@qnighy/marshal

@qnighy/marshal

Parses data exported by Ruby's Marshal.dump.

Quickstart

npm install --save @qnighy/marshal
# OR
yarn add @qnighy/marshal

import * as Marshal from "@qnighy/marshal";
// OR
const Marshal = require("@qnighy/marshal");

const buf = Buffer.from(
  [
    4, 8, 123, 7, 58, 9, 110, 97, 109, 101,
    73, 34, 8, 102, 111, 111, 6, 58, 6, 69,
    84, 58, 12, 110, 117, 109, 98, 101, 114, 115,
    91, 8, 105, 6, 105, 7, 105, 8,
  ]
);
const data = Marshal.parse(buf);
// => { name: 'foo', numbers: [ 1, 2, 3 ] }

API

function parse

Parses a data exported by Ruby's Marshal.load.

• Parameters
  • buf: Buffer
    a binary data to parse
• Returns
  • unknown
    the decoded value
• Throws
  • MarshalError
    when the data contains an invalid format.

class MarshalError

An exception raised when loadMarshal encountered an invalid format.

• Superclass
  • Error

Notes on conversion

Ruby's value structure doesn't correspond to that of JavaScript. Here is how @qnighy/marshal converts values:

• Fixnums, Bignums, and Floats are all converted to numbers.
• Strings and Symbols are all converted to strings.
  • Encoding specifications are ignored and all strings are interpreted in UTF-8.
  • Bytes invalid as UTF-8 are replaced by U+FFFD.
• Hashes are converted to objects.
  • Only keys that are a number or a string (including ones that were Symbols) are picked.
  • Any other keys (nil, [1, 2], etc.) are discarded.
  • If it has default value, it's replaced as the special __ruby_default key.
• Structs are converted to objects.
• Regexps are converted to RegExps.
  • Flags are ignored in the current version.
  • Syntax errors in new RegExp(...) are propagated in the current version.
• Plain Objects are converted to empty objects.
• Classes and modules are converted to empty objects.
• All instance variables and class information are discarded. Even instances of subclasses of String, Array, Hash, and Regexp will be recognized the same as instances of their base classes.
• If two occurrences of objects pointed to the identical object in Ruby, they will be identical in JS.
  • This rule doesn't apply when the object was parsed as a primitive value in JS. Examples include Bignum, Float, and String.
• Cyclic references are kept as-is.

License

MIT