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Diffstat (limited to 'packages/web-util/src/tests/hook.ts')
-rw-r--r-- | packages/web-util/src/tests/hook.ts | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/packages/web-util/src/tests/hook.ts b/packages/web-util/src/tests/hook.ts new file mode 100644 index 000000000..f5bebbd6d --- /dev/null +++ b/packages/web-util/src/tests/hook.ts @@ -0,0 +1,310 @@ +/* + This file is part of GNU Taler + (C) 2022 Taler Systems S.A. + + GNU Taler is free software; you can redistribute it and/or modify it under the + terms of the GNU General Public License as published by the Free Software + Foundation; either version 3, or (at your option) any later version. + + GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR + A PARTICULAR PURPOSE. See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along with + GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/> + */ + +import { + ComponentChildren, + Fragment, + FunctionalComponent, + h as create, + options, + render as renderIntoDom, + VNode +} from "preact"; + +// This library is expected to be included in testing environment only +// When doing tests we want the requestAnimationFrame to be as fast as possible. +// without this option the RAF will timeout after 100ms making the tests slower +options.requestAnimationFrame = (fn: () => void) => { + return fn(); +}; + +export function createExample<Props>( + Component: FunctionalComponent<Props>, + props: Partial<Props> | (() => Partial<Props>), +): ComponentChildren { + const evaluatedProps = typeof props === "function" ? props() : props; + const Render = (args: any): VNode => create(Component, args); + + return { + component: Render, + props: evaluatedProps, + }; +} + +// export function createExampleWithCustomContext<Props, ContextProps>( +// Component: FunctionalComponent<Props>, +// props: Partial<Props> | (() => Partial<Props>), +// ContextProvider: FunctionalComponent<ContextProps>, +// contextProps: Partial<ContextProps>, +// ): ComponentChildren { +// /** +// * FIXME: +// * This may not be useful since the example can be created with context +// * already +// */ +// const evaluatedProps = typeof props === "function" ? props() : props; +// const Render = (args: any): VNode => create(Component, args); +// const WithContext = (args: any): VNode => +// create(ContextProvider, { +// ...contextProps, +// children: [Render(args)], +// } as any); + +// return { +// component: WithContext, +// props: evaluatedProps, +// }; +// } + +const isNode = typeof window === "undefined"; + +/** + * To be used on automated unit test. + * So test will run under node or browser + * @param Component + * @param args + */ +export function renderNodeOrBrowser( + Component: any, + args: any, + Context: any, +): void { + const vdom = !Context + ? create(Component, args) + : create(Context, { children: [create(Component, args)] }); + + const customElement = {} as Element; + const parentElement = isNode ? customElement : document.createElement("div"); + if (!isNode) { + document.body.appendChild(parentElement); + } + + // renderIntoDom works also in nodejs + // if the VirtualDOM is composed only by functional components + // then no called is going to be made to the DOM api. + // vdom should not have any 'div' or other html component + renderIntoDom(vdom, parentElement); + + if (!isNode) { + document.body.removeChild(parentElement); + } +} +type RecursiveState<S> = S | (() => RecursiveState<S>); + +interface Mounted<T> { + // unmount: () => void; + pullLastResultOrThrow: () => Exclude<T, VoidFunction>; + assertNoPendingUpdate: () => Promise<boolean>; + // waitNextUpdate: (s?: string) => Promise<void>; + waitForStateUpdate: () => Promise<boolean>; +} + +/** + * Manual API mount the hook and return testing API + * Consider using hookBehaveLikeThis() function + * + * @param hookToBeTested + * @param Context + * + * @returns testing API + */ +export function mountHook<T extends object>( + hookToBeTested: () => RecursiveState<T>, + Context?: ({ children }: { children: any }) => VNode | null, +): Mounted<T> { + let lastResult: Exclude<T, VoidFunction> | Error | null = null; + + const listener: Array<() => void> = []; + + // component that's going to hold the hook + function Component(): VNode { + try { + let componentOrResult = hookToBeTested(); + while (typeof componentOrResult === "function") { + componentOrResult = componentOrResult(); + } + //typecheck fails here + const l: Exclude<T, () => void> = componentOrResult as any; + lastResult = l; + } catch (e) { + if (e instanceof Error) { + lastResult = e; + } else { + lastResult = new Error(`mounting the hook throw an exception: ${e}`); + } + } + + // notify to everyone waiting for an update and clean the queue + listener.splice(0, listener.length).forEach((cb) => cb()); + return create(Fragment, {}); + } + + renderNodeOrBrowser(Component, {}, Context); + + function pullLastResult(): Exclude<T | Error | null, VoidFunction> { + const copy: Exclude<T | Error | null, VoidFunction> = lastResult; + lastResult = null; + return copy; + } + + function pullLastResultOrThrow(): Exclude<T, VoidFunction> { + const r = pullLastResult(); + if (r instanceof Error) throw r; + //sanity check + if (!r) throw Error("there was no last result"); + return r; + } + + async function assertNoPendingUpdate(): Promise<boolean> { + await new Promise((res, rej) => { + const tid = setTimeout(() => { + res(true); + }, 10); + + listener.push(() => { + clearTimeout(tid); + res(false); + // Error(`Expecting no pending result but the hook got updated. + // If the update was not intended you need to check the hook dependencies + // (or dependencies of the internal state) but otherwise make + // sure to consume the result before ending the test.`), + // ); + }); + }); + + const r = pullLastResult(); + if (r) { + return Promise.resolve(false); + } + return Promise.resolve(true); + // throw Error(`There are still pending results. + // This may happen because the hook did a new update but the test didn't consume the result using pullLastResult`); + } + async function waitForStateUpdate(): Promise<boolean> { + return await new Promise((res, rej) => { + const tid = setTimeout(() => { + res(false); + }, 10); + + listener.push(() => { + clearTimeout(tid); + res(true); + }); + }); + } + + return { + // unmount, + pullLastResultOrThrow, + waitForStateUpdate, + assertNoPendingUpdate, + }; +} + +export const nullFunction = (): void => { + null; +}; +export const nullAsyncFunction = (): Promise<void> => { + return Promise.resolve(); +}; + +type HookTestResult = HookTestResultOk | HookTestResultError; + +interface HookTestResultOk { + result: "ok"; +} +interface HookTestResultError { + result: "fail"; + error: string; + index: number; +} + +/** + * Main testing driver. + * It will assert that there are no more and no less hook updates than expected. + * + * @param hookFunction hook function to be tested + * @param props initial props for the hook + * @param checks step by step state validation + * @param Context additional testing context for overrides + * + * @returns testing result, should also be checked to be "ok" + */ +export async function hookBehaveLikeThis<T extends object, PropsType>( + hookFunction: (p: PropsType) => RecursiveState<T>, + props: PropsType, + checks: Array<(state: T) => void>, + Context?: ({ children }: { children: any }) => VNode | null, +): Promise<HookTestResult> { + const { pullLastResultOrThrow, waitForStateUpdate, assertNoPendingUpdate } = + mountHook<T>(() => hookFunction(props), Context); + + const [firstCheck, ...resultOfTheChecks] = checks; + { + const state = pullLastResultOrThrow(); + const checkError = firstCheck(state); + if (checkError !== undefined) { + return { + result: "fail", + index: 0, + error: `Check return not undefined error: ${checkError}`, + }; + } + } + + let index = 1; + for (const check of resultOfTheChecks) { + const hasNext = await waitForStateUpdate(); + if (!hasNext) { + return { + result: "fail", + error: "Component didn't update and the test expected one more state", + index, + }; + } + const state = pullLastResultOrThrow(); + const checkError = check(state); + if (checkError !== undefined) { + return { + result: "fail", + index, + error: `Check return not undefined error: ${checkError}`, + }; + } + index++; + } + + const hasNext = await waitForStateUpdate(); + if (hasNext) { + return { + result: "fail", + index, + error: "Component updated and test didn't expect more states", + }; + } + const noMoreUpdates = await assertNoPendingUpdate(); + if (noMoreUpdates === false) { + return { + result: "fail", + index, + error: "Component was updated but the test does not cover the update", + }; + } + + return { + result: "ok", + }; +} |