Modifying the parsed Javascript AST

[MichaelTheSynthCat]

Is it possible to make changes to AST built from parsed Javascript?

Let's say that I parse a script with biome_js_parser that contains this statement:

var x = "hello" + "world";

How can I find this node and replace the "hello" + "world" with a single string literal "hello world"?

[ematipico]

I suggest to look how lint rules create code actions (check the action function).

For applying the mutation and generating the new CST, here's an example:

biome/crates/biome_service/src/file_handlers/javascript.rs

Lines 725 to 739 in be56c2e

	if let (root, Some((range, _))) =
	action.mutation.commit_with_text_range_and_edit(true)
	{
	tree = match AnyJsRoot::cast(root) {
	Some(tree) => tree,
	None => {
	return Err(WorkspaceError::RuleError(
	RuleError::ReplacedRootWithNonRootError {
	rule_name: action.rule_name.map(|(group, rule)| {
	(Cow::Borrowed(group), Cow::Borrowed(rule))
	}),
	},
	));
	}
	};