T-48 Temperature#boil_water? and Temperature#freeze_water? (#46)

README.md

@@ -244,6 +244,15 @@ Also [Ruby coersion mechanism](https://ruby-doc.org/core/Numeric.html#method-i-c
 # => -20 °C
 ```
 
+### Queries
+```ruby
+Temperature[0, :celsius].boil_water?
+# => false
+
+Temperature[0, :celsius].freeze_water?
+# => true
+```
+
 ## Versioning
 Basic Temperature follows the [Semantic Versioning](https://semver.org/) standard.
 

lib/basic_temperature/temperature.rb

@@ -549,6 +549,22 @@ def -@
       Temperature.new(-self.degrees, self.scale)
     end
 
+    ##
+    # Returns true when temperature boils water (is greater than or equal to 100 °C),
+    # false otherwise.
+    #
+    def boil_water?
+      self.to_celsius.degrees >= 100
+    end
+
+    ##
+    # Returns true when temperature freezes water (is less than or equal to 0 °C),
+    # false otherwise.
+    #
+    def freeze_water?
+      self.to_celsius.degrees <= 0
+    end
+
     # Is used by {+}[rdoc-ref:Temperature#+] and {-}[rdoc-ref:Temperature#-]
     # for {Ruby coersion mechanism}[https://ruby-doc.org/core/Numeric.html#method-i-coerce].
     def coerce(numeric) #:nodoc:

lib/basic_temperature/temperature/assertions.rb

@@ -25,7 +25,7 @@ def assert_numeric_or_temperature!(numeric_or_temperature)
       end
 
       def assert_numeric!(numeric)
-        raise_invalid_numeric unless numeric.is_a?(Numeric)
+        raise_invalid_numeric(numeric) unless numeric.is_a?(Numeric)
       end
 
       def assert_temperature(temperature)

lib/basic_temperature/temperature/errors.rb

@@ -14,9 +14,12 @@ class InvalidDegrees < StandardError; end
       # See {SCALES}[rdoc-ref:Temperature::SCALES].
       class InvalidScale < StandardError; end
 
-      # Raised when <tt>other</tt> is not a Numeric or Temperature in math operations.
+      # Raised when <tt>other</tt> is neither Numeric nor Temperature in math operations.
       class InvalidNumericOrTemperature < StandardError; end
 
+      # Raised when <tt>other</tt> is not a Numeric in math operations.
+      class InvalidNumeric < StandardError; end
+
       private
 
       def raise_initialization_arguments_error
@@ -42,6 +45,10 @@ def raise_invalid_scale_error
       def raise_invalid_numeric_or_temperature_error(numeric_or_temperature)
         raise InvalidNumericOrTemperature, "`#{numeric_or_temperature}` is neither Numeric nor Temperature."
       end
+
+      def raise_invalid_numeric(numeric)
+        raise InvalidNumeric, "`#{numeric}` is not a Numeric."
+      end
     end
   end
 end

spec/basic_temperature/temperature_spec.rb

@@ -791,8 +791,86 @@
     end
   end
 
+  describe '#boil_water?' do
+    context 'when temperature is greater than 100 °C' do
+      it 'returns true' do
+        expect(Temperature.new(101, 'celsius').boil_water?).to eq(true)
+      end
+    end
+
+    context 'when temperature is equal to 100 °C' do
+      it 'returns true' do
+        expect(Temperature.new(100, 'celsius').boil_water?).to eq(true)
+      end
+    end
+
+    context 'when tempreture is less than 100 °C' do
+      it 'returns false' do
+        expect(Temperature.new(99, 'celsius').boil_water?).to eq(false)
+      end
+    end
+
+    it 'converts temperature to celsius before comparison' do
+      expect(Temperature.new(0, 'kelvin').boil_water?).to eq(false)
+    end
+  end
+
+  describe '#freeze_water?' do
+    context 'when temperature is greater than 0 °C' do
+      it 'returns false' do
+        expect(Temperature.new(1, 'celsius').freeze_water?).to eq(false)
+      end
+    end
+
+    context 'when temperature is equal to 0 °C' do
+      it 'returns true' do
+        expect(Temperature.new(0, 'celsius').freeze_water?).to eq(true)
+      end
+    end
+
+    context 'when tempreture is less than 0 °C' do
+      it 'returns true' do
+        expect(Temperature.new(-1, 'celsius').freeze_water?).to eq(true)
+      end
+    end
+
+    it 'converts temperature to celsius before comparison' do
+      expect(Temperature.new(0, 'kelvin').freeze_water?).to eq(true)
+    end
+  end
+
+  describe '#coerce' do
+    context 'when other is a Numeric' do
+      it (
+        <<~DESCRIPTION
+          returns two elements array,
+          where first element is other converted to Temperature
+          and has the same scale as temperature,
+          second - is temperature itself
+        DESCRIPTION
+      ) do
+        temperature = Temperature.new(0, 'celsius')
+
+        coerce = temperature.coerce(10)
+
+        expect(coerce.first.degrees).to eq(10)
+        expect(coerce.first.scale).to eq('celsius')
+
+        expect(coerce.last).to eq(temperature)
+      end
+    end
+
+    context 'when other is NOT a Numeric' do
+      it 'raises Errors::InvalidNumeric' do
+        expect { Temperature.new(0, 'celsius').coerce('abc') }
+          .to raise_error(Temperature::Errors::InvalidNumeric)
+          .with_message('`abc` is not a Numeric.')
+      end
+    end
+  end
+
   describe '#inspect' do
-    context 'when scale is celcius' do
+    context 'when scale is celsius' do
       it 'returns tempeture as string in special format' do
         temperature = Temperature.new(0, 'celsius')