add support for voiding invoices

.travis.yml

@@ -10,7 +10,7 @@ otp_release:
 sudo: false
 env:
   global:
-    - STRIPE_MOCK_VERSION=0.38.0
+    - STRIPE_MOCK_VERSION=0.40.0
     - MIX_ENV=test STRIPE_SECRET_KEY=non_empty_secret_key_string
 cache:
   directories:

lib/stripe/subscriptions/invoice.ex

@@ -7,6 +7,7 @@ defmodule Stripe.Invoice do
   - Create an invoice
   - Retrieve an invoice
   - Update an invoice
+  - Void an invoice
 
   Does not take options yet.
 
@@ -237,4 +238,15 @@ defmodule Stripe.Invoice do
     |> cast_to_id([:source])
     |> make_request()
   end
+
+  @doc """
+  Void an invoice
+  """
+  @spec void(Stripe.id() | t, Stripe.options()) :: {:ok, t} | {:error, Stripe.Error.t()}
+  def void(id, opts \\ []) do
+    new_request(opts)
+    |> put_endpoint(@plural_endpoint <> "/#{get_id!(id)}/void")
+    |> put_method(:post)
+    |> make_request()
+  end
 end

test/stripe/payment_methods/source_test.exs

@@ -33,8 +33,7 @@ defmodule Stripe.SourceTest do
 
   describe "detach/2" do
     test "detaches a source from a customer" do
-      assert {:ok, %{deleted: true, id: "src_123"}} =
-               Stripe.Source.detach("src_123", %{customer: "cus_123"})
+      assert {:ok, %{id: "src_123"}} = Stripe.Source.detach("src_123", %{customer: "cus_123"})
 
       assert_stripe_requested(:delete, "/v1/customers/cus_123/sources/src_123")
     end

test/stripe/subscriptions/invoice_test.exs

@@ -87,4 +87,12 @@ defmodule Stripe.InvoiceTest do
       assert %Stripe.Invoice{} = hd(invoices)
     end
   end
+
+  describe "void/2" do
+    test "voids an invoice" do
+      {:ok, invoice} = Stripe.Invoice.retrieve("in_123")
+      assert {:ok, %Stripe.Invoice{} = _voided_invoice} = Stripe.Invoice.void(invoice)
+      assert_stripe_requested(:post, "/v1/invoices/#{invoice.id}/void")
+    end
+  end
 end