ast-test

Test source tree on passing some condition.

Use

$ npm install --save ast-test

var parse = require('esprima').parse;
var test = require('ast-test');

//catch all `foo` assignments
var rule = {
	AssignmentExpression: function (node) {
		if (node.operator !== '=') return false;
		return node.left.name === 'foo';
	}
};

test(parse('foo = 1;').body[0], rule) //true
test(parse('var foo = 1;').body[0], rule) //false

API

test(Node, testRules) → Boolean

Test whether node passes test rules passed. testRules is an object containing node types as keys and testing functions as values. Matched nodes are tested with according testing functions, and if matched none — test returns false. You can declare node supertypes to match, in that case they will be checked beforehead.

var rule = {
	Expression: function (node) {
		return true;
	},
	AssignmentExpression: function (node) {
		if (node.operator !== '=') return false;
		return node.left.name === 'foo';
	}
};

test(parse('foo = 1;').body[0].expression, rule); //true
test(parse('bar = 1;').body[0].expression, rule); //false
test(parse('var foo = 1;').body[0], rule); //false