Expression codec (grails.views.gsp.codecs.expression) seems to be ignored in deployed war file

In a fresh grails 4.0.4 application the settings of

grails:
  views:
    gsp:
      codecs:
        expression: none

seem to be ignored when deployed as a war file in a Tomcat 8.5.39. (JVM 11.0.7+10-post-Ubuntu-2ubuntu218.04)

Adding this

<head>
...
  <script>
    var foo = ${[a:23, b:42, c:666] as grails.converters.JSON};
  </script>
</head>

to the generated grails-app/views/index.gsp shows up as

var foo = {"a":23,"b":42,"c":666};

when running grails run-app or even grails prod run-app(!), but is encoded as

var foo = {&quot;a&quot;:23,&quot;b&quot;:42,&quot;c&quot;:666};

in the packaged (grails prod war) deployed war file.

The build.gradle was unmodified, except for changing

compile "org.grails.plugins:cache"

to this

compile("org.grails.plugins:cache") {
  exclude module:'groovy-all'
}

Is this a bug or am I using the codecs settings wrong? Maybe there is a plugin overwriting this settings (like here https://github.com/grails/grails-core/issues/10722) but i cannot find any other yml files. Any help is appreciated!

Solution

It works like a charm in Grails 4.0.3. Seems it is broken in Grails 4.0.4 ... Maybe the problem came with the new Groovy Page Compiler Task. The config file (aka application.yml) variable here is never used. But that's only an assumption after quick investigation with too little coffee ;-)

Workaround or my preferred way (still working in Grails 4.0.4)

Some helper TagLib like this:

import grails.converters.JSON
class FooTagLib {
    static defaultEncodeAs = [taglib:'none']
    static namespace = "foo"
    def json = { attrs, body ->
        out << raw(attrs.data as JSON)
    }
}

Usage:

var foo = <foo:json data="[a:23, b:42, c:666]"/>