44 lines
1.0 KiB
JavaScript
44 lines
1.0 KiB
JavaScript
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/* eslint-env jest */
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const { deduped } = require('./deduped')
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describe('deduped()', () => {
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it('calls the resource function only once', async () => {
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const value = {}
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const getResource = jest.fn(async () => ({
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value,
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dispose: Function.prototype,
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}))
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const dedupedGetResource = deduped(getResource)
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const { value: v1 } = await dedupedGetResource()
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const { value: v2 } = await dedupedGetResource()
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expect(getResource).toHaveBeenCalledTimes(1)
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expect(v1).toBe(value)
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expect(v2).toBe(value)
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})
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it('only disposes the source disposable when its all copies dispose', async () => {
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const dispose = jest.fn()
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const getResource = async () => ({
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value: '',
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dispose,
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})
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const dedupedGetResource = deduped(getResource)
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const { dispose: d1 } = await dedupedGetResource()
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const { dispose: d2 } = await dedupedGetResource()
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d1()
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expect(dispose).not.toHaveBeenCalled()
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d2()
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expect(dispose).toHaveBeenCalledTimes(1)
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})
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})
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