| # is-reference |
| |
| Utility for determining whether an AST node is a reference. |
| |
| `foo` is a reference in these cases: |
| |
| ```js |
| console.log( foo ); |
| var foo; |
| function foo () {} |
| function bar ( foo ) {} |
| export { foo as x }; |
| ``` |
| |
| `foo` is *not* a reference in these cases: |
| |
| ```js |
| 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.) |
| |
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| ## Installation |
| |
| ```bash |
| npm install is-reference |
| ``` |
| |
| |
| ## Usage |
| |
| Example using [Acorn](https://github.com/ternjs/acorn) and [estree-walker](https://github.com/Rich-Harris/estree-walker): |
| |
| ```js |
| const { parse } = require( 'acorn' ); |
| const { walk } = require( 'estree-walker' ); |
| const isReference = require( '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 ( isReference( 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 |