How to use the lsat-js.Lsat.fromMacaroon function in lsat-js

it('should return 401 with expiration message if macaroon is expired', async () => {
    const expirationCaveat = getExpirationCaveat(-100)

    macaroon = builder
      .add_first_party_caveat(expirationCaveat.encode())
      .getMacaroon()
      .serialize()

    lsat = Lsat.fromMacaroon(macaroon, invoiceResponse.request)
  
    const response: request.Response = await request
      .agent(app)
      .get(protectedRoute)
      .set('Authorization', lsat.toToken())

    expect(response.status).to.equal(401)
    expect(response).to.have.nested.property('body.error.message')
    // confirm it gives an error message about an expired macaroon
    expect(response.body.error.message).to.match(/expired/g)
  })

it('should return 401 if macaroon is expired', async () => {
      const expirationCaveat = getExpirationCaveat(-100)

      const macaroon = builder
        .add_first_party_caveat(expirationCaveat.encode())
        .getMacaroon()
        .serialize()

      const lsat = Lsat.fromMacaroon(macaroon)

      const response: request.Response = await request
        .agent(app)
        .get('/invoice')
        .set('Authorization', lsat.toToken())

      expect(response.status).to.equal(401)
      expect(response).to.have.nested.property('body.error.message')
      // confirm it gives an error message about an expired macaroon
      expect(response.body.error.message).to.match(/expired/g)
    })

it('should return 401 for invalid macaroon', async () => {
    macaroon = getTestBuilder('another secret')
      .getMacaroon()
      .serialize()
    lsat = Lsat.fromMacaroon(macaroon, invoiceResponse.request)
    
    const response: request.Response = await request
      .agent(app)
      .get(protectedRoute)
      .set('Authorization', lsat.toToken())

    expect(response.status).to.equal(401)
    expect(response).to.have.nested.property('body.error.message')
  })

it('should block access and return 401 for a hodl invoice that is settled', async () => {
    getInvStub.restore()
    getInvStub = getLnStub('getInvoice', {
      ...invoiceResponse,
      is_confirmed: true,
      is_held: false,
    })

    const macaroon = builder.getMacaroon().serialize()
    const lsat = Lsat.fromMacaroon(macaroon, invoiceResponse.request)
    lsat.setPreimage(invoiceResponse.secret)

    await request
      .agent(app)
      .get(protectedRoute)
      .set('Authorization', lsat.toToken())
      .expect(401)
      .expect(res => {
        if (!res.error || !res.body.error.message)
          throw new Error('Expected error message')
        if (!/(expired)|(unauthorized)/gi.test(res.body.error.message))
          throw new Error('Expected error message to mention expired lsat')
      })

    expect(getInvStub.called).to.be.true
  })