Add multipart request support

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2018-08-14 17:57:21 -0400 using RuboCop version 0.56.0.
+# on 2019-10-31 13:05:23 +0200 using RuboCop version 0.56.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -15,11 +15,7 @@ Lint/UnusedMethodArgument:
 
 # Offense count: 2
 Metrics/CyclomaticComplexity:
-  Max: 8
-
-# Offense count: 1
-Metrics/PerceivedComplexity:
-  Max: 8
+  Max: 7
 
 # Offense count: 1
 # Cop supports --auto-correct.
@@ -35,13 +31,13 @@ Style/MethodMissingSuper:
     - 'lib/graphlient/extensions/query.rb'
     - 'lib/graphlient/query.rb'
 
-# Offense count: 5
+# Offense count: 7
 Style/MultilineBlockChain:
   Exclude:
     - 'spec/graphlient/client_query_spec.rb'
     - 'spec/graphlient/client_schema_spec.rb'
 
-# Offense count: 39
+# Offense count: 54
 # Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
 # URISchemes: http, https
 Metrics/LineLength:

README.md

@@ -188,6 +188,21 @@ client.query(input: { fee_in_cents: 12_345 }) do
 end
 ```
 
+### Files support
+
+You can send files while using `FaradayMultipartAdapter`.
+
+```ruby
+client = Graphlient::Client.new('example.com/graphql',
+  http: Graphlient::Adapters::HTTP::FaradayMultipartAdapter
+)
+
+file = File.read('example.txt')
+client.mutation(input: file) # single file
+client.mutation(input: [file]) # files as an array
+client.mutation(input: [{ val: file }]) # files in nested hash
+```
+
 ### Parse and Execute Queries Separately
 
 You can `parse` and `execute` queries separately with optional variables. This is highly recommended as parsing a query and validating a query on every request adds performance overhead. Parsing queries early allows validation errors to be discovered before request time and avoids many potential security issues.

graphlient.gemspec

@@ -17,4 +17,5 @@ Gem::Specification.new do |s|
   s.add_dependency 'faraday'
   s.add_dependency 'faraday_middleware'
   s.add_dependency 'graphql-client'
+  s.add_dependency 'mime-types'
 end

lib/graphlient/adapters/http.rb

@@ -1,3 +1,4 @@
 require_relative 'http/adapter'
 require_relative 'http/faraday_adapter'
+require_relative 'http/faraday_multipart_adapter'
 require_relative 'http/http_adapter'

lib/graphlient/adapters/http/faraday_multipart_adapter.rb

@@ -0,0 +1,42 @@
+require 'faraday'
+require 'faraday_middleware'
+
+module Graphlient
+  module Adapters
+    module HTTP
+      class FaradayMultipartAdapter < Adapter
+        require 'graphlient/adapters/http/faraday_multipart_adapter/format_multipart_variables'
+
+        def execute(document:, operation_name:, variables:, context:)
+          response = connection.post do |req|
+            req.headers.merge!(context[:headers] || {})
+            req.body = {
+              query: document.to_query_string,
+              operationName: operation_name,
+              variables: FormatMultipartVariables.new(variables).call
+            }
+          end
+
+          response.body
+        rescue Faraday::ClientError => e
+          raise Graphlient::Errors::FaradayServerError, e
+        end
+
+        def connection
+          @connection ||= Faraday.new(url: url, headers: headers) do |c|
+            c.use Faraday::Response::RaiseError
+            c.request :multipart
+            c.request :url_encoded
+            c.response :json
+
+            if block_given?
+              yield c
+            else
+              c.use Faraday::Adapter::NetHttp
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/graphlient/adapters/http/faraday_multipart_adapter/format_multipart_variables.rb

@@ -0,0 +1,68 @@
+require 'faraday'
+require 'mime/types'
+require 'graphlient/errors'
+
+module Graphlient
+  module Adapters
+    module HTTP
+      class FaradayMultipartAdapter
+        class NoMimeTypeException < Graphlient::Errors::Error; end
+        # Converts deeply nested File instances to Faraday::UploadIO
+        class FormatMultipartVariables
+          def initialize(variables)
+            @variables = variables
+          end
+
+          def call
+            deep_transform_values(variables) do |variable|
+              variable_value(variable)
+            end
+          end
+
+          private
+
+          attr_reader :variables
+
+          def deep_transform_values(hash, &block)
+            return hash unless hash.is_a?(Hash)
+
+            transform_hash_values(hash) do |val|
+              if val.is_a?(Hash)
+                deep_transform_values(val, &block)
+              else
+                yield(val)
+              end
+            end
+          end
+
+          def variable_value(variable)
+            if variable.is_a?(Array)
