bar plot and grouped unused levels buggy

[moapy]

Unused levels seems to break grouped bar charts.

I'm trying to show right skewed likert data that is also grouped.

My Likert summary looks fine (generated using likert::likert(dat, grouping = dat$group))

Group	Item	Strongly Disagree	Disagree	Slightly Disagree	Slightly Agree	Agree	Strongly Agree
Group 1	Item 1	0	0	0	0	20	80
Group 1	Item 2	0	0	0	0	20	80
Group 2	Item 1	0	0	0	10	40	50
Group 2	Item 2	0	0	0	20	60	20

However, this will not plot: plot(likert::likert(dat, grouping = dat$group)

Error in seq_len(n) : argument must be coercible to non-negative integer

I'm pretty sure it relates to the grouping/and or the skew in the data, as I **can generate a plot for each Group individually** no worries, or if **I artificially create a new row in my dataset and add a single Strongly Disagree to each item and group, then it works fine,** producing the grouped plot with both items?!?!

This o**nly occurs for the bar type**, it doesn't happen if I set the density plot option plot(q_ab.s, type = "density")

I've also noticed that if I produce any plot with likert() that has an unused level (common with the small samples I work with), the formatting is totally weird, with a big empty space at the top. I wonder if this is related?