Add fail-fast to config

spec/runner_spec.cr

@@ -2,7 +2,9 @@ require "./spec_helper"
 
 # Creates a `Config` for Spectator that is suited for testing it.
 def spectator_test_config(formatter : Spectator::Formatting::Formatter? = nil)
-  Spectator::Config.new(formatter || Spectator::Formatting::SilentFormatter.new)
+  builder = Spectator::ConfigBuilder.new
+  builder.formatter = formatter || Spectator::Formatting::SilentFormatter.new
+  builder.build
 end
 
 def new_test_suite

src/spectator/command_line_arguments_config_source.cr

@@ -14,6 +14,7 @@ module Spectator
     def apply_to(builder : ConfigBuilder) : Nil
       OptionParser.parse(@args) do |parser|
         parser.on("-v", "--verbose", "Verbose output using document formatter") { builder.formatter = Formatting::DocumentFormatter.new }
+        parser.on("-f", "--fail-fast", "Stop testing on first failure") { builder.fail_fast }
       end
     end
   end

src/spectator/config.cr

@@ -4,9 +4,13 @@ module Spectator
     # Used to report test progress and results.
     getter formatter : Formatting::Formatter
 
+    # Indicates whether the test should abort on first failure.
+    getter? fail_fast : Bool
+
     # Creates a new configuration.
     def initialize(builder)
       @formatter = builder.formatter
+      @fail_fast = builder.fail_fast?
     end
   end
 end

src/spectator/config_builder.cr

@@ -9,6 +9,7 @@ module Spectator
     end
 
     @formatter : Formatting::Formatter? = nil
+    @fail_fast = false
 
     # Sets the formatter to use for reporting test progress and results.
     def formatter=(formatter : Formatting::Formatter)
@@ -28,6 +29,21 @@ module Spectator
       Formatting::DotsFormatter.new
     end
 
+    # Enables fail-fast mode.
+    def fail_fast
+      self.fail_fast = true
+    end
+
+    # Sets the fail-fast flag.
+    def fail_fast=(flag)
+      @fail_fast = flag
+    end
+
+    # Indicates whether fail-fast mode is enabled.
+    def fail_fast?
+      @fail_fast
+    end
+
     # Creates a configuration.
     def build : Config
       Config.new(self)