util.bitcompat: Add some simple tests

spec/util_bitcompat_spec.lua

@@ -0,0 +1,27 @@
+describe("util.bitcompat", function ()
+	-- bitcompat will pass through to an appropriate implementation. Our
+	-- goal here is to check that whatever implementation is in use passes
+	-- these basic sanity checks.
+
+	local bit = require "util.bitcompat";
+
+	it("bor works", function ()
+		assert.equal(0xF0FF, bit.bor(0xF000, 0x00F0, 0x000F));
+	end);
+
+	it("band works", function ()
+		assert.equal(0x0F, bit.band(0xFF, 0x1F, 0x0F));
+	end);
+
+	it("bxor works", function ()
+		assert.equal(0x13, bit.bxor(0x10, 0x0F, 0x0C));
+	end);
+
+	it("rshift works", function ()
+		assert.equal(0x0F, bit.rshift(0xFF, 4));
+	end);
+
+	it("lshift works", function ()
+		assert.equal(0xFF00, bit.lshift(0xFF, 8));
+	end);
+end);