Merge pull request #405 from sferik/be_between

Add RSpec::Matchers::BuiltIn::BeBetween

.travis.yml

@@ -1,5 +1,10 @@
-script: "script/test_all"
+before_install:
+  - gem update bundler
+  - bundle --version
+  - gem update --system 2.1.11
+  - gem --version
 bundler_args: "--standalone --binstubs --without documentation"
+script: "script/test_all"
 rvm:
   - 1.8.7
   - 1.9.2
@@ -8,10 +13,13 @@ rvm:
   - 2.1.0
   - jruby-18mode
   - jruby-19mode
-  - ree
+  - jruby-head
   - rbx
-before_install:
-  - gem update bundler
-  - bundle --version
-  - gem update --system 2.1.11
-  - gem --version
+  - ree
+  - ruby-head
+matrix:
+  allow_failures:
+    - rvm: jruby-head
+    - rvm: ruby-head
+  fast_finish: true
+

lib/rspec/matchers.rb

@@ -317,6 +317,21 @@ def be_a_kind_of(expected)
     alias_method  :be_kind_of, :be_a_kind_of
     alias_matcher :a_kind_of,  :be_a_kind_of
 
+    # Passes if actual.between?(min, max). Works with any Comparable object,
+    # including String, Symbol, Time, or Numeric (Fixnum, Bignum, Integer,
+    # Float, Complex, and Rational).
+    #
+    # @note Inclusive of both min and max values.
+    #
+    # @example
+    #
+    #   expect(5).to      be_between(1, 10)
+    #   expect(11).not_to be_between(1, 10)
+    def be_between(min, max)
+      BuiltIn::BeBetween.new(min, max)
+    end
+    alias_matcher :a_value_between, :be_between
+
     # Passes if actual == expected +/- delta
     #
     # @example

lib/rspec/matchers/built_in.rb

@@ -3,14 +3,15 @@
 module RSpec
   module Matchers
     module BuiltIn
+      autoload :BeAKindOf,               'rspec/matchers/built_in/be_kind_of'
       autoload :BeAnInstanceOf,          'rspec/matchers/built_in/be_instance_of'
+      autoload :BeBetween,               'rspec/matchers/built_in/be_between'
       autoload :Be,                      'rspec/matchers/built_in/be'
-      autoload :BeTruthy,                'rspec/matchers/built_in/be'
+      autoload :BeComparedTo,            'rspec/matchers/built_in/be'
       autoload :BeFalsey,                'rspec/matchers/built_in/be'
       autoload :BeNil,                   'rspec/matchers/built_in/be'
-      autoload :BeComparedTo,            'rspec/matchers/built_in/be'
       autoload :BePredicate,             'rspec/matchers/built_in/be'
-      autoload :BeAKindOf,               'rspec/matchers/built_in/be_kind_of'
+      autoload :BeTruthy,                'rspec/matchers/built_in/be'
       autoload :BeWithin,                'rspec/matchers/built_in/be_within'
       autoload :Change,                  'rspec/matchers/built_in/change'
       autoload :Compound,                'rspec/matchers/built_in/compound'
@@ -33,11 +34,9 @@ module BuiltIn
       autoload :StartWith,               'rspec/matchers/built_in/start_and_end_with'
       autoload :ThrowSymbol,             'rspec/matchers/built_in/throw_symbol'
       autoload :YieldControl,            'rspec/matchers/built_in/yield'
+      autoload :YieldSuccessiveArgs,     'rspec/matchers/built_in/yield'
       autoload :YieldWithArgs,           'rspec/matchers/built_in/yield'
       autoload :YieldWithNoArgs,         'rspec/matchers/built_in/yield'
-      autoload :YieldSuccessiveArgs,     'rspec/matchers/built_in/yield'
     end
   end
 end
-
-

lib/rspec/matchers/built_in/be_between.rb

@@ -0,0 +1,40 @@
+module RSpec
+  module Matchers
+    module BuiltIn
+      class BeBetween < BaseMatcher
+        include Composable
+
+        def initialize(min, max)
+          @min, @max = min, max
+        end
+
+        def matches?(actual)
+          @actual = actual
+          comparable? and @actual.between?(@min, @max)
+        end
+
+        def failure_message
+          "expected #{@actual.inspect} to #{description}#{not_comparable_clause}"
+        end
+
+        def failure_message_when_negated
+          "expected #{@actual.inspect} not to #{description}"
+        end
+
+        def description
+          "be between #{@min.inspect} and #{@max.inspect} (inclusive)"
+        end
+
+      private
+
+        def comparable?
+          @actual.respond_to?(:between?)
+        end
+
+        def not_comparable_clause
+          ", but #{@actual.inspect} does not respond to `between?`" unless comparable?
+        end
+      end
+    end
+  end
+end

