local iter = require "util.iterators";

describe("util.iterators", function ()

	describe("join", function ()

		it("should produce a joined iterator", function ()

			local expect = { "a", "b", "c", 1, 2, 3 };

			local output = {};

			for x in iter.join(iter.values({"a", "b", "c"})):append(iter.values({1, 2, 3})) do

				table.insert(output, x);

			end

			assert.same(output, expect);

		end);

		it("should work with only a single iterator", function ()

			local expect = { "a", "b", "c" };

			local output = {};

			for x in iter.join(iter.values({"a", "b", "c"})) do

				table.insert(output, x);

			end

			assert.same(output, expect);

		end);

	end);

	describe("sorted_pairs", function ()

		it("should produce sorted pairs", function ()

			local orig = { b = 1, c = 2, a = "foo", d = false };

			local n, last_key = 0, nil;

			for k, v in iter.sorted_pairs(orig) do

				n = n + 1;

				if last_key then

					assert(k > last_key, "Expected "..k.." > "..last_key)

				end

				assert.equal(orig[k], v);

				last_key = k;

			end

			assert.equal("d", last_key);

			assert.equal(4, n);

		end);

		it("should allow a custom sort function", function ()

			local orig = { b = 1, c = 2, a = "foo", d = false };

			local n, last_key = 0, nil;

			for k, v in iter.sorted_pairs(orig, function (a, b) return a > b end) do

				n = n + 1;

				if last_key then

					assert(k < last_key, "Expected "..k.." > "..last_key)

				end

				assert.equal(orig[k], v);

				last_key = k;

			end

			assert.equal("a", last_key);

			assert.equal(4, n);

		end);

	end);

end);