File

spec/util_dbuffer_spec.lua @ 13182:c48ae06e24d6

util.datamanager: Fix indexing first item if not at the very start If the first item does not start at position 0 then the index function produces a phantom first entry covering position zero until where the real first item starts. When using the index, this would make it either appear as the first item was missing or cause an off-by-one issue with remaining items.
author Kim Alvefur <zash@zash.se>
date Mon, 10 Jul 2023 17:19:05 +0200
parent 12764:bf6d2f9fad4d
line wrap: on
line source

local dbuffer = require "util.dbuffer";
describe("util.dbuffer", function ()
	describe("#new", function ()
		it("has a constructor", function ()
			assert.Function(dbuffer.new);
		end);
		it("can be created", function ()
			assert.truthy(dbuffer.new());
			assert.truthy(dbuffer.new(1));
			assert.truthy(dbuffer.new(1024));
		end);
		it("won't create an empty buffer", function ()
			assert.falsy(dbuffer.new(0));
		end);
		it("won't create a negatively sized buffer", function ()
			assert.falsy(dbuffer.new(-1));
		end);
	end);
	describe(":write", function ()
		local b = dbuffer.new(10, 3);
		it("works", function ()
			assert.truthy(b:write("hi"));
		end);
		it("fails when the buffer is full", function ()
			local ret = b:write(" there world, this is a long piece of data");
			assert.is_falsy(ret);
		end);
		it("works when max_chunks is reached", function ()
			-- Chunks are an optimization, dbuffer should collapse chunks when needed
			for _ = 1, 8 do
				assert.truthy(b:write("!"));
			end
			assert.falsy(b:write("!")); -- Length reached
		end);
	end);

	describe(":read", function ()
		it("supports optional bytes parameter", function ()
			-- should return the frontmost chunk
			local b = dbuffer.new();
			assert.truthy(b:write("hello"));
			assert.truthy(b:write(" "));
			assert.truthy(b:write("world"));
			assert.equal("h", b:read(1));

			assert.equal("ello", b:read());
			assert.equal(" ", b:read());
			assert.equal("world", b:read());
		end);
		it("fails when there is not enough data in the buffer", function ()
			local b = dbuffer.new(12);
			b:write("hello");
			b:write(" ");
			b:write("world");
			assert.is_falsy(b:read(12));
			assert.is_falsy(b:read(13));
		end);
	end);

	describe(":read_until", function ()
		it("works", function ()
			local b = dbuffer.new();
			b:write("hello\n");
			b:write("world");
			b:write("\n");
			b:write("\n\n");
			b:write("stuff");
			b:write("more\nand more");

			assert.equal(nil, b:read_until("."));
			assert.equal(nil, b:read_until("%"));
			assert.equal("hello\n", b:read_until("\n"));
			assert.equal("world\n", b:read_until("\n"));
			assert.equal("\n", b:read_until("\n"));
			assert.equal("\n", b:read_until("\n"));
			assert.equal("stu", b:read(3));
			assert.equal("ffmore\n", b:read_until("\n"));
			assert.equal(nil, b:read_until("\n"));
			assert.equal("and more", b:read_chunk());
		end);
	end);

	describe(":discard", function ()
		local b = dbuffer.new();
		it("works", function ()
			assert.truthy(b:write("hello world"));
			assert.truthy(b:discard(6));
			assert.equal(5, b:length());
			assert.equal(5, b:len());
			assert.equal("world", b:read(5));
		end);
		it("works across chunks", function ()
			assert.truthy(b:write("hello"));
			assert.truthy(b:write(" "));
			assert.truthy(b:write("world"));
			assert.truthy(b:discard(3));
			assert.equal(8, b:length());
			assert.truthy(b:discard(3));
			assert.equal(5, b:length());
			assert.equal("world", b:read(5));
		end);
		it("can discard the entire buffer", function ()
			assert.equal(b:len(), 0);
			assert.truthy(b:write("hello world"));
			assert.truthy(b:discard(11));
			assert.equal(0, b:len());
			assert.truthy(b:write("hello world"));
			assert.truthy(b:discard(12));
			assert.equal(0, b:len());
			assert.truthy(b:write("hello world"));
			assert.truthy(b:discard(128));
			assert.equal(0, b:len());
		end);
		it("works on an empty buffer", function ()
			assert.truthy(dbuffer.new():discard());
			assert.truthy(dbuffer.new():discard(0));
			assert.truthy(dbuffer.new():discard(1));
		end);
	end);

	describe(":collapse()", function ()
		it("works", function ()
			local b = dbuffer.new();
			b:write("hello");
			b:write(" ");
			b:write("world");
			b:collapse(6);
			local ret, bytes = b:read_chunk();
			assert.equal("hello ", ret);
			assert.equal(6, bytes);
		end);
		it("works on an empty buffer", function ()
			local b = dbuffer.new();
			b:collapse();
		end);
	end);

	describe(":sub", function ()
		-- Helper function to compare buffer:sub() with string:sub()
		local s = "hello world";
		local function test_sub(b, x, y)
			local string_result, buffer_result = s:sub(x, y), b:sub(x, y);
			assert.equals(string_result, buffer_result, ("buffer:sub(%d, %s) does not match string:sub()"):format(x, y and ("%d"):format(y) or "nil"));
		end

		it("works", function ()
			local b = dbuffer.new();
			assert.truthy(b:write("hello world"));
			assert.equals("hello", b:sub(1, 5));
		end);

		it("works after discard", function ()
			local b = dbuffer.new(256);
			assert.truthy(b:write("foobar"));
			assert.equals("foobar", b:sub(1, 6));
			assert.truthy(b:discard(3)); -- consume "foo"
			assert.equals("bar", b:sub(1, 3));
		end);

		it("supports optional end parameter", function ()
			local b = dbuffer.new();
			assert.truthy(b:write("hello world"));
			assert.equals("hello world", b:sub(1));
			assert.equals("world", b:sub(-5));
		end);

		it("is equivalent to string:sub", function ()
			local b = dbuffer.new(11);
			assert.truthy(b:write(s));
			for i = -13, 13 do
				for j = -13, 13 do
					test_sub(b, i, j);
				end
			end
		end);

		it("works on an empty buffer", function ()
			local b = dbuffer.new();
			assert.equal("", b:sub(1, 12));
		end);
	end);

	describe(":byte", function ()
		-- Helper function to compare buffer:byte() with string:byte()
		local s = "hello world"
		local function test_byte(b, x, y)
			local string_result, buffer_result = {s:byte(x, y)}, {b:byte(x, y)};
			assert.same(
				string_result,
				buffer_result,
				("buffer:byte(%s, %s) does not match string:byte()"):format(x and ("%d"):format(x) or "nil", y and ("%d"):format(y) or "nil")
			);
		end

		it("is equivalent to string:byte", function ()
			local b = dbuffer.new(11);
			assert.truthy(b:write(s));
			test_byte(b, 1);
			test_byte(b, 3);
			test_byte(b, -1);
			test_byte(b, -3);
			test_byte(b, nil, 5);
			for i = -13, 13 do
				for j = -13, 13 do
					test_byte(b, i, j);
				end
			end
		end);

		it("works with characters > 127", function ()
			local b = dbuffer.new();
			b:write(string.char(0, 140));
			local r = { b:byte(1, 2) };
			assert.same({ 0, 140 }, r);
		end);

		it("works on an empty buffer", function ()
			local b = dbuffer.new();
			assert.equal("", b:sub(1,1));
		end);
	end);
end);