exports["test first"] = assert => {
let test = (xs, empty) => {
assert.equal(first(xs), 1, "returns first");
assert.equal(first(empty), null, "returns null empty");
};
test("1234", "");
test([1, 2, 3], []);
test([1, 2, 3], null);
test([1, 2, 3], undefined);
test(seq(function*() { yield 1; yield 2; yield 3; }),
seq(function*() { }));
assert.equal(first(broken), 1, "did not reached error");
};
let test = (xs, empty) => {
assert.equal(first(xs), 1, "returns first");
assert.equal(first(empty), null, "returns null empty");
};