ladybird/Userland/Libraries/LibJS/Tests/loops/for-await-of.js

95 lines
2.8 KiB
JavaScript

describe("basic behavior", () => {
test("empty array", () => {
var enteredFunction = false;
var rejected = false;
async function f() {
enteredFunction = true;
for await (const v of []) {
expect().fail("Should not enter loop");
}
}
f().then(
() => {
expect(enteredFunction).toBeTrue();
},
() => {
rejected = true;
}
);
runQueuedPromiseJobs();
expect(enteredFunction).toBeTrue();
expect(rejected).toBeFalse();
});
test("sync iterator", () => {
var loopIterations = 0;
var rejected = false;
async function f() {
for await (const v of [1]) {
expect(v).toBe(1);
loopIterations++;
}
}
f().then(
() => {
expect(loopIterations).toBe(1);
},
() => {
rejected = true;
}
);
runQueuedPromiseJobs();
expect(loopIterations).toBe(1);
expect(rejected).toBeFalse();
});
test("can break a for-await-of loop", () => {
var loopIterations = 0;
var rejected = false;
async function f() {
for await (const v of [1, 2, 3]) {
expect(v).toBe(1);
loopIterations++;
break;
}
}
f().then(
() => {
expect(loopIterations).toBe(1);
},
() => {
rejected = true;
}
);
runQueuedPromiseJobs();
expect(loopIterations).toBe(1);
expect(rejected).toBeFalse();
});
});
describe("only allowed in async functions", () => {
test("async functions", () => {
expect("async function foo() { for await (const v of []) return v; }").toEval();
expect("(async function () { for await (const v of []) return v; })").toEval();
expect("async () => { for await (const v of []) return v; }").toEval();
});
test("regular functions", () => {
expect("function foo() { for await (const v of []) return v; }").not.toEval();
expect("(function () { for await (const v of []) return v; })").not.toEval();
expect("() => { for await (const v of []) return v; }").not.toEval();
});
test("generator functions", () => {
expect("function* foo() { for await (const v of []) return v; }").not.toEval();
expect("(function* () { for await (const v of []) return v; })").not.toEval();
});
test("async generator functions", () => {
expect("async function* foo() { for await (const v of []) yield v; }").toEval();
expect("(async function* () { for await (const v of []) yield v; })").toEval();
});
});