DEV: support --fail-fast in bin/turbo_rspec (#8170)

* [WIP] - default turbo spec env to test

* FEATURE: support for --fast-fail in bin/turbo_rspec

* fast-fail -> fail_fast to match rspec

* Moved thread killing outside of fail-fast check

* Removed failure_count incrementation from fast_fail_met

lib/turbo_tests/runner.rb

@@ -7,6 +7,7 @@ module TurboTests
       formatters = opts[:formatters]
       start_time = opts.fetch(:start_time) { Time.now }
       verbose = opts.fetch(:verbose, false)
+      fail_fast = opts.fetch(:fail_fast, nil)
 
       if verbose
         STDERR.puts "VERBOSE"
@@ -17,7 +18,8 @@ module TurboTests
       new(
         reporter: reporter,
         files: files,
-        verbose: verbose
+        verbose: verbose,
+        fail_fast: fail_fast
       ).run
     end
 
@@ -25,6 +27,8 @@ module TurboTests
       @reporter = opts[:reporter]
       @files = opts[:files]
       @verbose = opts[:verbose]
+      @fail_fast = opts[:fail_fast]
+      @failure_count = 0
 
       @messages = Queue.new
       @threads = []
@@ -215,6 +219,11 @@ module TurboTests
           when 'example_failed'
             example = FakeExample.from_obj(message[:example])
             @reporter.example_failed(example)
+            @failure_count += 1
+            if fail_fast_met
+              @threads.each(&:kill)
+              break
+            end
           when 'seed'
           when 'close'
           when 'exit'
@@ -231,5 +240,9 @@ module TurboTests
       rescue Interrupt
       end
     end
+
+    def fail_fast_met
+      !@fail_fast.nil? && @fail_fast >= @failure_count
+    end
   end
 end