[v1.5.4] [Moodle 4.1.13] JS console error: "chartjs-lazy.js:1 Invalid scale configuration for scale" (xAxes + yAxes)

[danowar2k]

Moodle Version in use
Moodle 4.1.13

** Plugin Version **
v1.5.4

Describe the bug
On the page mod/pdfannotator/view.php?id=31156&action=statistic (as an example), the graph statistic throws console errors (unknown yet if that affects anything). See the screenshot.

Going into the code, it originates in shared/statistics.js. See

moodle-mod_pdfannotator/shared/statistic.js

Lines 118 to 132 in bea2d65

	scales: {
	xAxes: [{
	stacked: true,
	ticks: {
	autoSkip: false
	}
	}],
	yAxes: [{
	ticks: {
	beginAtZero: true,
	precision: 0,
	max: maxValue + 2
	}
	}]
	},

.
The xAxes/yAxes scales configuration used to call Moodle's chartjs library is an array of a single object. Moodle's chartjs library validates the scales config to ensure it's an object, see https://github.com/moodle/moodle/blob/ab5692acdf1f9a2b3cf06986f49b951558793f38/lib/amd/src/chartjs-lazy.js#L7282-L7289. (master, Moodle 4.1.13 is the same).

The simple solution seems to be to change the scales config from an array of a single object to just a single object. At least this way the error vanishes from the console log.

To Reproduce
Steps to reproduce the behavior:

1. View mod/pdfannotator/view.php?id=REPLACE_WITH_ID&action=statistic
2. Open the console log, there is the error

Expected behavior
No console error. As the scale config is ignored, there should probably be differences in the scales.

Screenshots

Desktop (please complete the following information):

• OS: Windows 10
• Browser Chrome
• Version 131.0.6778.205