

@@ -8,21 +8,27 @@ module Spectator
       new.build
     end
 
-    @formatter : Formatting::Formatter? = nil
+    @primary_formatter : Formatting::Formatter?
+    @additional_formatters = [] of Formatting::Formatter
     @fail_fast = false
     @fail_blank = false
     @dry_run = false
 
-    # Sets the formatter to use for reporting test progress and results.
+    # Sets the primary formatter to use for reporting test progress and results.
     def formatter=(formatter : Formatting::Formatter)
-      @formatter = formatter
+      @primary_formatter = formatter
     end
 
-    # Retrieves the formatter to use.
+    # Adds an extra formater to use for reporting test progress and results.
+    def add_formatter(formatter : Formatting::Formatter)
+      @additional_formatters << formatter
+    end
+
+    # Retrieves the formatters to use.
     # If one wasn't specified by the user,
     # then `#default_formatter` is returned.
-    def formatter
-      @formatter || default_formatter
+    def formatters
+      @additional_formatters + [(@primary_formatter || default_formatter)]
     end
 
     # The formatter that should be used,

src/spectator/runner.cr

@@ -13,7 +13,7 @@ module Spectator
     # or false if there was at least one failure.
     def run : Bool
       # Indicate the suite is starting.
-      @config.formatter.start_suite(@suite)
+      @config.each_formatter(&.start_suite(@suite))
 
       # Run all examples and capture the results.
       results = Array(Result).new(@suite.size)
@@ -24,7 +24,7 @@ module Spectator
       # Generate a report and pass it along to the formatter.
       remaining = @suite.size - results.size
       report = Report.new(results, elapsed, remaining, @config.fail_blank?)
-      @config.formatter.end_suite(report)
+      @config.each_formatter(&.end_suite(report))
 
       !report.failed?
     end
@@ -41,13 +41,13 @@ module Spectator
     # Runs a single example and returns the result.
     # The formatter is given the example and result information.
     private def run_example(example)
-      @config.formatter.start_example(example)
+      @config.each_formatter(&.start_example(example))
       result = if @config.dry_run? && example.is_a?(RunnableExample)
                  dry_run_result(example)
                else
                  Internals::Harness.run(example)
                end
-      @config.formatter.end_example(result)
+      @config.each_formatter(&.end_example(result))
       result
     end