Function extract_scope_names

pub fn extract_scope_names(src: &str) -> Result<Scopes, ParseError>

Extracts function scopes from the given JS-like src.

The returned Vec includes the Range of the function scope, in byte offsets inside the src, and the corresponding function name. None in this case denotes a function scope for which no name could be inferred from the surrounding code, which can mostly happen for anonymous or arrow functions used as immediate callbacks.

The range includes the whole range of the function expression, including the leading function keyword, function argument parentheses and trailing brace in case there is one. The returned vector does not have a guaranteed sorting order, and is implementation dependent.

Examples

let src = "const arrowFnExpr = (a) => a; function namedFnDecl() {}";
//                arrowFnExpr -^------^  ^------namedFnDecl------^
let mut scopes: Vec<_> = js_source_scopes::extract_scope_names(src)
    .unwrap()
    .into_iter()
    .map(|res| {
        let components = res.1.map(|n| n.components().map(|c| {
            (c.text().to_string(), c.range())
        }).collect::<Vec<_>>());
        (res.0, components)
    }).collect();
scopes.sort_by_key(|s| s.0.start);

let expected = vec![
  (20..28, Some(vec![(String::from("arrowFnExpr"), Some(6..17))])),
  (30..55, Some(vec![(String::from("namedFnDecl"),Some(39..50))])),
];
assert_eq!(scopes, expected);