Error when test does not contain "describe" blocks

[Dkendal]

When running the test harness with the following keymap:

vim.keymaps.set("n", "<leader>tt", "<plug>PlenaryTestFile", {})

With a test:

-- describe("desc block", function()
	it("does the thing", function()
		assert.equal(1, 2)
	end)
-- end)

This error is presented:

Uncommenting the describe block fixes the error:

describe("desc block", function()
	it("does the thing", function()
		assert.equal(1, 2)
	end)
end)