parallax/jsPDF · error · Error

Invalid arguments passed to jsPDF.API.__acroform__.getBitFor

Error message

Invalid arguments passed to jsPDF.API.__acroform__.getBitForPdf

What it means

Thrown by getBitForPdf(number, bitPosition) when either argument is NaN. PDF field flags count bit positions starting at 1 (per the PDF spec), so getBitForPdf validates inputs then delegates to getBit with bitPosition-1. Exposed at jsPDF.API.__acroform__.getBitForPdf.

Source

Thrown at src/modules/acroform.js:128

var getBit = (jsPDFAPI.__acroform__.getBit = function(number, bitPosition) {
  if (isNaN(number) || isNaN(bitPosition)) {
    throw new Error(
      "Invalid arguments passed to jsPDF.API.__acroform__.getBit"
    );
  }
  return (number & (1 << bitPosition)) === 0 ? 0 : 1;
});

/*
 * Ff starts counting the bit position at 1 and not like javascript at 0
 */
var getBitForPdf = (jsPDFAPI.__acroform__.getBitForPdf = function(
  number,
  bitPosition
) {
  if (isNaN(number) || isNaN(bitPosition)) {
    throw new Error(
      "Invalid arguments passed to jsPDF.API.__acroform__.getBitForPdf"
    );
  }
  return getBit(number, bitPosition - 1);
});

var setBitForPdf = (jsPDFAPI.__acroform__.setBitForPdf = function(
  number,
  bitPosition
) {
  if (isNaN(number) || isNaN(bitPosition)) {
    throw new Error(
      "Invalid arguments passed to jsPDF.API.__acroform__.setBitForPdf"
    );
  }
  return setBit(number, bitPosition - 1);
});

View on GitHub (pinned to a3930ce03a)

Solutions

  1. Validate number and bitPosition are finite numbers (bitPosition >= 1) before calling getBitForPdf.
  2. Keep F/Ff numeric so the 'number' argument is never NaN.
  3. Prefer the high-level boolean properties, which manage positions, over raw helper calls.

Example fix

// before
var printed = jsPDF.API.__acroform__.getBitForPdf(field.F, opts.pos);

// after
var pos = Number(opts.pos);
var printed = isFinite(pos) && pos >= 1
  ? jsPDF.API.__acroform__.getBitForPdf(field.F || 0, pos)
  : 0;
Defensive patterns

Strategy: type-guard

Validate before calling

function safeGetBitForPdf(number, bitPosition) {
  number = Number(number) || 0;
  var p = Number(bitPosition);
  if (!isFinite(p) || p < 1) return 0;
  return jsPDF.API.__acroform__.getBitForPdf(number, p);
}

Type guard

function areFiniteNumbers(a, b) {
  return typeof a === 'number' && isFinite(a) &&
         typeof b === 'number' && isFinite(b) && b >= 1;
}

Try / catch

try {
  return jsPDF.API.__acroform__.getBitForPdf(val, pos);
} catch (e) {
  if (/__acroform__.getBitForPdf/.test(e.message)) return 0;
  throw e;
}

Prevention

When it happens

Trigger: Calling getBitForPdf with NaN number or position; reading a 1-based PDF flag attribute whose underlying _F/_Ff is NaN, or whose position is derived from a missing value.

Common situations: Reading AcroForm boolean getters (many use getBitForPdf internally) after the flag field was corrupted; calling the helper directly with unvalidated parameters.

Related errors

AI-assisted analysis of parallax/jsPDF@a3930ce03a (2026-08-13). Data as JSON: /api/errors/3e270c8ff719e6d1. Report an issue: GitHub.