is-reference

Utility for determining whether an AST node is a reference.

foo is a reference in these cases:

console.log(foo);
var foo;
function foo() {}
function bar(foo) {}
export { foo as x };

foo is not a reference in these cases:

var obj = { foo: 1 };
console.log(obj.foo);
export { x as foo };

In all cases, foo is an Identifier node, but the two kinds must be treated differently for the purposes of scope analysis etc. (The examples are non-exhaustive.)

Installation

npm install is-reference

Usage

Example using Acorn and estree-walker:

import { parse } from 'acorn';
import { walk } from 'estree-walker';
import is_reference from 'is-reference';

const identifiers = [];
const references = [];

const ast = parse(`var a = b.c;`);

walk(ast, {
    enter(node, parent) {
        if (node.type === 'Identifier') identifiers.push(node);
        if (is_reference(node, parent)) references.push(node);
    }
});

identifiers.forEach(node => console.log(node.name)); // a, b, c
references.forEach(node => console.log(node.name)); // a, b

License

MIT

is-reference changelog

3.0.3

• Handle import.meta nodes (#21)
• Bump various dependencies

3.0.2

• Generate types with dts-buddy

3.0.1

• Add types export to package.json (#14)

3.0.0

• Use updated ESTree types (#11)

2.0.0

• Convert to JavaScript

1.2.1

• Relax version range for @types/estree

1.2.0

• Handle class fields (#)

1.1.4

• Disregarded imported specifiers if they differ from local specifiers

1.1.3

• Handle expressions without a Program

1.1.2

• Ignore labels in break/continue statements (#4)

1.1.1

• Prevent false positives with labeled statements

1.1.0

• Rewrite in TypeScript, add declarations

1.0.1

• Ensure isReference returns a boolean

1.0.0

• First release