importing instance for jest mock

I wanted to do something like

jest.mock<typeof import("common/client/constants/local-player")>(
    import("common/client/constants/local-player").await(),
    () => {
        const mockPlayer = {
            Name: "TestPlayer",
            UserId: 123456,
        } as Player;

        return {
            LocalPlayer: mockPlayer,
        };
    },
);

jest.mock<typeof import("common/client/constants/local-player")>(
    import("common/client/constants/local-player").await(),
    () => {
        const mockPlayer = {
            Name: "TestPlayer",
            UserId: 123456,
        } as Player;

        return {
            LocalPlayer: mockPlayer,
        };
    },
);

to mock my modules to return the correct value. The import syntax returns a promise and a unknown type which isn't ideal. Is there a better way other than directly indexing from the data model to mock the module script?

Solution:

@duck https://gist.github.com/lisachandra/d37791fbe77f66690f0c6ec51b78b3a0

Gist

jest roblox-ts testing utils

jest roblox-ts testing utils. GitHub Gist: instantly share code, notes, and snippets.

Jump to solution

17 Replies

duckOP•3mo ago

bump

lisachandra•3mo ago

i don't think there's any better way to do it ig you could mock the services itself

const servicesModule = getModuleByTree(...$getModuleTree("@rbxts/services"));
        jest.mock<typeof import("@rbxts/services")>(servicesModule, () => {
            const originalServices: typeof import("@rbxts/services") =
                jest.requireActual(servicesModule);

            mockServices ??= mockOnRuntime(jest, createMockInstance(originalServices));
            return mockServices;
        });

const servicesModule = getModuleByTree(...$getModuleTree("@rbxts/services"));
        jest.mock<typeof import("@rbxts/services")>(servicesModule, () => {
            const originalServices: typeof import("@rbxts/services") =
                jest.requireActual(servicesModule);

            mockServices ??= mockOnRuntime(jest, createMockInstance(originalServices));
            return mockServices;
        });

duckOP•3mo ago

I tried using $getModuleTree

lisachandra•3mo ago

yea thats how u do it

duckOP•3mo ago

does that work for file specific modules like in my case, LocalPlayer

lisachandra•3mo ago

yea those functions are from my testing utils

duckOP•3mo ago

can you send me it 🙏

lisachandra•3mo ago

sure lol wait

duckOP•3mo ago

thx

Solution

lisachandra•3mo ago

@duck https://gist.github.com/lisachandra/d37791fbe77f66690f0c6ec51b78b3a0

Gist

jest roblox-ts testing utils

jest roblox-ts testing utils. GitHub Gist: instantly share code, notes, and snippets.

lisachandra•3mo ago

haven't tested the usage stuff yet but something like that should work oh yeah i also mock the ts runtime just incase of any weird errors although im not really sure if it does anything or not

const tsRuntimeModule = getModuleByTree(...$getModuleTree("include/RuntimeLib"));
const tsRuntime = require(tsRuntimeModule) as typeof import("include/RuntimeLib");
jest.mock<typeof import("include/RuntimeLib")>(tsRuntimeModule, () => tsRuntime);

const tsRuntimeModule = getModuleByTree(...$getModuleTree("include/RuntimeLib"));
const tsRuntime = require(tsRuntimeModule) as typeof import("include/RuntimeLib");
jest.mock<typeof import("include/RuntimeLib")>(tsRuntimeModule, () => tsRuntime);

duckOP•3mo ago

hmmm

lisachandra•3mo ago

could be useful if u wanna mock the internals like generators n stuff

duckOP•3mo ago

thanks jest is so good

lisachandra•3mo ago

it really is

duckOP•3mo ago

mocking alr i'll mark this as solved

lisachandra•3mo ago

actually you might need the runtime files aswell lmk when you need it cus i gtg rn

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importing instance for jest mock

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