Merge pull request #5951 from CocoaPods/dani_validator_errors

[Validator] Inform people of .swift-version on err

CHANGELOG.md

@@ -13,6 +13,11 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
   [#5934](https://github.com/CocoaPods/CocoaPods/pull/5934)
 
 * Improve performance of PathList.read_file_system 
+* Tell users about the .swift-version file on validation failures.  
+  [Danielle Tomlinson](https://github.com/dantoml)
+  [#5951](https://github.com/CocoaPods/CocoaPods/pull/5951)
+
+* Improve performance of PathList.read_file_system  
   [Heath Borders](https://github.com/hborders)
   [#5890](https://github.com/CocoaPods/CocoaPods/issues/5890)
 

lib/cocoapods/validator.rb

@@ -142,7 +142,15 @@ module Pod
         reasons << 'all results apply only to public specs, but you can use ' \
                    '`--private` to ignore them if linting the specification for a private pod'
       end
-      reasons.to_sentence
+      if dot_swift_version.nil?
+        reasons.to_sentence + ".\n[!] The validator for Swift projects uses " \
+          'Swift 2.3 by default, if you are using a different version of ' \
+          'swift you can use a `.swift-version` file to set the version for ' \
+          "your Pod. For example to use Swift 3.0, run: \n" \
+          '    `echo "3.0" > .swift-version`'
+      else
+        reasons.to_sentence
+      end
     end
 
     #-------------------------------------------------------------------------#

spec/unit/validator_spec.rb

@@ -812,6 +812,21 @@ module Pod
         validator.results.count.should == 0
       end
 
+      it 'tells users about the .swift-version file if the validation fails' do
+        Specification.any_instance.stubs(:deployment_target).returns('9.0')
+
+        validator = test_swiftpod
+        validator.stubs(:validated?).returns(false)
+        result = Validator::Result.new(:error, 'attribute', 'message')
+        validator.stubs(:results).returns([result])
+
+        validator.failure_reason.should == "1 error.\n[!] The validator for " \
+          'Swift projects uses Swift 2.3 by default, if you are using a ' \
+          'different version of swift you can use a `.swift-version` file ' \
+          'to set the version for your Pod. For example to use Swift 3.0, ' \
+          "run: \n    `echo \"3.0\" > .swift-version`"
+      end
+
       describe '#swift_version' do
         it 'defaults to Swift 2.3' do
           validator = test_swiftpod