lib/rspec/matchers/built_in/be_within.rb

@@ -33,7 +33,7 @@ def failure_message
         end
 
         def failure_message_when_negated
-          "expected #{@actual} not to #{description}"
+          "expected #{@actual.inspect} not to #{description}"
         end
 
         def description
@@ -51,8 +51,7 @@ def needs_expected
         end
 
         def not_numeric_clause
-          return "" if numeric?
-          ", but it could not be treated as a numeric value"
+          ", but it could not be treated as a numeric value" unless numeric?
         end
       end
     end

spec/rspec/matchers/aliases_spec.rb

@@ -80,6 +80,14 @@ module RSpec
       ).with_description("a kind of Integer")
     end
 
+    specify do
+      expect(
+        a_value_between(1, 10)
+      ).to be_aliased_to(
+        be_between(1, 10)
+      ).with_description("a value between 1 and 10 (inclusive)")
+    end
+
     specify do
       expect(
         a_value_within(0.1).of(3)

spec/rspec/matchers/built_in/be_between_spec.rb

@@ -0,0 +1,74 @@
+require 'spec_helper'
+
+describe "expect(...).to be_between(min, max)" do
+  it_behaves_like "an RSpec matcher", :valid_value => (10), :invalid_value => (11) do
+    let(:matcher) { be_between(1, 10) }
+  end
+
+  it "passes if target is between min and max" do
+    expect(10).to be_between(1, 10)
+  end
+
+  it "fails if target is not between min and max" do
+    expect {
+      # It does not go to 11
+      expect(11).to be_between(1, 10)
+    }.to fail_with("expected 11 to be between 1 and 10 (inclusive)")
+  end
+
+  it 'works with strings' do
+    expect("baz").to be_between("bar", "foo")
+    expect {
+      expect("foo").to be_between("bar", "baz")
+    }.to fail_with("expected \"foo\" to be between \"bar\" and \"baz\" (inclusive)")
+  end
+
+  it 'works with other Comparable objects' do
+    class SizeMatters
+      include Comparable
+      attr :str
+      def <=>(other)
+        str.size <=> other.str.size
+      end
+      def initialize(str)
+        @str = str
+      end
+      def inspect
+        @str
+      end
+    end
+    expect(SizeMatters.new("--")).to be_between(SizeMatters.new("-"), SizeMatters.new("---"))
+    expect {
+      expect(SizeMatters.new("---")).to be_between(SizeMatters.new("-"), SizeMatters.new("--"))
+    }.to fail_with("expected --- to be between - and -- (inclusive)")
+  end
+end
+
+describe "expect(...).not_to be_between(min, max)" do
+  it "passes if target is not between min and max" do
+    expect(11).not_to be_between(1, 10)
+  end
+
+  it "fails if target is between min and max" do
+    expect {
+      expect(10).not_to be_between(1, 10)
+    }.to fail_with("expected 10 not to be between 1 and 10 (inclusive)")
+  end
+end
+
+describe "composing with other matchers" do
+  it "passes when the matchers both match" do
+    expect([0.1, 2]).to include(a_value_between(2, 4), an_instance_of(Float))
+  end
+
+  it "provides a description" do
+    description = include(a_value_between(2, 4), an_instance_of(Float)).description
+    expect(description).to eq("include (a value between 2 and 4 (inclusive)) and (an instance of Float)")
+  end
+
+  it "fails with a clear error message when the matchers do not match" do
+    expect {
+      expect([0.1, 1]).to include(a_value_between(2, 4), an_instance_of(Float))
+    }.to fail_with("expected [0.1, 1] to include (a value between 2 and 4 (inclusive)) and (an instance of Float)")
+  end
+end

spec/rspec/matchers/description_generation_spec.rb

@@ -45,9 +45,20 @@
     expect(RSpec::Matchers.generated_description).to eq "should be > 3"
   end
 
+  it "expect(...).to be between min and max" do
+    expect(10).to be_between(0, 10)
+    expect(RSpec::Matchers.generated_description).to eq "should be between 0 and 10 (inclusive)"
+  end
+
   it "expect(...).to be predicate arg1, arg2 and arg3" do
-    expect(5.0).to be_between(0,10)
-    expect(RSpec::Matchers.generated_description).to eq "should be between 0 and 10"
+    class Parent; end
+    class Child < Parent
+      def child_of?(*parents)
+        parents.all? { |parent| self.is_a?(parent) }
+      end
+    end
+    expect(Child.new).to be_a_child_of(Parent, Object)
+    expect(RSpec::Matchers.generated_description).to eq "should be a child of Parent and Object"
   end
 
   it "expect(...).to equal" do