--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spec/util_interpolation_spec.lua	Sat Mar 10 19:58:41 2018 +0100
@@ -0,0 +1,17 @@
+local template = [[
+{greet!}, {name?world}!
+]];
+local expect1 = [[
+Hello, WORLD!
+]];
+local expect2 = [[
+Hello, world!
+]];
+
+describe("util.interpolation", function ()
+	it("renders", function ()
+		local render = require "util.interpolation".new("%b{}", string.upper);
+		assert.equal(expect1, render(template, { greet = "Hello", name = "world" }));
+		assert.equal(expect2, render(template, { greet = "Hello" }));
+	end);
+end);