Stubbed Dependency

A stub replaces an outside dependency with a predictable in-memory value.

stub.ts

type PriceSource = {
    getPrice(sku: string): number;
};

function totalFor(source: PriceSource, sku: string, quantity: number): number {
    return source.getPrice(sku) * quantity;
}

const price: number = ;
const stubSource: PriceSource = {
    getPrice: () => price,
};

const total: number = totalFor(stubSource, "book", 3);

console.log(`total=${total}`);

type PriceSource = {
    getPrice(sku: string): number;
};

function totalFor(source: PriceSource, sku: string, quantity: number): number {
    return source.getPrice(sku) * quantity;
}

const price: number = ;
const stubSource: PriceSource = {
    getPrice: () => price,
};

const total: number = totalFor(stubSource, "book", 3);

console.log(`total=${total}`);

stub A stub implements the same small interface as a dependency, but it returns fixed data for the test.