parallax/jsPDF · error · Error

Invalid arguments passed to jsPDF.context2d.transform

Error message

Invalid arguments passed to jsPDF.context2d.transform

What it means

transform validates all six matrix components (a,b,c,d,e,f) with isNaN before constructing and multiplying the matrix. Any undefined/missing/non-numeric component throws. This mirrors the HTML5 CanvasTransform.transform signature.

Source

Thrown at src/modules/context2d.js:1508

  };

  /**
   * Replaces the current transformation matrix for the drawing
   *
   * @name transform
   * @function
   * @param a {Number} Horizontal scaling
   * @param b {Number} Horizontal skewing
   * @param c {Number} Vertical skewing
   * @param d {Number} Vertical scaling
   * @param e {Number} Horizontal moving
   * @param f {Number} Vertical moving
   * @description Each object on the canvas has a current transformation matrix.<br /><br />The transform() method replaces the current transformation matrix. It multiplies the current transformation matrix with the matrix described by:<br /><br /><br /><br />a    c    e<br /><br />b    d    f<br /><br />0    0    1<br /><br />In other words, the transform() method lets you scale, rotate, move, and skew the current context.
   */
  Context2D.prototype.transform = function(a, b, c, d, e, f) {
    if (isNaN(a) || isNaN(b) || isNaN(c) || isNaN(d) || isNaN(e) || isNaN(f)) {
      console.error("jsPDF.context2d.transform: Invalid arguments", arguments);
      throw new Error("Invalid arguments passed to jsPDF.context2d.transform");
    }
    var matrix = new Matrix(a, b, c, d, e, f);
    this.ctx.transform = this.ctx.transform.multiply(matrix);
  };

  /**
   * Resets the current transform to the identity matrix. Then runs transform()
   *
   * @name setTransform
   * @function
   * @param a {Number} Horizontal scaling
   * @param b {Number} Horizontal skewing
   * @param c {Number} Vertical skewing
   * @param d {Number} Vertical scaling
   * @param e {Number} Horizontal moving
   * @param f {Number} Vertical moving
   * @description Each object on the canvas has a current transformation matrix. <br /><br />The setTransform() method resets the current transform to the identity matrix, and then runs transform() with the same arguments.<br /><br />In other words, the setTransform() method lets you scale, rotate, move, and skew the current context.
   */

View on GitHub (pinned to a3930ce03a)

Solutions

Always pass six finite numbers; default missing components to the identity (1,0,0,1,0,0).
If you have a Matrix, extract its fields (a,b,c,d,e,f) explicitly rather than passing the object.
Validate all six with Number.isFinite before calling.

Example fix

// before
ctx.transform(...matrixArray); // short array -> throws [112]

// after
const [a=1,b=0,c=0,d=1,e=0,f=0] = matrixArray.map(Number);
if ([a,b,c,d,e,f].every(Number.isFinite)) ctx.transform(a,b,c,d,e,f);

Defensive patterns

Strategy: validation

Validate before calling

function safeTransform(ctx, a, b, c, d, e, f) {
  // default to identity for missing components
  const m = [a ?? 1, b ?? 0, c ?? 0, d ?? 1, e ?? 0, f ?? 0].map(Number);
  if (!m.every(Number.isFinite)) return;
  ctx.transform(...m);
}

Type guard

function isTransformArgs(a,b,c,d,e,f) {
  return [a,b,c,d,e,f].every(v => typeof v === 'number' && Number.isFinite(v));
}

Try / catch

try { ctx.transform(a, b, c, d, e, f); }
catch (e2) { if (!/context2d.transform/.test(e2.message)) throw e2; }

Prevention

Always pass six scalar components, never a Matrix object.
When spreading an array, ensure length === 6.
Default missing components to identity values (1,0,0,1,0,0).

When it happens

Trigger: ctx.transform(a,b,c,d,e,f) with fewer than six finite numeric arguments; passing a Matrix object instead of its six components; reading components from a partially-initialized matrix.

Common situations: Confusing setTransform/transform (which take six scalars) with applying a Matrix object; spreading a short array into the call; defaulting missing components incorrectly.

Related errors

AI-assisted analysis of parallax/jsPDF@a3930ce03a (2026-08-13). Data as JSON: /api/errors/c8be8c516ba17ed8. Report an issue: GitHub.