NodeJS source (edit on github)

If you see a problem with the source submit a pull request on Github.

const stripeCache = require('../../../../stripe-cache.js')

module.exports = {
  patch: async (req) => {
    if (!req.query || !req.query.subscriptionid) {
      throw new Error('invalid-subscriptionid')
    }
    const subscription = await global.api.user.subscriptions.Subscription.get(req)
    if (!subscription) {
      throw new Error('invalid-subscriptionid')
    }
    if (!req.body || !req.body.quantity) {
      throw new Error('invalid-quantity')
    }
    try {
      const quantity = parseInt(req.body.quantity, 10)
      if (quantity < 1 || quantity.toString() !== req.body.quantity) {
        throw new Error('invalid-quantity')
      }
      if (subscription.quantity === quantity) {
        throw new Error('invalid-quantity')
      }
    } catch (error) {
      throw new Error('invalid-quantity')
    }
    // req.query.customerid = subscription.customer.id || subscription.customer
    // const customer = await global.api.user.subscriptions.Customer.get(req)
    const updateInfo = {
      items: [{
        id: subscription.items.data[0].id,
        quantity: req.body.quantity
      }]
    }
    const subscriptionNow = await stripeCache.execute('subscriptions', 'update', req.query.subscriptionid, updateInfo, req.stripeKey)
    if (!subscriptionNow) {
      throw new Error('unknown-error')
    }
    // let upcomingInvoice = await stripeCache.execute('invoices', 'create', {
    //   customer: customer.id,
    //   subscription: subscription.id,
    //   metadata: {
    //     appid: req.appid,
    //     accountid: req.account.accountid
    //   }
    // }, req.stripeKey)
    // const amount = upcomingInvoice.total
    // if (amount > 0) {
    //   upcomingInvoice = await stripeCache.exeecute('invoices', 'pay', upcomingInvoice.id, {
    //     payment_method: req.body.paymentmethodid
    //   }, req.stripeKey)
    //   await stripeCache.update(upcomingInvoice)
    // }
    return subscriptionNow
  }
}

Test source (edit on github)

Tests perform real HTTP requests against a running Dashboard server.

/* eslint-env mocha */
const assert = require('assert')
const TestHelper = require('../../../../../test-helper.js')
const TestStripeAccounts = require('../../../../../test-stripe-accounts.js')

describe('/api/user/subscriptions/set-subscription-quantity', function () {
  this.timeout(60 * 60 * 1000)
  afterEach(TestHelper.deleteOldWebhooks)
  beforeEach(TestHelper.setupWebhook)
  describe('exceptions', () => {
    describe('invalid-subscriptionid', () => {
      it('missing querystring subscriptionid', async () => {
        const user = await TestHelper.createUser()
        const req = TestHelper.createRequest('/api/user/subscriptions/set-subscription-quantity')
        req.account = user.account
        req.session = user.session
        req.body = {
          quantity: '10'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-subscriptionid')
      })

      it('invalid querystring subscriptionid', async () => {
        const user = await TestHelper.createUser()
        const req = TestHelper.createRequest('/api/user/subscriptions/set-subscription-quantity?subscriptionid=invalid')
        req.account = user.account
        req.session = user.session
        req.body = {
          quantity: '10'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-subscriptionid')
      })
    })

    describe('invalid-account', () => {
      it('ineligible accessing account', async () => {
        const administrator = await TestStripeAccounts.createOwnerWithPlan()
        const user = await TestStripeAccounts.createUserWithPaymentMethod()
        await TestHelper.createSubscription(user, administrator.plan.id)
        const user2 = await TestHelper.createUser()
        const req = TestHelper.createRequest(`/api/user/subscriptions/set-subscription-quantity?subscriptionid=${user.subscription.id}`)
        req.account = user2.account
        req.session = user2.session
        req.body = {
          quantity: '1'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-account')
      })
    })

    describe('invalid-quantity', () => {
      it('invalid posted quantity', async () => {
        const administrator = await TestStripeAccounts.createOwnerWithPlan()
        const user = await TestStripeAccounts.createUserWithPaymentMethod()
        await TestHelper.createSubscription(user, administrator.plan.id)
        const req = TestHelper.createRequest(`/api/user/subscriptions/set-subscription-quantity?subscriptionid=${user.subscription.id}`)
        req.account = user.account
        req.session = user.session
        req.body = {
          quantity: 'letters'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-quantity')
      })

      it('invalid posted quantity is unchanged', async () => {
        const administrator = await TestStripeAccounts.createOwnerWithPlan()
        const user = await TestStripeAccounts.createUserWithPaymentMethod()
        await TestHelper.createSubscription(user, administrator.plan.id)
        const req = TestHelper.createRequest(`/api/user/subscriptions/set-subscription-quantity?subscriptionid=${user.subscription.id}`)
        req.account = user.account
        req.session = user.session
        req.body = {
          quantity: '1'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-quantity')
      })

      it('invalid posted quantity is negative', async () => {
        const administrator = await TestStripeAccounts.createOwnerWithPlan()
        const user = await TestStripeAccounts.createUserWithPaymentMethod()
        await TestHelper.createSubscription(user, administrator.plan.id)
        const req = TestHelper.createRequest(`/api/user/subscriptions/set-subscription-quantity?subscriptionid=${user.subscription.id}`)
        req.account = user.account
        req.session = user.session
        req.body = {
          quantity: '-1'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-quantity')
      })

      it('invalid posted quantity is zero', async () => {
        const administrator = await TestStripeAccounts.createOwnerWithPlan()
        const user = await TestStripeAccounts.createUserWithPaymentMethod()
        await TestHelper.createSubscription(user, administrator.plan.id)
        const req = TestHelper.createRequest(`/api/user/subscriptions/set-subscription-quantity?subscriptionid=${user.subscription.id}`)
        req.account = user.account
        req.session = user.session
        req.body = {
          quantity: '0'
        }
        let errorMessage
        try {
          await req.patch(req)
        } catch (error) {
          errorMessage = error.message
        }
        assert.strictEqual(errorMessage, 'invalid-quantity')
      })
    })
  })

  describe('returns', () => {
    it('object', async () => {
      const administrator = await TestStripeAccounts.createOwnerWithPlan()
      const user = await TestStripeAccounts.createUserWithPaymentMethod()
      await TestHelper.createSubscription(user, administrator.plan.id)
      const req = TestHelper.createRequest(`/api/user/subscriptions/set-subscription-quantity?subscriptionid=${user.subscription.id}`)
      req.account = user.account
      req.session = user.session
      req.body = {
        quantity: '2'
      }
      req.filename = __filename
      req.saveResponse = true
      const subscriptionNow = await req.patch()
      assert.strictEqual(subscriptionNow.quantity, 2)
    })
  })
})