rocambole-linebreak

Helpers to manipulate rocambole LineBreak tokens.

Used mainly by esformatter and its plugins.

Allowed values

• positive integer (1 till 99): "add or keep [n] line breaks".
• -1: keep original line breaks.
• ">2": add linebreaks until it's over 2.
• ">=1": add line breaks until it's equal or greater than 1.
• "<2": remove linebreaks until it's smaller than 2.
• "<=1": remove/add line breaks until it's smaller or equal to 1.

API

var br = require('rocambole-linebreak');

setOptions(opts)

setOptions is just a way to store some constants so later on the limit/limitBefore/limitAfter you can reference the values by Id.

setOptions({
  // sets "value" used by `LineBreak` tokens (defaults to `"\n"`)
  value: '\n',

  // values inside "before" are used by `limitBefore`
  before: {
    // setting to `0` will remove all line breaks before the token
    parenthesis: 0
  },

  // values inside "after" are used by `limitAfter`
  after: {
    // setting to `1` will add/keep a single `LineBreak` after the token
    parenthesis: 1
  }
});

Important: calling this method will override all the options.

limitBefore(token, typeOrValue)

limits the amount of LineBreak before a given token.

// remove all line breaks before `node.startToken`
limitBefore(node.startToken, 0);
// add/keep 2 line breaks before `node.startToken`
limitBefore(node.startToken, 2);
// add/keep more than 1 line break
limitBefore(node.startToken, '>1');
// keep 2 line breaks or more
limitBefore(node.startToken, '>=2');
// keep less than 3 line breaks
limitBefore(node.startToken, '<3');
// will use value stored on `setOptions` for `before.parenthesis`
limitBefore(node.startToken, 'parenthesis');
// values smaller than zero are ignored (this won't change anything)
limitBefore(node.startToken, -1);

limitAfter(token, typeOrValue)

limits the amount of LineBreak after a given token.

// remove all line breaks after `node.startToken`
limitAfter(node.startToken, 0);
// add/keep 1 line break after `node.startToken`
limitAfter(node.startToken, 1);
// add/keep more than 1 line break
limitAfter(node.startToken, '>1');
// keep 2 line breaks or more
limitAfter(node.startToken, '>=2');
// keep less than 3 line breaks
limitAfter(node.startToken, '<3');
// will use value stored on `setOptions` for `after.parenthesis`
limitAfter(node.startToken, 'parenthesis');
// values smaller than zero are ignored (this won't change anything)
limitAfter(node.startToken, -1);

limit(token, typeOrValue)

limits the amount of LineBreak around a given token.

// add/keep 1 line break before and after `node.startToken`
limit(node.startToken, 1);

// it's just an alias to
limitBefore(node.startToken, 1);
limitAfter(node.startToken, 1);

limitBeforeEndOfFile(ast[, typeOrValue])

limits the amount of line breaks at the end of the AST.

// at least one line break at the end of the file
limitBeforeEndOfFile(ast, 1);
// if you don't pass the `typeOrValue` it will use "EndOfFile" as the type
limitBeforeEndOfFile(ast);

expectedBefore(type)

reads value stored during setOptions for a given type, or returns -1 if not found.

assert( expectedBefore('parenthesis') === 0 );

expectedAfter(type)

reads value stored during setOptions for a given type, or returns -1 if not found.

assert( expectedAfter('parenthesis') === 1 );

Debug

This module uses debug internally. To make it easier to identify what is wrong we sometimes run the esformatter tests with a DEBUG flag, like:

DEBUG=rocambole:br:* npm test

License

Released under the MIT License