parallax/jsPDF · error · Error

Invalid arguments passed to jsPDF.context2d.fillText

Error message

Invalid arguments passed to jsPDF.context2d.fillText

What it means

fillText requires the text argument to be a string and x/y to be finite numbers; the guard is isNaN(x) || isNaN(y) || typeof text !== 'string'. maxWidth is optional — an NaN maxWidth is silently coerced to undefined, so it never triggers this error. Validation runs before the fill-transparency check.

Source

Thrown at src/modules/context2d.js:1329

  var isStrokeTransparent = function() {
    return Boolean(this.ctx.isStrokeTransparent || this.globalAlpha == 0);
  };

  /**
   * Draws "filled" text on the canvas
   *
   * @name fillText
   * @function
   * @param text {String} Specifies the text that will be written on the canvas
   * @param x {Number} The x coordinate where to start painting the text (relative to the canvas)
   * @param y {Number} The y coordinate where to start painting the text (relative to the canvas)
   * @param maxWidth {Number} Optional. The maximum allowed width of the text, in pixels
   * @description The fillText() method draws filled text on the canvas. The default color of the text is black.
   */
  Context2D.prototype.fillText = function(text, x, y, maxWidth) {
    if (isNaN(x) || isNaN(y) || typeof text !== "string") {
      console.error("jsPDF.context2d.fillText: Invalid arguments", arguments);
      throw new Error("Invalid arguments passed to jsPDF.context2d.fillText");
    }
    maxWidth = isNaN(maxWidth) ? undefined : maxWidth;
    if (isFillTransparent.call(this)) {
      return;
    }

    var degs = rad2deg(this.ctx.transform.rotation);

    // We only use X axis as scale hint
    var scale = this.ctx.transform.scaleX;

    putText.call(this, {
      text: text,
      x: x,
      y: y,
      scale: scale,
      angle: degs,
      align: this.textAlign,

View on GitHub (pinned to a3930ce03a)

Solutions

Coerce text with String(...) and validate x/y with Number.isFinite before calling.
Guard the whole call: if (typeof text === 'string' && Number.isFinite(+x) && Number.isFinite(+y)) ctx.fillText(text, +x, +y);
Check argument order — text comes first, then x, then y, then optional maxWidth.

Example fix

// before
ctx.fillText(score, x, y); // score is a number -> throws [106]

// after
if (Number.isFinite(x) && Number.isFinite(y)) ctx.fillText(String(score), x, y);

Defensive patterns

Strategy: validation

Validate before calling

function safeFillText(ctx, text, x, y, maxWidth) {
  if (typeof text !== 'string') text = String(text);
  if (!Number.isFinite(+x) || !Number.isFinite(+y)) return;
  ctx.fillText(text, +x, +y, Number.isFinite(+maxWidth) ? +maxWidth : undefined);
}

Type guard

function isFillTextArgs(text, x, y) {
  return typeof text === 'string' && Number.isFinite(+x) && Number.isFinite(+y);
}

Try / catch

try { ctx.fillText(text, x, y); }
catch (e) { if (!/context2d.fillText/.test(e.message)) throw e; /* else stringify+retry */ }

Prevention

Always stringify dynamic values before passing as text.
Keep argument order: text, x, y, [maxWidth].
Validate coordinates at the layout boundary.

When it happens

Trigger: ctx.fillText(text, x, y) where text is a number, object, undefined, or null; x or y undefined/NaN; passing a numeric value where text was expected (e.g. argument order swapped).

Common situations: Rendering metrics or counters without String() coercion; calling fillText(value, x, y) instead of fillText(String(value), x, y); reading x/y from NaN-producing transforms.

Related errors

AI-assisted analysis of parallax/jsPDF@a3930ce03a (2026-08-13). Data as JSON: /api/errors/514108610e4fe246. Report an issue: GitHub.