From 31d58fea25f2e00b779ef14cd34bf9e082839a05 Mon Sep 17 00:00:00 2001
From: Michael Miller <icy.arctic.fox@gmail.com>
Date: Fri, 22 Mar 2019 13:21:37 -0600
Subject: [PATCH] Add "fail-blank" config option

---
 .../command_line_arguments_config_source.cr     |  1 +
 src/spectator/config.cr                         |  4 ++++
 src/spectator/config_builder.cr                 | 17 +++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/src/spectator/command_line_arguments_config_source.cr b/src/spectator/command_line_arguments_config_source.cr
index e544d10..92982d1 100644
--- a/src/spectator/command_line_arguments_config_source.cr
+++ b/src/spectator/command_line_arguments_config_source.cr
@@ -15,6 +15,7 @@ module Spectator
       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 }
+        parser.on("-b", "--fail-blank", "Fail if there are no examples") { builder.fail_blank }
         parser.on("-h", "--help", "Show this help") { puts parser; exit }
         parser.on("-e", "--example STRING", "Run examples whose full nested names include STRING") { |pattern| raise NotImplementedError.new("-e") }
         parser.on("-l", "--line LINE", "Run examples whose line matches LINE") { |line| raise NotImplementedError.new("-l") }
diff --git a/src/spectator/config.cr b/src/spectator/config.cr
index 1524ace..64dc143 100644
--- a/src/spectator/config.cr
+++ b/src/spectator/config.cr
@@ -7,10 +7,14 @@ module Spectator
     # Indicates whether the test should abort on first failure.
     getter? fail_fast : Bool
 
+    # Indicates whether the test should fail if there are no examples.
+    getter? fail_blank : Bool
+
     # Creates a new configuration.
     def initialize(builder)
       @formatter = builder.formatter
       @fail_fast = builder.fail_fast?
+      @fail_blank = builder.fail_blank?
     end
   end
 end
diff --git a/src/spectator/config_builder.cr b/src/spectator/config_builder.cr
index b26e6ac..22c93d2 100644
--- a/src/spectator/config_builder.cr
+++ b/src/spectator/config_builder.cr
@@ -10,6 +10,7 @@ module Spectator
 
     @formatter : Formatting::Formatter? = nil
     @fail_fast = false
+    @fail_blank = false
 
     # Sets the formatter to use for reporting test progress and results.
     def formatter=(formatter : Formatting::Formatter)
@@ -44,6 +45,22 @@ module Spectator
       @fail_fast
     end
 
+    # Enables fail-blank mode (fail on no tests).
+    def fail_blank
+      self.fail_blank = true
+    end
+
+    # Sets teh fail-blank mode.
+    def fail_blank=(flag)
+      @fail_blank = flag
+    end
+
+    # Indicates whether fail-fast mode is enabled.
+    # That is, it is a failure if there are no tests.
+    def fail_blank?
+      @fail_blank
+    end
+
     # Creates a configuration.
     def build : Config
       Config.new(self)