bug(table): index out of range with varying row widths in StyleFunc

[bashbunni]

if you do a conditional check in StyleFunc and the table rows have varying lengths, you'll get an index out of range error. This also happens if you don't do a check for row == HeaderRow.

func TestTableWithStyleFuncLinks(t *testing.T) {
	headers := []string{"Package", "Version", "Link"}
	data := [][]string{
		{"sourcegit", "0.19", "https://aur.archlinux.org/packages/sourcegit-bin", ""},
                {},
		{"Welcome", "いらっしゃいませ", "مرحباً"},
		{"Goodbye", "さようなら", "مع السلامة"},
	}
	table := New().
		Headers(headers...).
		Rows(data...).
		StyleFunc(func(row, col int) lipgloss.Style {
			if row == HeaderRow {
				return lipgloss.NewStyle()
			}
			if strings.Contains(data[row][col], "https://") {
				return lipgloss.NewStyle().Foreground(lipgloss.Color("#31BB71"))
			}
			return lipgloss.NewStyle()
		}).
		Width(60).
		Wrap(true)
		golden.RequireEqual(t, []byte(table.String()))
}

[andreynering]

I'm not sure how we could help the user to avoid panics here. In theory, this is something the user has to address:

if i < len(data) && j < len(data[i]) {
        // do something
} else {
        // do nothing, index would overflow
}

To improve, we might have to consider a whole different function signature to styleFunc, but then it'd be a breaking change.

[bashbunni]

I wonder if we should maybe fill data with empty content to have an equal # of columns for all rows. We render empty cells anyway in the table.

e.g.

	data := [][]string{
		{"sourcegit", "0.19", "https://aur.archlinux.org/packages/sourcegit-bin", ""},
                {},
		{"Welcome", "いらっしゃいませ", "مرحباً"},
		{"Goodbye", "さようなら", "مع السلامة"},
	}

becomes

	data := [][]string{
		{"sourcegit", "0.19", "https://aur.archlinux.org/packages/sourcegit-bin", ""},
                {"", "", "", ""},
		{"Welcome", "いらっしゃいませ", "مرحباً", ""},
		{"Goodbye", "さようなら", "مع السلامة", ""},
	}

💭

[andreynering]

We would be mutating the data the user is providing. I don't think it's a good idea.

[bashbunni]

@andreynering ah true! We can keep it in the back of our minds then

[bashbunni]

I'm going to make this a discussion until we decide on a solution. Will keep it labelled as a bug though.