Chiles NPM | npm.io

Chiles

Wrapper around esprima to modify javascript documents.

example

Modify inline comments and add content before each comment.

const _ = require('lodash');
const chiles = require('../dist/chiles.js');

const src = `
//i1
function abc(a, b) {
  //i2
}
//i3
`;

const doc = chiles(src);

console.log(doc.repr());
console.log(doc.toString());

const newNodes = [];
doc.walkPostOrder(n => {
  if (n.type === 'Line') {
    doc.update('\n', n.range[0], n.range[0], null);
    newNodes.push(doc.insert(`// ADDED: ${n.value}`, n.range[0] - 1));
    n.setSource(`// -> (${n.value})`);
  }
});

console.log(doc.repr());
console.log(doc.toString());

_.each(newNodes, n => {
  console.log([n.getSource()]);
});

output:

[0 - 41]: Document
  [0 - 41]: Program
    [1 - 5]: Line
    [6 - 35]: FunctionDeclaration
      [15 - 18]: Identifier
      [19 - 20]: Identifier
      [22 - 23]: Identifier
      [25 - 35]: BlockStatement
        [29 - 33]: Line
    [36 - 40]: Line

//i1
function abc(a, b) {
  //i2
}
//i3

[0 - 98]: Document
  [0 - 98]: Program
    [1 - 13]: _Unknown
    [14 - 24]: Line
    [25 - 73]: FunctionDeclaration
      [34 - 37]: Identifier
      [38 - 39]: Identifier
      [41 - 42]: Identifier
      [44 - 73]: BlockStatement
        [48 - 60]: _Unknown
        [61 - 71]: Line
    [74 - 86]: _Unknown
    [87 - 97]: Line

// ADDED: i1
// -> (i1)
function abc(a, b) {
  // ADDED: i2
// -> (i2)
}
// ADDED: i3
// -> (i3)

[ '// ADDED: i1' ]
[ '// ADDED: i2' ]
[ '// ADDED: i3' ]

methods

const chiles = require('chiles');

chiles(src)

Parse the string source src with esprima, returns a single Document object which can be used to modify the original source.

Document

A document object has the following methods:

str(start, end): returns a substring from the source with the specified endpoints.

repr(): Utility function displaying all the ranges and the node types for the document.

walkPostOrder(fn): Walks through the document and executes the function fn on a node only after all its children have been visited. The function fn takes in paramters node and level.

insert(text, start, type = 'Unknown'): Inserts the text text at the index spefied by start. We may optionally specified the type of node that corresponds to the inserted text.

update(text, start, end, type = 'Unknown'): Replace a substring from the source with the specified text. Usually useful when modifying a piece of text that has not yet been claimed by a node.

WARNING: At the moment there is no checks to make sure that the range we are modifying does not belong to another node.

toString(): Obtain the current document as a string.