cesnimda
37 lines
1.2 KiB
TypeScript
37 lines
1.2 KiB
TypeScript
import React from "react";
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import "@testing-library/jest-dom";
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import { act, render, screen } from "@testing-library/react";
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import { useViewResource } from "./hooks/useViewResource";
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function deferred<T>() {
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let resolve!: (value: T) => void;
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const promise = new Promise<T>((next) => { resolve = next; });
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return { promise, resolve };
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}
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it("ignores an older request that completes after a newer dependency load", async () => {
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const first = deferred<string>();
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const second = deferred<string>();
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const load = jest.fn((key: string) => key === "first" ? first.promise : second.promise);
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function Probe({ query }: { query: string }) {
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const resource = useViewResource(() => load(query), {
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initialData: "empty",
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errorMessage: "Unable to load.",
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deps: [query],
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});
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return <div>{resource.data}</div>;
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}
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const view = render(<Probe query="first" />);
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view.rerender(<Probe query="second" />);
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await act(async () => { second.resolve("new result"); });
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expect(screen.getByText("new result")).toBeInTheDocument();
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await act(async () => { first.resolve("stale result"); });
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expect(screen.getByText("new result")).toBeInTheDocument();
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expect(screen.queryByText("stale result")).not.toBeInTheDocument();
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});
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