NARKOZ · NARKOZ · Jun 18, 2025 · Mar 21, 2025
diff --git a/lib/gitlab/configuration.rb b/lib/gitlab/configuration.rb
@@ -5,7 +5,7 @@ module Gitlab
   # Defines constants and methods related to configuration.
   module Configuration
     # An array of valid keys in the options hash when configuring a Gitlab::API.
-    VALID_OPTIONS_KEYS = %i[endpoint private_token user_agent sudo httparty pat_prefix].freeze
+    VALID_OPTIONS_KEYS = %i[endpoint private_token user_agent sudo httparty pat_prefix body_as_json].freeze
 
     # The user agent that will be sent to the API endpoint if none is set.
     DEFAULT_USER_AGENT = "Gitlab Ruby Gem #{Gitlab::VERSION}"
@@ -41,6 +41,7 @@ def reset
       self.httparty       = get_httparty_config(ENV['GITLAB_API_HTTPARTY_OPTIONS'])
       self.sudo           = nil
       self.user_agent     = DEFAULT_USER_AGENT
+      self.body_as_json   = false
     end
 
     private

diff --git a/lib/gitlab/request.rb b/lib/gitlab/request.rb
@@ -12,7 +12,7 @@ class Request
     headers 'Accept' => 'application/json', 'Content-Type' => 'application/x-www-form-urlencoded'
     parser(proc { |body, _| parse(body) })
 
-    attr_accessor :private_token, :endpoint, :pat_prefix
+    attr_accessor :private_token, :endpoint, :pat_prefix, :body_as_json
 
     # Converts the response body to an ObjectifiedHash.
     def self.parse(body)
@@ -49,6 +49,8 @@ def self.decode(response)
           params[:headers].merge!(authorization_header)
         end
 
+        jsonify_body_content(params) if body_as_json
+
         retries_left = params[:ratelimit_retries] || 3
         begin
           response = self.class.send(method, endpoint + path, params)
@@ -114,5 +116,24 @@ def authorization_header
     def httparty_config(options)
       options.merge!(httparty) if httparty
     end
+
+    # Handle 'body_as_json' configuration option
+    # Modifies passed params in place.
+    def jsonify_body_content(params)
+      # Only modify the content type if there is a body to process AND multipath
+      # was not explicitly requested. There are no uses of multipart in this code
+      # today, but file upload methods require it and someone might be manually
+      # crafting a post call with it:
+      return unless params[:body] && params[:multipart] != true
+
+      # If the caller explicitly requested a Content-Type during the call, assume
+      # they know best and have formatted the body as required:
+      return if params[:headers]&.key?('Content-Type')
+
+      # If we make it here, then we assume it is safe to JSON encode the body:
+      params[:headers] ||= {}
+      params[:headers]['Content-Type'] = 'application/json'
+      params[:body] = params[:body].to_json
+    end
   end
 end
diff --git a/spec/gitlab/request_spec.rb b/spec/gitlab/request_spec.rb
@@ -15,6 +15,7 @@
   it { is_expected.to respond_to :post }
   it { is_expected.to respond_to :put }
   it { is_expected.to respond_to :delete }
+  it { is_expected.to respond_to :patch }
 
   describe '.default_options' do
     it 'has default values' do
@@ -288,4 +289,33 @@
       ).to have_been_made
     end
   end
+
+  describe 'JSON request bodies' do
+    subject(:request) { described_class.new }
+
+    let(:endpoint) { 'https://example.com/api/v4' }
+    let(:path) { '/testpath' }
+    let(:request_path) { "#{endpoint}#{path}" }
+
+    before do
+      request.private_token = 'token'
+      request.endpoint = endpoint
+      request.body_as_json = true
+      allow(request).to receive(:httparty) # rubocop:disable RSpec/SubjectStub
+
+      stub_request(:post, request_path).with(headers: { 'Content-Type' => 'application/json' })
+    end
+
+    it 'makes a request with application/json encoding when no Content-Type is specified' do
+      request.post(path, body: { param: 'val' })
+
+      expect(a_request(:post, request_path).with(body: { param: 'val' }.to_json)).to have_been_made
+    end
+
+    it 'passes the unmodified request when a Content-Type is specified' do
+      request.post(path, body: { param: 'val' }.to_json, headers: { 'Content-Type' => 'application/json' })
+
+      expect(a_request(:post, request_path).with(body: { param: 'val' }.to_json)).to have_been_made
+    end
+  end
 end