Leave that off. We are overriding it anyway so eliminate that as a potential source of confusion.
Partially because the specific syntax will be slightly different from one binding to the next. Some use “JS|blah blah blah”, others use “JS: blah blah blah” and so on.
Pay close attention to Pali’s post 9 above. Are you running a recent SNAPSHOT? If not this feature of the transform doesn’t exist in your version of OH.
I think you mean instead JS:| blah blah vs older JS(| blah blah)?
Modbus binding for example used to support only latter (older) syntax for transformations, but now supports both. But I do expect that pipe | needs to be there for JS transformation to understand that user is specifying inline transformation instead of filename. Bindings are merely responsible of parsing the transformation to use (JS) and parameter to send to the transformation. Some bindings also support “chaining” of transformations.
Latest follows the SNAPSHOTS. The docs are only baselined and frozen for a full release. So right now we have 3.1 release and 3.2 SNAPSHOTs in the docs.