Conditional expressions [[ ... ]] && work if used with yamal block literals "|"

Build Environment
11

Lets reset the conversation :slight_smile: and simplify things.

First, as you point out, the code below is NOT legal yamal:

- [[ "B" == "B" ]] && echo "B does equal B"

And the error that yaml-online-parser.appspot.com is as you say the &'s

ERROR:

while scanning an anchor
  in "<unicode string>", line 1, column 20:
    - [[ "B" == "B" ]] && echo "B does equal B"
                       ^
expected alphabetic or numeric character, but found '&'
  in "<unicode string>", line 1, column 21:
    - [[ "B" == "B" ]] && echo "B does equal B"
                        ^

But when you introduce a block literal it is legal yamal and legal bash and circleci works just fine.
Here is the github project and here is the test on circleci:

test:
  pre:
    - |
      [[ "B" == "B" ]] && echo "B does equal B"

So the above obviously works is this expected or not?