return function()
	local base64 = require(script.Parent.base64)

	it("should encode and decode", function()
		local function try(str, expected)
			local encoded = base64.encode(str)
			expect(encoded).to.equal(expected)
			expect(base64.decode(encoded)).to.equal(str)
		end

		try("Man", "TWFu")
		try("Ma", "TWE=")
		try("M", "TQ==")
		try("ManM", "TWFuTQ==")
		try(
			[[Man is distinguished, not only by his reason, but by this ]]..
			[[singular passion from other animals, which is a lust of the ]]..
			[[mind, that by a perseverance of delight in the continued and ]]..
			[[indefatigable generation of knowledge, exceeds the short ]]..
			[[vehemence of any carnal pleasure.]],
			[[TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sI]]..
			[[GJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYW]]..
			[[xzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJ]]..
			[[zZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGludWVkIGFuZCBpbmRl]]..
			[[ZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdlLCBleGNlZWRzIHRoZ]]..
			[[SBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=]]
		)
	end)
end