index.js
function findDA (source, lineNumber) {
  for (var i = 0; i < source.length; i++) {
    var da = source[i]
    if (da.lineNumber === lineNumber) {
      return da
    }
  }
  return null
}
function findDA (source, lineNumber) {
  for (var i = 0; i < source.length; i++) {
    var da = source[i]
    if (da.lineNumber === lineNumber) {
      return da
    }
  }
  return null
}
function findDA ( source , lineNumber ) { for ( var i = 0 ; i < source . length ; i ++ ) { var da = source [ i ] if ( da . lineNumber === lineNumber ) { return da } } return null }
Find an existing DA record

@param {DA[]}     source
@param {number} lineNumber

@returns {DA|null}
Find an existing DA record