node_modules/prismjs/tests/languages/twig/boolean_feature.test

{{ null }}
{{- true -}}
{{ false }}

----------------------------------------------------

[
	["tag", [
		["ld", [["punctuation", "{{"]]],
		["boolean", "null"],
		["rd", [["punctuation", "}}"]]]
	]],
	["tag", [
		["ld", [["punctuation", "{{-"]]],
		["boolean", "true"],
		["rd", [["punctuation", "-}}"]]]
	]],
	["tag", [
		["ld", [["punctuation", "{{"]]],
		["boolean", "false"],
		["rd", [["punctuation", "}}"]]]
	]]
]

----------------------------------------------------

Checks for booleans and null.