spec/util_strbitop_spec.lua
author Kim Alvefur <zash@zash.se>
Sat, 23 Mar 2024 20:48:19 +0100
changeset 13465 c673ff1075bd
parent 13434 1a5e3cf037f6
permissions -rw-r--r--
mod_posix: Move everything to util.startup This allows greater control over the order of events. Notably, the internal ordering between daemonization, initialization of libunbound and setup of signal handling is sensitive. libunbound starts a separate thread for processing DNS requests. If this thread is started before signal handling has been set up, it will not inherit the signal handlers and instead behave as it would have before signal handlers were set up, i.e. cause the whole process to immediately exit. libunbound is usually initialized on the first DNS request, usually triggered by an outgoing s2s connection attempt. If daemonization happens before signals have been set up, signals may not be processed at all.

local strbitop = require "util.strbitop";
describe("util.strbitop", function ()
	describe("sand()", function ()
		it("works", function ()
			assert.equal(string.rep("Aa", 100), strbitop.sand(string.rep("a", 200), "Aa"));
		end);
		it("returns empty string if first argument is empty", function ()
			assert.equal("", strbitop.sand("", ""));
			assert.equal("", strbitop.sand("", "key"));
		end);
		it("returns initial string if key is empty", function ()
			assert.equal("hello", strbitop.sand("hello", ""));
		end);
	end);

	describe("sor()", function ()
		it("works", function ()
			assert.equal(string.rep("a", 200), strbitop.sor(string.rep("Aa", 100), "a"));
		end);
		it("returns empty string if first argument is empty", function ()
			assert.equal("", strbitop.sor("", ""));
			assert.equal("", strbitop.sor("", "key"));
		end);
		it("returns initial string if key is empty", function ()
			assert.equal("hello", strbitop.sor("hello", ""));
		end);
	end);

	describe("sxor()", function ()
		it("works", function ()
			assert.equal(string.rep("Aa", 100), strbitop.sxor(string.rep("a", 200), " \0"));
		end);
		it("returns empty string if first argument is empty", function ()
			assert.equal("", strbitop.sxor("", ""));
			assert.equal("", strbitop.sxor("", "key"));
		end);
		it("returns initial string if key is empty", function ()
			assert.equal("hello", strbitop.sxor("hello", ""));
		end);
	end);

	describe("common_prefix_bits()", function ()
		local function B(s)
			assert(#s%8==0, "Invalid test input: B(s): s should be a multiple of 8 bits in length");
			local byte = 0;
			local out_str = {};
			for i = 1, #s do
				local bit_ascii = s:byte(i);
				if bit_ascii == 49 then -- '1'
					byte = byte + 2^((7-(i-1))%8);
				elseif bit_ascii ~= 48 then
					error("Invalid test input: B(s): s should contain only '0' or '1' characters");
				end
				if (i-1)%8 == 7 then
					table.insert(out_str, string.char(byte));
					byte = 0;
				end
			end
			return table.concat(out_str);
		end

		local _cpb = strbitop.common_prefix_bits;
		local function test(a, b)
			local Ba, Bb = B(a), B(b);
			local ret1 = _cpb(Ba, Bb);
			local ret2 = _cpb(Bb, Ba);
			assert(ret1 == ret2, ("parameter order should not make a difference to the result (%s, %s) = %d, reversed = %d"):format(a, b, ret1, ret2));
			return ret1;
		end

		it("works on single bytes", function ()
			assert.equal(0, test("00000000", "11111111"));
			assert.equal(1, test("10000000", "11111111"));
			assert.equal(0, test("01000000", "11111111"));
			assert.equal(0, test("01000000", "11111111"));
			assert.equal(8, test("11111111", "11111111"));
		end);

		it("works on multiple bytes", function ()
			for i = 0, 16 do
				assert.equal(i, test(string.rep("1", i)..string.rep("0", 16-i), "1111111111111111"));
			end
		end);
	end);
end);