Read a CSV file (with optional header line) and transform it into an object array

csv_to_obj_array.js

const compose = fn1 => fn2 => val => fn2(fn1(val))

// Remove only the start and end double quotes in a string
const stripQuotes  = str => str.replace(/(^")|("$)/g,"")

// Remove commas that might occur inside names
const removeCommas = str => str.replace(/,/g,"")

const cleanTxt = compose(stripQuotes)(removeCommas)

// Reject null entries
const notNull = el => el !== null

/***********************************************************************************************************************
 * Read a CSV file (with an optional header line) and transform it into an array of objects.
 * The properties of the object are supplied in the array prop_list.  The number and order of the names in prop_list
 * must match the number and order of the columns in the CSV file
 *
 * To understand how the sequence of processing works in the following function, read the comments in numerical order
 * where 1) is at the end!
 */
const csv_to_object_array = (filename, prop_list, hasHdr) =>
  ((lineArray =>                                        // 2) Arg "lineArray" is the CSV file now as an array of lines
    (hasHdr ? (lineArray.slice(1)) : lineArray)         // 3) Optionally remove the header line
    .map(                                               // 4) For each line in the CSV file...
      line =>                                           //    "line" is the arg to the mapper function
        (line.length > 0)                               // 5) Check for an empty line
        ? line.split(/,(?=(?:(?:[^"]*"){2})*[^"]*$)/)   // 6) Split line using positive lookahead to ignore quoted commas
              .reduce(                                  // 7) Transform array of fields into new object using a...
                (acc, el, idx) =>                       // 8) Reducer function
                  (_ => acc)                            // 11) Inner fn ignores its arg value and returns the accumulator
                  (acc[prop_list[idx]] = cleanTxt(el))  // 10) Add new prop/value to acc and pass to inner, anonymous fn
                , {}                                    // 9) Accumulator starts as an empty array
              )                                         //
        : null                                          // 12) Empty lines become null (will be filtered out next)
    )                                                   //
    .filter(notNull))                                   // 13) Finally, filter accumulator to remove null entries
  )                                                     //
  ((fs.readFileSync(filename, "utf-8")).split(/\r?\n/)) // 1) Read CSV file, split into lines & pass to anonymous inner fn

// Define the names of the columns in the CSV file.  These names become the property names of the generated object
const airports_props = [
  "id", "name", "city", "country", "iata", "icao", "lat", "lng"
, "elevation", "tz", "dst", "olson_tz_name", "type", "source"
]

// Assuming you have already downloaded airports.dat from OpenFlights.org, convert this CSV files to an object array
var openflights_airports = csv_to_object_array("airports.dat", airports_props, false)