refactor(farady): split up middlewares

lib/scalingo/api/client.rb

@@ -1,6 +1,7 @@
 require "scalingo/token_holder"
 require "scalingo/faraday/response"
-require "scalingo/faraday/unpack_middleware"
+require "scalingo/faraday/extract_meta"
+require "scalingo/faraday/extract_root_value"
 require "active_support/core_ext/hash"
 
 module Scalingo
@@ -87,7 +88,8 @@ def connection(fallback_to_guest: false)
 
       def unauthenticated_connection
         @unauthenticated_conn ||= Faraday.new(connection_options) { |conn|
-          conn.response :unpack
+          conn.response :extract_root_value
+          conn.response :extract_meta
           conn.response :json, content_type: /\bjson$/, parser_options: {symbolize_names: true}
           conn.request :json
 
@@ -108,7 +110,8 @@ def authenticated_connection
         end
 
         @connection = Faraday.new(connection_options) { |conn|
-          conn.response :unpack
+          conn.response :extract_root_value
+          conn.response :extract_meta
           conn.response :json, content_type: /\bjson$/, parser_options: {symbolize_names: true}
           conn.request :json
           conn.request :authorization, "Bearer", -> { token_holder.token&.value }
@@ -122,7 +125,8 @@ def database_connection(database_id)
 
         @database_connections ||= {}
         @database_connections[database_id] ||= Faraday.new(connection_options) { |conn|
-          conn.response :unpack
+          conn.response :extract_root_value
+          conn.response :extract_meta
           conn.response :json, content_type: /\bjson$/, parser_options: {symbolize_names: true}
           conn.request :json
           conn.request :authorization, "Bearer", -> { token_holder.database_tokens[database_id]&.value }

lib/scalingo/faraday/unpack_middleware.rb → lib/scalingo/faraday/extract_meta.rb

@@ -1,12 +1,9 @@
 require "faraday"
 
 module Scalingo
-  class UnpackMiddleware < Faraday::Middleware
+  class ExtractMeta < Faraday::Middleware
     def on_complete(env)
-      # We only want to unpack the response for successful responses
-      return unless env.response.success?
-
-      # Only hash-like objects are relevant to "unpack"
+      # Only hash-like objects are relevant
       return unless env.body.is_a?(Hash)
 
       # Extract meta from response
@@ -23,11 +20,8 @@ def on_complete(env)
           }.compact
         }
       end
-
-      # Dig the root key if it's the only remaining key in the body
-      env.body = env.body.values.first if env.body.size == 1
     end
   end
 end
 
-Faraday::Response.register_middleware(unpack: Scalingo::UnpackMiddleware)
+Faraday::Response.register_middleware(extract_meta: Scalingo::ExtractMeta)

lib/scalingo/faraday/extract_root_value.rb

@@ -0,0 +1,18 @@
+require "faraday"
+
+module Scalingo
+  class ExtractRootValue < Faraday::Middleware
+    def on_complete(env)
+      # We only want to unpack the response for successful responses
+      return unless env.response.success?
+
+      # Only hash-like objects are relevant to "unpack"
+      return unless env.body.is_a?(Hash)
+
+      # Dig the root key if it's the only remaining key in the body
+      env.body = env.body.values.first if env.body.size == 1
+    end
+  end
+end
+
+Faraday::Response.register_middleware(extract_root_value: Scalingo::ExtractRootValue)

lib/scalingo/faraday/response.rb

@@ -1,7 +1,8 @@
 require "faraday"
 require "faraday/response"
 
-# Some additional methods for Faraday::Response in order to enhance expressiveness
+# Note: the file is scalingo/faraday/response but we're reopning Faraday::Response:
+# we define additional methods for Faraday::Response in order to enhance expressiveness
 module Faraday
   class Response
     def client_error?

