ladybird/Userland/Libraries/LibJS/Tests/syntax/optional-chaining.js

40 lines
1.1 KiB
JavaScript

test("parse optional-chaining", () => {
expect(`a?.b`).toEval();
expect(`a?.4:.5`).toEval();
expect(`a?.[b]`).toEval();
expect(`a?.b[b]`).toEval();
expect(`a?.b(c)`).toEval();
expect(`a?.b?.(c, d)`).toEval();
expect(`a?.b?.()`).toEval();
expect("a?.b``").not.toEval();
expect("a?.b?.``").not.toEval();
expect("new Foo?.bar").not.toEval();
expect("new (Foo?.bar)").toEval();
// FIXME: This should pass.
// expect("(new Foo)?.bar").toEval();
});
test("evaluate optional-chaining", () => {
for (let nullishObject of [null, undefined]) {
expect((() => nullishObject?.b)()).toBeUndefined();
}
expect(
(() => {
let a = {};
return a?.foo?.bar?.baz;
})()
).toBeUndefined();
expect(
(() => {
let a = { foo: { bar: () => 42 } };
return `${a?.foo?.bar?.()}-${a?.foo?.baz?.()}`;
})()
).toBe("42-undefined");
expect(() => {
let a = { foo: { bar: () => 42 } };
return a.foo?.baz.nonExistentProperty;
}).toThrow();
});