File

spec/util_ringbuffer_spec.lua @ 12446:e54b8a5e35ad 0.12

util.random: Test whether util.crand works before using it (fix #1734) util.crand can be configured at compile time to use the Linux getrandom() system call, available from Linux 3.17, but it is still possible to load it with an older kernel lacking that system call, where attempting to use it throws an ENOSYS error. By testing for this on load we can fall back to /dev/urandom in this case.
author Kim Alvefur <zash@zash.se>
date Sat, 02 Apr 2022 16:33:27 +0200
parent 10960:f84e0e2faae2
line wrap: on
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local rb = require "util.ringbuffer";
describe("util.ringbuffer", function ()
	describe("#new", function ()
		it("has a constructor", function ()
			assert.Function(rb.new);
		end);
		it("can be created", function ()
			assert.truthy(rb.new());
		end);
		it("won't create an empty buffer", function ()
			assert.has_error(function ()
				rb.new(0);
			end);
		end);
		it("won't create a negatively sized buffer", function ()
			assert.has_error(function ()
				rb.new(-1);
			end);
		end);
	end);
	describe(":write", function ()
		local b = rb.new();
		it("works", function ()
			assert.truthy(b:write("hi"));
		end);
	end);

	describe(":discard", function ()
		local b = rb.new();
		it("works", function ()
			assert.truthy(b:write("hello world"));
			assert.truthy(b:discard(6));
			assert.equal(5, #b);
			assert.equal("world", b:read(5));
		end);
	end);

	describe(":sub", function ()
		-- Helper function to compare buffer:sub() with string:sub()
		local function test_sub(b, x, y)
			local s = b:read(#b, true);
			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 = rb.new();
			assert.truthy(b:write("hello world"));
			assert.equals("hello", b:sub(1, 5));
		end);

		it("supports optional end parameter", function ()
			local b = rb.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 = rb.new(6);
			assert.truthy(b:write("foobar"));
			b:read(3);
			b:write("foo");
			for i = -13, 13 do
				for j = -13, 13 do
					test_sub(b, i, j);
				end
			end
		end);
	end);

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

		it("is equivalent to string:byte", function ()
			local b = rb.new(6);
			assert.truthy(b:write("foobar"));
			b:read(3);
			b:write("foo");
			test_byte(b, 1);
			test_byte(b, 3);
			test_byte(b, -1);
			test_byte(b, -3);
			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 = rb.new();
			b:write(string.char(0, 140));
			local r = { b:byte(1, 2) };
			assert.same({ 0, 140 }, r);
		end);
	end);
end);