spec/scalingo/faraday/extract_meta_spec.rb

@@ -0,0 +1,101 @@
+require "spec_helper"
+require "scalingo/faraday/extract_meta"
+
+RSpec.shared_examples "no meta extraction" do
+  it "does not extract meta from response" do
+    expect(subject.meta).to eq(nil)
+    expect(subject.meta?).to eq(false)
+    expect(subject.pagination).to eq(nil)
+    expect(subject.paginated?).to eq(false)
+    expect(subject.cursor_pagination).to eq(nil)
+    expect(subject.cursor_paginated?).to eq(false)
+  end
+end
+
+RSpec.describe Scalingo::ExtractMeta do
+  let(:headers) { {"Content-Type" => content_type}.compact }
+  let(:content_type) { "application/json" }
+  let(:body) { nil }
+
+  let(:client) do
+    Faraday.new do |b|
+      b.response :extract_meta
+      b.response :json, content_type: /\bjson$/, parser_options: {symbolize_names: true}
+      b.adapter :test do |stub|
+        stub.get("/") { [nil, headers, body] }
+      end
+    end
+  end
+
+  subject { client.get("/") }
+
+  context "with a non-json response" do
+    let(:content_type) { "text/html" }
+    let(:body) { "string".to_json }
+
+    include_examples "no meta extraction"
+  end
+
+  context "without a body" do
+    include_examples "no meta extraction"
+  end
+
+  context "with a non indexable body" do
+    let(:body) { "string".to_json }
+
+    include_examples "no meta extraction"
+  end
+
+  context "with a non hash indexable body" do
+    let(:body) { [1, 2, 3].to_json }
+
+    include_examples "no meta extraction"
+  end
+
+  context "with a hash" do
+    context "without a meta key" do
+      let(:body) { {a: 1, b: 2}.to_json }
+
+      include_examples "no meta extraction"
+    end
+
+    context "with a generic meta key" do
+      let(:body) { {meta: {a: 1}}.to_json }
+
+      it "extracts the meta" do
+        expect(subject.meta).to eq({a: 1})
+        expect(subject.meta?).to eq(true)
+        expect(subject.pagination).to eq(nil)
+        expect(subject.paginated?).to eq(false)
+        expect(subject.cursor_pagination).to eq(nil)
+        expect(subject.cursor_paginated?).to eq(false)
+      end
+    end
+
+    context "with a pagination meta key" do
+      let(:body) { {meta: {pagination: {page: 1}}}.to_json }
+
+      it "extracts the meta" do
+        expect(subject.meta).to eq({pagination: {page: 1}})
+        expect(subject.meta?).to eq(true)
+        expect(subject.pagination).to eq({page: 1})
+        expect(subject.paginated?).to eq(true)
+        expect(subject.cursor_pagination).to eq(nil)
+        expect(subject.cursor_paginated?).to eq(false)
+      end
+    end
+
+    context "with a cursor pagination" do
+      let(:body) { {next_cursor: 1, has_more: true}.to_json }
+
+      it "extracts the meta" do
+        expect(subject.meta).to eq({cursor_pagination: {next_cursor: 1, has_more: true}})
+        expect(subject.meta?).to eq(true)
+        expect(subject.pagination).to eq(nil)
+        expect(subject.paginated?).to eq(false)
+        expect(subject.cursor_pagination).to eq({next_cursor: 1, has_more: true})
+        expect(subject.cursor_paginated?).to eq(true)
+      end
+    end
+  end
+end

spec/scalingo/faraday/extract_root_value_spec.rb

@@ -0,0 +1,48 @@
+require "spec_helper"
+require "scalingo/faraday/extract_root_value"
+
+RSpec.describe Scalingo::ExtractRootValue do
+  let(:status) { 200 }
+  let(:body) { {a: 1} }
+
+  let(:client) do
+    Faraday.new do |b|
+      b.response :extract_root_value
+      b.adapter :test do |stub|
+        stub.get("/") { [status, {}, body] }
+      end
+    end
+  end
+
+  subject { client.get("/") }
+
+  context "with a non-successful response" do
+    let(:status) { 300 }
+
+    it "does not change the response body" do
+      expect(subject.body).to eq({a: 1})
+    end
+  end
+
+  context "with a non-hash response" do
+    let(:body) { [{a: 1}] }
+
+    it "does not change the response body" do
+      expect(subject.body).to eq([{a: 1}])
+    end
+  end
+
+  context "with a multi keys hash" do
+    let(:body) { {a: 1, b: 2} }
+
+    it "does not change the response body" do
+      expect(subject.body).to eq({a: 1, b: 2})
+    end
+  end
+
+  context "with a single key hash" do
+    it "extracts the response body" do
+      expect(subject.body).to eq(1)
+    end
+  end
+end