detect global and local lexical identifiers from javascript source code
var detect = require('lexical-scope');
var fs = require('fs');
var src = fs.readFileSync(__dirname + '/src.js');
var scope = detect(src);
console.log(JSON.stringify(scope,null,2));
input:
var x = 5;
var y = 3, z = 2;
w.foo();
w = 2;
RAWR=444;
RAWR.foo();
BLARG=3;
foo(function () {
var BAR = 3;
process.nextTick(function (ZZZZZZZZZZZZ) {
console.log('beep boop');
var xyz = 4;
x += 10;
x.zzzzzz;
ZZZ=6;
});
function doom () {
}
ZZZ.foo();
});
console.log(xyz);
output:
$ node example/detect.js
{
"locals": {
"": [
"x",
"y",
"z"
],
"body.7.expression.body.7.arguments.0": [
"BAR",
"doom"
],
"body.7.expression.body.7.arguments.0.body.body.1.expression.body.1.arguments.0": [
"xyz",
"ZZZZZZZZZZZZ"
],
"body.7.expression.body.7.arguments.0.body.body.2": []
},
"globals": {
"implicit": [
"w",
"foo",
"process",
"console",
"xyz"
],
"implicitProperties": {
"w": [
"foo"
],
"foo": [
"()"
],
"process": [
"nextTick"
],
"console": [
"log"
],
"xyz": [
"*"
]
},
"exported": [
"w",
"RAWR",
"BLARG",
"ZZZ"
]
}
}
If you are using a modern browser, you can go to http://lexical-scope.forbeslindesay.co.uk/ for a live demo.
var detect = require('lexical-scope')
Return a scope
structure from a javascript source string src
.
scope.locals
maps scope name keys to an array of local variable names declared
with var
. The key name ''
refers to the top-level scope.
scope.globals.implicit
contains the global variable names that are expected to
already exist in the environment by the script.
scope.globals.explicit
contains the global variable names that are exported by
the script.
scope.globals.implicitProperties
contains the properties of global variable
names that have been used. There are two special implicit property names:
"()"
- when an implicit variable has been called"*"
- when an implicit variable has been used in a context that is not a property and not a call
With npm do:
npm install lexical-scope
MIT