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mathieueveillard/jest-mock.ts

Created February 22, 2023 09:34
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Jest mock
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jest-mock.ts
export const createMock = <T>(values: T[] = []) => {
function* generator(): Generator<T, T | undefined, T> {
for (let i = 0; i < values.length; i++) {
yield values[i];
}
return undefined;
}
const generatorInstance = generator();
const mockingFunction = (): T | undefined => {
const a = generatorInstance.next();
return a.value;
};
mockingFunction.returnValueOnce = (value: T) => {
return createMock([...values, value]);
};
return mockingFunction;
};
const mock = createMock().returnValueOnce(100).returnValueOnce(10);
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