local template = [[

{greet!?Hi}, {name?world}!

]];

local expect1 = [[

Hello, WORLD!

]];

local expect2 = [[

Hello, world!

]];

local expect3 = [[

Hi, YOU!

]];

local template_array = [[

{foo#{idx}. {item}

}]]

local expect_array = [[

1. HELLO

2. WORLD

]]

local template_func_pipe = [[

{foo|sort#{idx}. {item}

}]]

local expect_func_pipe = [[

1. A

2. B

3. C

4. D

]]

local template_map = [[

{foo%{idx}: {item!}

}]]

local expect_map = [[

FOO: bar

]]

local template_not = [[

{thing~Thing is falsy}{thing&Thing is truthy}

]]

local expect_not_true = [[

Thing is truthy

]]

local expect_not_nil = [[

Thing is falsy

]]

local expect_not_false = [[

Thing is falsy

]]

describe("util.interpolation", function ()

	it("renders", function ()

		local render = require "util.interpolation".new("%b{}", string.upper, { sort = function (t) table.sort(t) return t end });

		assert.equal(expect1, render(template, { greet = "Hello", name = "world" }));

		assert.equal(expect2, render(template, { greet = "Hello" }));

		assert.equal(expect3, render(template, { name = "you" }));

		assert.equal(expect_array, render(template_array, { foo = { "Hello", "World" } }));

		assert.equal(expect_func_pipe, render(template_func_pipe, { foo = { "c", "a", "d", "b", } }));

		-- assert.equal("", render(template_func_pipe, { foo = nil })); -- FIXME

		assert.equal(expect_map, render(template_map, { foo = { foo = "bar" } }));

		assert.equal(expect_not_true, render(template_not, { thing = true }));

		assert.equal(expect_not_nil, render(template_not, { thing = nil }));

		assert.equal(expect_not_false, render(template_not, { thing = false }));

	end);

	it("fixes #1623", function ()

		local render = require "util.interpolation".new("%b{}", string.upper, { x = string.lower });

		assert.equal("", render("{foo?}", {  }))

		assert.equal("", render("{foo|x?}", {  }))

	end);

end);