Begin/Rescue/End block inside of a Lambda raises Style/RedundantBegin and formatter borks it

[tadiou]

Expected behavior

coerce_input ->(value, _ctx) do
  begin
    value.nil? ? nil : JSON.parse(value)
  rescue JSON::ParserError
    raise GraphQL::CoercionError, "cannot coerce `#{value.inspect}` to Hash value"
  end
end

is valid code (when stabby syntax is preferred in config).

Actual behavior

After format it looks like this

coerce_input ->(value, _ctx) do
  
    value.nil? ? nil : JSON.parse(value)
  rescue JSON::ParserError
    raise GraphQL::CoercionError, "cannot coerce `#{value.inspect}` to Hash value"
  
end 

which is invalid as heck.

Additional Info

Ruby's major GraphQL implementation often uses lambdas in arguments, we ended up sticking a begin/rescue/end block in one (because it works).

When it's separated by braces, a la

coerce_method ->(value, _ctx) {
  begin
    value.nil? ? nil : JSON.parse(value)
  rescue JSON::ParserError
    raise GraphQL::CoercionError, "cannot coerce `#{value.inspect}` to Hash value"
  end
}

It works fine. Or if it was forced to be

coerce_input lambda(value, _ctx) do
  value.nil? ? nil : JSON.parse(value)
rescue JSON::ParseError
  raise GraphQL::CoercionError, "cannot coerce `#{value.inspect}` to Hash value"
end

Basically it tries to handle the stabby syntax in the same way that's allowed by the lambda syntax and ruby doesn't handle them the same way at all.

This exists in the same format whether it's being used as an argument or assigning the lambda to a variable.

RuboCop version

0.58.2 (using Parser 2.5.1.2, running on ruby 2.5.1 x86_64-linux)

[Drenmi]

Good catch. Will have a look at this.