gerhobbelt / aster-squery

Replace nodes with CSS-like selectors in aster.

aster-squery

Replace nodes with CSS-like selectors in aster.

Allows to use CSS-style selectors for finding nodes and replacing them with results of corresponding handlers.

Uses grasp-squery behind the scenes, so check out official documentation for syntax details.

Usage

First, install aster-squery as a development dependency:

npm install --save-dev aster-squery

Then, add it to your build script:

var aster = require('aster');
var squery = require('aster-squery');

aster.src('src/**/*.js')
.map(squery({
  'if[then=return][else=return]': function (node) {
    return {
        type: 'ReturnStatement',
        argument: {
            type: 'ConditionalExpression',
            test: node.test,
            consequent: node.consequent.argument,
            alternate: node.alternate.argument
        }
    };
  }
  // , ...
}))
.map(aster.dest('dist'))
.subscribe(aster.runner);

can be also written as:

var aster = require('aster');
var equery = require('aster-equery');

aster.src('src/**/*.js')
.map(equery({
  'if[then=return][else=return]': 'return <%= test %> ? <%= consequent.argument %> : <%= alternate.argument %>'
  // , ...
}))
.map(aster.dest('dist'))
.subscribe(aster.runner);

API

squery(mappings)

mappings

Type: {pattern: handler}

Replacement mappings.

pattern

Type: String

CSS-style node selector.

handler (option 1: callback)

Type: Function(node, named)

Callback to be called on each found match. It will get two arguments - matched node object and hashmap of named subpatterns.

handler (option 2: template)

Type: String

estemplate string to be used for generating AST.

License

MIT License