Fix failure message for numericality matcher

Secondary author: Mauro George <[email protected]>

Sometimes the failure message did not always provide the reason for
failure. For instance, given this validation:

    validates :ano, numericality: { only_integer: true, greater_than_or_equal_to: 1900 }

this test:

    it { should validate_numericality_of(:ano).is_greater_than_or_equal_to(1900) }

would fail with the following:

    Did not expect errors  when ano is set to 1900.000000000001, got error:

as you can see, the failure message doesn't contain the validation
error.

In the process of making this fix, we changed how the matcher fails so
that it will so when the first submatcher fails, not the last. This
changes what the failure message looks like, but not the basic
functionality of the matcher itself.

NEWS.md

@@ -154,6 +154,9 @@
 * Fix `validate_uniqueness_of` so that it allows you to test against scoped
   attributes that are boolean columns. ([#457], [#694])
 
+* Fix failure message for `validate_numericality_of` as it sometimes didn't
+  provide the reason for failure. ([#699])
+
 ### Features
 
 * Add `on` qualifier to `permit`. This allows you to make an assertion that
@@ -196,6 +199,7 @@
 [#457]: https://github.com/thoughtbot/shoulda-matchers/pull/457
 [#694]: https://github.com/thoughtbot/shoulda-matchers/pull/694
 [#692]: https://github.com/thoughtbot/shoulda-matchers/pull/692
+[#699]: https://github.com/thoughtbot/shoulda-matchers/pull/699
 
 # 2.8.0
 

lib/shoulda/matchers/active_model/validate_numericality_of_matcher.rb

@@ -391,7 +391,7 @@ def on(context)
 
         def matches?(subject)
           @subject = subject
-          failing_submatchers.empty?
+          first_failing_submatcher.nil?
         end
 
         def description
@@ -410,12 +410,12 @@ def description
         end
 
         def failure_message
-          last_failing_submatcher.failure_message
+          first_failing_submatcher.failure_message
         end
         alias failure_message_for_should failure_message
 
         def failure_message_when_negated
-          last_failing_submatcher.failure_message_when_negated
+          first_failing_submatcher.failure_message_when_negated
         end
         alias failure_message_for_should_not failure_message_when_negated
 
@@ -450,21 +450,10 @@ def update_diff_to_compare(matcher)
           @diff_to_compare = [@diff_to_compare, matcher.diff_to_compare].max
         end
 
-        def submatchers_and_results
-          @_submatchers_and_results ||=
-            @submatchers.map do |matcher|
-              { matcher: matcher, matched: matcher.matches?(@subject) }
-            end
-        end
-
-        def failing_submatchers
-          submatchers_and_results.
-            select { |x| !x[:matched] }.
-            map { |x| x[:matcher] }
-        end
-
-        def last_failing_submatcher
-          failing_submatchers.last
+        def first_failing_submatcher
+          @_first_failing_submatcher ||= @submatchers.detect do |submatcher|
+            !submatcher.matches?(@subject)
+          end
         end
 
         def allowed_types

spec/support/unit/helpers/rails_versions.rb

@@ -20,5 +20,9 @@ def rails_4_x?
     def rails_gte_4_1?
       rails_version >= 4.1
     end
+
+    def rails_gte_4_2?
+      rails_version >= 4.2
+    end
   end
 end

spec/support/unit/matchers/fail_with_message_matcher.rb

@@ -16,7 +16,7 @@ def supports_block_expectations?
           @actual = ex.message
         end
 
-        @actual && @actual == expected
+        @actual && @actual == expected.sub(/\n\z/, '')
       end
 
       def failure_message