Allow fail_fast to be passed as a string

Author: vfonic

lib/rspec/core/configuration.rb

@@ -202,10 +202,33 @@ def only_failures_but_not_configured?
         only_failures? && !example_status_persistence_file_path
       end
 
-      # @macro add_setting
+      # @macro define_reader
       # If specified, indicates the number of failures required before cleaning
-      # up and exit (default: `nil`).
-      add_setting :fail_fast
+      # up and exit (default: `nil`). Can also be `true` to fail and exit on first
+      # failure
+      define_reader :fail_fast
+
+      # @see fail_fast
+      def fail_fast=(value)
+        case value
+        when true, 'true'
+          @fail_fast = true
+        when false, 'false', 0
+          @fail_fast = false
+        when nil
+          @fail_fast = nil
+        else
+          @fail_fast = value.to_i
+
+          if value.to_i == 0
+            # TODO: in RSpec 4, consider raising an error here.
+            RSpec.warning "Cannot set `RSpec.configuration.fail_fast`" \
+              " to `#{value.inspect}`. Only `true`, `false`, `nil` and integers" \
+              " are valid values."
+            @fail_fast = true
+          end
+        end
+      end
 
       # @macro add_setting
       # Prints the formatter output of your suite without running any

spec/rspec/core/configuration_spec.rb

@@ -41,6 +41,87 @@ module RSpec::Core
       end
     end
 
+    describe "#fail_fast=" do
+      context 'when true' do
+        it 'is set to true' do
+          config.fail_fast = true
+          expect(config.fail_fast).to eq true
+        end
+      end
+
+      context "when 'true'" do
+        it 'is set to true' do
+          config.fail_fast = 'true'
+          expect(config.fail_fast).to eq true
+        end
+      end
+
+      context "when false" do
+        it 'is set to false' do
+          config.fail_fast = false
+          expect(config.fail_fast).to eq false
+        end
+      end
+
+      context "when 'false'" do
+        it 'is set to false' do
+          config.fail_fast = 'false'
+          expect(config.fail_fast).to eq false
+        end
+      end
+
+      context "when 0" do
+        it 'is set to false' do
+          config.fail_fast = 0
+          expect(config.fail_fast).to eq false
+        end
+      end
+
+      context "when integer number" do
+        it 'is set to number' do
+          config.fail_fast = 5
+          expect(config.fail_fast).to eq 5
+        end
+      end
+
+      context "when floating point number" do
+        it 'is set to integer number' do
+          config.fail_fast = 5.9
+          expect(config.fail_fast).to eq 5
+        end
+      end
+
+      context "when string represeting an integer number" do
+        it 'is set to number' do
+          config.fail_fast = '5'
+          expect(config.fail_fast).to eq 5
+        end
+      end
+
+      context "when nil" do
+        it 'is nil' do
+          config.fail_fast = nil
+          expect(config.fail_fast).to eq nil
+        end
+      end
+
+      context "when unrecognized value" do
+        before do
+          allow(RSpec).to receive(:warning)
+        end
+
+        it 'prints warning' do
+          config.fail_fast = 'yes'
+          expect(RSpec).to have_received(:warning).with(/Cannot set `RSpec.configuration.fail_fast`/i)
+        end
+
+        it 'is set to true' do
+          config.fail_fast = 'yes'
+          expect(config.fail_fast).to eq true
+        end
+      end
+    end
+
     describe 'fail_if_no_examples' do
       it 'defaults to false' do
         expect(RSpec::Core::Configuration.new.fail_if_no_examples).to be(false)