I think I misunderstand. How would that help my insert statement?You would get INSERT INTO mytable VALUES ($ _javascript_ with a lot of unescaped characters like /n " // etc. $);
Tom Lane provided the relevant syntax link, though if you supply an actual, shortened, example someone might show exactly what this all means for you - or how you'd need to tweak your text to make it work.
$$ { "key1": "value",
"key2": "value" } $$
Will be inserted as-is, explicit newlines and all. Likewise,
$$ { "key1": "value", \n "key2": "value" } $$
will be inserted without any newlines and with a literal "\n" in the middle of the text.
Unlike single-quote literals there is no alternate "E" form of dollar-quoting that will cause the \n to be interpreted as a newline. In practice its absence doesn't seem missed.
David J.