[p5.js 2.0 Beta Bug Report]: FES in 2.0 does not anticipate loading problems

[ksen0]

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

p5.js version

2.0-beta.2

Web browser and version

Chrome

Operating system

MacOSX

Steps to reproduce this

Steps:

1. Get one of the 1.x reference examples of a function to load some object in preload, ensure it runs with a working file on loading
2. Update the p5.js script to use the current p5.js 2.0 beta library
3. Try to run and the error is something related to trying to use the specific object, but the variable is undefined. Thus, the FES wraps a TypeError without clearly guiding the user to the real issue, which is that preload has not been called and the object is empty.

All loaders that might be affected:

• loadModel
• loadPixels
• loadImage
• loadShader
• loadBytes
• loadTable
• loadJSON
• loadXML
• loadStrings

Snippet:

Here are two examples in to different loader functions (code needs files to run):

• loadImage example fails on image(img, 0, 0); with TypeError: Cannot read properties of undefined (reading 'width')...
• loadModel example fails on model(shape); with TypeError: Cannot read properties of undefined (reading 'vertices')...