Verbose alternation-in-optional error message

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased]
 ### Changed
 - [Ruby] Added subsidiary rubocop gems (RSpec/Rake/Performance), and did some initial refactoring ([#247](https://github.com/cucumber/cucumber-expressions/pull/247))
+- Additional information for alternation inside optional error message on how to fix ([#260](https://github.com/cucumber/cucumber-expressions/pull/260))
 
 ### Fixed
 - Removed repeated 'the' from error message for use of alternations inside optionals ([#252](https://github.com/cucumber/cucumber-expressions/issues/252))

dotnet/CucumberExpressions/CucumberExpressionException.cs

@@ -30,7 +30,7 @@ public CucumberExpressionException(string message, Exception innerException) : b
                 expression,
                 PointAt(current),
                 "An alternation can not be used inside an optional",
-                "You can use '\\/' to escape the '/'"
+                "If you did not mean to use an alternation you can use '\\/' to escape the '/'. Otherwise rephrase your expression or consider using a regular expression instead."
         ));
     }
 

go/errors.go

@@ -34,7 +34,7 @@ func createAlternationNotAllowedInOptional(expression string, current token) err
 		expression,
 		pointAtToken(current),
 		"An alternation can not be used inside an optional",
-		"You can use '\\/' to escape the '/'",
+		"If you did not mean to use an alternation you can use '\\/' to escape the '/'. Otherwise rephrase your expression or consider using a regular expression instead.",
 	))
 }
 

java/src/main/java/io/cucumber/cucumberexpressions/CucumberExpressionException.java

@@ -34,7 +34,7 @@ static CucumberExpressionException createAlternationNotAllowedInOptional(String
                 expression,
                 pointAt(current),
                 "An alternation can not be used inside an optional",
-                "You can use '\\/' to escape the '/'"
+                "If you did not mean to use an alternation you can use '\\/' to escape the '/'. Otherwise rephrase your expression or consider using a regular expression instead."
         ));
     }
 

javascript/src/Errors.ts

@@ -115,7 +115,7 @@ export function createAlternationNotAllowedInOptional(expression: string, curren
       expression,
       pointAtLocated(current),
       'An alternation can not be used inside an optional',
-      "You can use '\\/' to escape the '/'"
+      "If you did not mean to use an alternation you can use '\\/' to escape the '/'. Otherwise rephrase your expression or consider using a regular expression instead."
     )
   )
 }

python/cucumber_expressions/errors.py

@@ -140,7 +140,10 @@ def __init__(self, expression: str, current):
                 expression=expression,
                 pointer=point_at_located(current),
                 problem="An alternation can not be used inside an optional",
-                solution="You can use '\\/' to escape the '/'",
+                solution=(
+                    "If you did not mean to use an alternation you can use '\\/' to escape the '/'. "
+                    "Otherwise rephrase your expression or consider using a regular expression instead."
+                ),
             )
         )
 

ruby/lib/cucumber/cucumber_expressions/errors.rb

@@ -158,7 +158,7 @@ def initialize(expression, current)
             expression,
             point_at_located(current),
             'An alternation can not be used inside an optional',
-            "You can use '\\/' to escape the '/'"
+            "If you did not mean to use an alternation you can use '\\/' to escape the '/'. Otherwise rephrase your expression or consider using a regular expression instead."
           )
         )
       end

testdata/cucumber-expression/matching/does-not-allow-alternation-in-optional.yaml

@@ -7,4 +7,4 @@ exception: |-
   three( brown/black) mice
               ^
   An alternation can not be used inside an optional.
-  You can use '\/' to escape the '/'
+  If you did not mean to use an alternation you can use '\/' to escape the '/'. Otherwise rephrase your expression or consider using a regular expression instead.