What causes "Invalid arguments passed to jsPDF.triangle" in parallax/jsPDF?

Pass six finite numeric coordinates plus a valid style code.

parallax/jsPDF · error · Error

Invalid arguments passed to jsPDF.triangle

Error message

Invalid arguments passed to jsPDF.triangle

What it means

Thrown by jsPDF.triangle when any of the six coordinates (x1,y1,x2,y2,x3,y3) is NaN or the style is invalid. All coordinates must be finite numbers; style must pass isValidStyle (undefined, null, 'S', 'D', 'F', 'DF', 'FD', 'f', 'f*', 'B', 'B*', 'n').

Source

Thrown at src/jspdf.js:4766

  API.__private__.triangle = API.triangle = function(
    x1,
    y1,
    x2,
    y2,
    x3,
    y3,
    style
  ) {
    if (
      isNaN(x1) ||
      isNaN(y1) ||
      isNaN(x2) ||
      isNaN(y2) ||
      isNaN(x3) ||
      isNaN(y3) ||
      !isValidStyle(style)
    ) {
      throw new Error("Invalid arguments passed to jsPDF.triangle");
    }
    this.lines(
      [
        [x2 - x1, y2 - y1], // vector to point 2
        [x3 - x2, y3 - y2], // vector to point 3
        [x1 - x3, y1 - y3] // closing vector back to point 1
      ],
      x1,
      y1, // start of path
      [1, 1],
      style,
      true
    );
    return this;
  };

  /**
   * Adds a rectangle with rounded corners to PDF.

View on GitHub (pinned to a3930ce03a)

Solutions

Pass six finite numeric coordinates plus a valid style code.
Map 'stroke'/'fill' to 'S'/'F' (or 'DF' for both) in your wrapper.
Default or validate each vertex property before calling.

Example fix

// before
pdf.triangle(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, 'stroke'); // invalid style
// after
pdf.triangle(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, 'S');

Defensive patterns

Strategy: validation

Validate before calling

const VALID_STYLES = [undefined, null, 'S','D','F','DF','FD','f','f*','B','B*','n'];
function safeTriangle(doc, x1,y1,x2,y2,x3,y3, style) {
  if (![x1,y1,x2,y2,x3,y3].every(Number.isFinite)) throw new Error('all vertices must be finite');
  return doc.triangle(x1,y1,x2,y2,x3,y3, VALID_STYLES.includes(style) ? style : 'S');
}

Type guard

function isValidStyle(s) { return [undefined,null,'S','D','F','DF','FD','f','f*','B','B*','n'].includes(s); }

Prevention

Validate all six vertex coordinates before calling.
Use PDF operator codes for style.
Default each vertex property in your data layer.

When it happens

Trigger: Calling triangle() with a missing vertex coordinate, a non-numeric value, or an unsupported style such as 'stroke', 'outline', or a number.

Common situations: Vertex data sourced from an object with missing properties; friendly style names used instead of PDF codes; passing only five coordinates by mistake.

Related errors

AI-assisted analysis of parallax/jsPDF@a3930ce03a (2026-08-13). Data as JSON: /api/errors/8c199d86c1fc9760. Report an issue: GitHub.