Spacer Block: Collapse when using inspector control

[jasmussen]

If I add the following in theme.json,

		"spacing": {
			"customSpacingSize": true,
			"spacingScale": {
				"increment": 1.5,
				"mediumStep": 1.5,
				"operator": "*",
				"steps": 7,
				"unit": "rem"
			},
			"spacingSizes": [],
			"units": [
				"%",
				"px",
				"em",
				"rem",
				"vh",
				"vw"
			]
		},

then the spacer block collapses to a single pixel if using the inspector control:

Notably if I remove this line, it works with the new stepped control:

			"spacingSizes": [],

As shown here:

It would seem that the crash happens when an empty array is passed to the spacing sizes. Is this incorrect theme.json usage, or should the control be able to handle it?

[carolinan]

What was the expected result from adding "spacingSizes": [],?

[jasmussen]

To be honest, I don't know as I didn't work on the theme in question (called "Fewer") and I think I'll suggest removing that clause to improve the theme with spacing presets. It's an older block theme so it could have had an intended effect a while back which is no longer relevant.

[carolinan]

🤔 It doesn't look like the intention was to remove the option since the custom spacing scale is added.

[grantgeard]

I am encountering the same bug when settings.spacing.spacingScale.steps is equal to zero. In this case, my intent is to remove the spacing scale option and this did work up until WordPress v6.3.0, so far as I know. Removing this setting adds the scale back to the UI and fixes the issue.

There is a similar bug with block gap as reported in issue #45827.