fix: Use JSON Content-Type in mutating requests

The Backend API supports both form-urlencoded and application/json
content types in requests. However, we're slowly fading out support for
form-urlencoded and transitioning to application/json.

Most important, the Ruby SDK generated payloads that the Backend API
couldn't properly unmarshal, particularly in the case of payloads like
the following:

    { backup_codes: ["abcdef", "zxcqwe"] }

in such cases, the resulting payload would be:

   backup_codes[]: "abcdef; zxcqwe"

which the Backend API didn't know how to properly parse.

Fixes AUTH-129

.gitignore

@@ -8,6 +8,8 @@
 /tmp/
 
 .byebug_history
+.ruby-version
 *.gem
 
 .idea
+

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    clerk-sdk-ruby (2.8.0)
+    clerk-sdk-ruby (2.9.0.beta2)
       concurrent-ruby (~> 1.1)
       faraday (~> 1.4.1)
       jwt (~> 2.5)
@@ -24,8 +24,8 @@ GEM
     faraday-excon (1.1.0)
     faraday-net_http (1.0.1)
     faraday-net_http_persistent (1.2.0)
-    jwt (2.5.0)
-    minitest (5.16.3)
+    jwt (2.6.0)
+    minitest (5.17.0)
     multipart-post (2.2.3)
     rake (13.0.6)
     ruby2_keywords (0.0.5)

lib/clerk/resources/singular_resource.rb

@@ -7,7 +7,7 @@ def initialize(client, resource_path)
       end
 
       def update(changes = {})
-        @client.request(:patch, @resource_path, body:changes)
+        @client.request(:patch, @resource_path, body: changes)
       end
     end
   end

lib/clerk/sdk.rb

@@ -74,12 +74,14 @@ def request(method, path, query: [], body: nil, timeout: nil)
                    end
                  when :post
                    @conn.post(path, body) do |req|
-                     req.body = body
+                     req.body = body.to_json
+                     req.headers[:content_type] = "application/json"
                      req.options.timeout = timeout if timeout
                    end
                  when :patch
                    @conn.patch(path, body) do |req|
-                     req.body = body
+                     req.body = body.to_json
+                     req.headers[:content_type] = "application/json"
                      req.options.timeout = timeout if timeout
                    end
                  when :delete

test/sdk_test.rb

@@ -11,6 +11,30 @@ def test_sdk_init_without_config
     assert sdk
   end
 
+  def test_application_json_encoding
+    unparsed_payload  = { a: "b", c: ["d"], d: { e: 3 } }
+    json_payload      = '{"a":"b","c":["d"],"d":{"e":3}}'
+
+    conn = Faraday.new do |faraday|
+      faraday.adapter :test do |stub|
+        stub.patch("/users/user_1", json_payload, { "Content-Type" => "application/json" } ) do |env|
+          parsed = JSON.parse(env.request_body)
+          parsed["a"] = "b"
+          parsed["c"] = ["d"]
+          parsed["d"] = { "e" => 3 }
+
+          json_ok("user_1_updated")
+        end
+      end
+    end
+
+    sdk = ::Clerk::SDK.new(connection: conn)
+    user = sdk.users.update("user_1", unparsed_payload)
+
+    assert_equal "Mary", user["first_name"]
+    assert_equal "user_1", user["id"]
+  end
+
   def test_no_api_key_raises_on_api_call
     sdk = ::Clerk::SDK.new
     assert_raises ArgumentError do