Fix json >= 3.0 compatibility

.github/workflows/test.yml

@@ -17,14 +17,13 @@ jobs:
         gemfile:
           - Gemfile
         include:
-          # See https://github.com/dblock/strava-ruby-client/issues/113: json
-          # 2.x is the version this gem currently supports. json_3 is
-          # commented out until Faraday's :json middleware supports json >=
-          # 3.0, since it currently fails (Faraday::ParsingError).
+          # See https://github.com/dblock/strava-ruby-client/issues/113: this
+          # gem no longer relies on Faraday's built-in :json response
+          # middleware, so it works with both json < 3.0 and json >= 3.0.
           - ruby-version: "3.4"
             gemfile: gemfiles/json_2.gemfile
-          # - ruby-version: "3.4"
-          #   gemfile: gemfiles/json_3.gemfile
+          - ruby-version: "3.4"
+            gemfile: gemfiles/json_3.gemfile
     env:
       BUNDLE_GEMFILE: ${{ matrix.gemfile }}
     steps:

CHANGELOG.md

@@ -1,6 +1,7 @@
 ### 3.1.1 (Next)
 
 * [#113](https://github.com/dblock/strava-ruby-client/issues/113): Adds Appraisals (`json-2`, `json-3`) - [@dblock](https://github.com/dblock).
+* [#113](https://github.com/dblock/strava-ruby-client/issues/113): Fixed `ArgumentError` when parsing JSON responses with `json` gem >= 3.0 by replacing Faraday's built-in `:json` response middleware with a compatible one - [@dblock](https://github.com/dblock).
 * Your contribution here.
 
 ### 3.1.0 (2026/08/29)

Gemfile

@@ -4,12 +4,6 @@ source 'http://rubygems.org'
 
 gemspec
 
-# Faraday's :json response middleware is incompatible with json >= 3.0 (see
-# https://github.com/dblock/strava-ruby-client/issues/113), so pin json here
-# rather than relying on rubocop's own transitive constraint. The `json-3`
-# appraisal (see Appraisals) is used to track when this can be removed.
-gem 'json', '~> 2.3'
-
 group :development, :test do
   gem 'appraisal'
   gem 'csv'

lib/strava-ruby-client.rb

@@ -90,6 +90,7 @@
 require_relative 'strava/models/zones'
 
 require_relative 'strava/web/raise_response_error'
+require_relative 'strava/web/json_response'
 require_relative 'strava/web/connection'
 require_relative 'strava/web/api_response'
 require_relative 'strava/web/request'

lib/strava/web/connection.rb

@@ -67,7 +67,7 @@ def connection
             connection.request :multipart
             connection.request :url_encoded
             connection.use Strava::Web::RaiseResponseError
-            connection.response :json
+            connection.use Strava::Web::JsonResponse
             connection.response :logger, logger if logger
             connection.adapter ::Faraday.default_adapter
           end

lib/strava/web/json_response.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module Strava
+  module Web
+    #
+    # Faraday response middleware that parses JSON response bodies.
+    #
+    # This is a drop-in replacement for Faraday's built-in +:json+ response
+    # middleware (+Faraday::Response::Json+), which calls
+    # +JSON.parse(body, options)+ with a positional options hash. The
+    # +json+ gem 3.0 changed +JSON.parse+ to accept options as keyword
+    # arguments only, so that call raises
+    # +ArgumentError: wrong number of arguments (given 2, expected 1)+,
+    # surfaced by Faraday as +Faraday::ParsingError+.
+    #
+    # Overriding +#parse+ to call +JSON.parse+ with a single argument
+    # keeps this gem working with both +json+ < 3.0 and +json+ >= 3.0.
+    #
+    # @see https://github.com/dblock/strava-ruby-client/issues/113
+    # @api private
+    #
+    class JsonResponse < ::Faraday::Response::Json
+      private
+
+      def parse(body)
+        return if body.strip.empty?
+
+        ::JSON.parse(body)
+      end
+    end
+  end
+end

spec/strava/web/json_response_spec.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Strava::Web::JsonResponse do
+  let(:middleware) { described_class.new }
+
+  describe '#parse' do
+    it 'parses a JSON object body' do
+      expect(middleware.send(:parse, '{"foo":"bar"}')).to eq('foo' => 'bar')
+    end
+
+    it 'parses a JSON array body' do
+      expect(middleware.send(:parse, '[1,2,3]')).to eq([1, 2, 3])
+    end
+
+    it 'returns nil for an empty body' do
+      expect(middleware.send(:parse, '')).to be_nil
+    end
+
+    it 'returns nil for a blank body' do
+      expect(middleware.send(:parse, '   ')).to be_nil
+    end
+
+    it 'does not raise ArgumentError with json >= 3.0 keyword-only JSON.parse' do
+      expect { middleware.send(:parse, '{}') }.not_to raise_error
+    end
+  end
+end