[mynetx]

Fixes #15832

Since #15540, a Value wrapping null stops the modifier chain before the modifier runs, so {{ empty_field | to_json }} renders nothing instead of null. Inside a JSON template that leaves invalid JSON like { "items": }.

This adds to_json and its json alias to the null-aware modifiers list from #15782, next to bool_string.

One thing to note: the list applies to bare and missing variables too, so {{ missing | to_json }} now outputs null as well. It output nothing even before #15540, but null seems like the right answer for a JSON modifier, and it matches what #15782 did for bool_string.

🤖 Generated with Claude Code

[jasonvarga]

Thanks! Technically correct but I'm going to close this in favor of #15849.