+              variable.map { |it| variable_value(it) }
+            elsif variable.is_a?(Hash)
+              transform_hash_values(variable) do |value|
+                variable_value(value)
+              end
+            elsif variable.is_a?(File)
+              file_variable_value(variable)
+            else
+              variable
+            end
+          end
+
+          def file_variable_value(file)
+            content_type = MIME::Types.type_for(file.path).first
+            return Faraday::UploadIO.new(file.path, content_type) if content_type
+
+            raise NoMimeTypeException, "Unable to determine mime type for #{file.path}"
+          end
+
+          def transform_hash_values(hash)
+            hash.each_with_object({}) do |(key, value), result|
+              result[key] = yield(value)
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/graphlient/adapters/http/faraday_multipart_adapter/format_multipart_variables_spec.rb

@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'graphlient/adapters/http/faraday_multipart_adapter/format_multipart_variables'
+
+RSpec.describe Graphlient::Adapters::HTTP::FaradayMultipartAdapter::FormatMultipartVariables do
+  subject(:format_multipart_variables) { described_class.new(variables) }
+
+  describe '#call' do
+    subject(:call) { format_multipart_variables.call }
+
+    context 'when file does not have mime type' do
+      let(:variables) { { val: { file: File.new('/dev/null') } } }
+
+      it 'raises an error' do
+        expect { call }.to raise_error(Graphlient::Adapters::HTTP::FaradayMultipartAdapter::NoMimeTypeException)
+      end
+    end
+
+    context 'when variable is not a file' do
+      let(:variables) { { val: { name: 'John Doe' } } }
+
+      it 'returns correct value' do
+        expect(call).to eq(variables)
+      end
+    end
+
+    context 'when file is deeply nested' do
+      let(:variables) { { val: { file: File.new('spec/support/fixtures/empty.txt') } } }
+
+      it 'contverts file to Faraday::UploadIO' do
+        expect(call[:val][:file]).to be_a(Faraday::UploadIO)
+      end
+    end
+
+    context 'when files are in array' do
+      let(:variables) do
+        {
+          val: [
+            File.new('spec/support/fixtures/empty.txt'),
+            File.new('spec/support/fixtures/empty.txt')
+          ]
+        }
+      end
+
+      it 'contverts file to Faraday::UploadIO' do
+        expect(call[:val]).to all be_a(Faraday::UploadIO)
+      end
+    end
+
+    context 'when file is in array and then nested' do
+      let(:variables) do
+        {
+          val: [
+            { file: File.new('spec/support/fixtures/empty.txt') },
+            { file: File.new('spec/support/fixtures/empty.txt') }
+          ]
+        }
+      end
+
+      it 'converts file to Faraday::UploadIO' do
+        result = call[:val].map { |val| val[:file] }
+        expect(result).to all be_a(Faraday::UploadIO)
+      end
+    end
+  end
+end

spec/graphlient/adapters/http/faraday_multipart_adapter_spec.rb

@@ -0,0 +1,61 @@
+require 'spec_helper'
+
+describe Graphlient::Adapters::HTTP::FaradayMultipartAdapter do
+  let(:app) { Object.new }
+
+  context 'with a custom middleware' do
+    let(:client) do
+      Graphlient::Client.new('http://example.com/graphql', http: described_class) do |client|
+        client.http do |h|
+          h.connection do |c|
+            c.use Faraday::Adapter::Rack, app
+          end
+        end
+      end
+    end
+
+    it 'inserts a middleware into the connection' do
+      expect(client.http.connection.builder.handlers).to eq(
+        [
+          Faraday::Response::RaiseError,
+          Faraday::Request::Multipart,
+          Faraday::Request::UrlEncoded,
+          FaradayMiddleware::ParseJson,
+          Faraday::Adapter::Rack
+        ]
+      )
+    end
+  end
+
+  context 'with custom url and headers' do
+    let(:url) { 'http://example.com/graphql' }
+    let(:headers) { { 'Foo' => 'bar' } }
+    let(:client) do
+      Graphlient::Client.new(url, headers: headers, http: described_class)
+    end
+
+    it 'sets url' do
+      expect(client.http.url).to eq url
+    end
+
+    it 'sets headers' do
+      expect(client.http.headers).to eq headers
+    end
+  end
+
+  context 'default' do
+    let(:url) { 'http://example.com/graphql' }
+    let(:client) { Graphlient::Client.new(url, http: described_class) }
+
+    before do
+      stub_request(:post, url).to_return(
+        status: 200,
+        body: DummySchema.execute(GraphQL::Introspection::INTROSPECTION_QUERY).to_json
+      )
+    end
+
+    it 'retrieves schema' do
+      expect(client.schema).to be_a Graphlient::Schema
+    end
+  end
+end