Cache token authentication auth hash parsing

This will cache the parsing and creation/updating of the database when
fetching a user by API token.

The calls to the remote server still happen, however the etag header
will be inspected and used to determine if we have a cached copy of the
user model.

Author: csexton

lib/kracken/authenticator.rb

@@ -1,6 +1,6 @@
 module Kracken
   class Authenticator
-    attr_reader :auth_hash, :user_class
+    attr_reader :auth_hash
 
     ## Factory Methods
 
@@ -14,8 +14,11 @@ def self.user_with_credentials(email, password)
     # Login the user with an auth token. Used for API authentication for the
     # public APIs
     def self.user_with_token(token)
-      response = Kracken::TokenAuthenticator.new.fetch(token)
-      response ? self.new(response).to_app_user : nil
+      auth = Kracken::TokenAuthenticator.new.fetch(token)
+
+      Rails.cache.fetch("auth/#{token}/#{auth.etag}") do
+        self.new(auth.body).to_app_user
+      end
     end
 
     def initialize(response)

lib/kracken/token_authenticator.rb

@@ -1,22 +1,29 @@
 module Kracken
   class TokenAuthenticator
-
+    attr_reader :response
     def fetch(token)
-      response = connection.get do |req|
+      @response = connection.get do |req|
         req.url '/auth/radius/user.json'
         req.params['oauth_token'] = token
       end
 
-      # An attempt to raise error when approprate:
-      if response.status == 404
-        nil
-      elsif response.status == 401
+      if response.status == 401
+        raise TokenUnauthorized, "Invalid credentials"
+      elsif response.status == 404
         raise TokenUnauthorized, "Invalid credentials"
-      elsif response.success?
-        JSON.parse(response.body)
-      else
-        raise Kracken::RequestError
+      elsif !response.success?
+        raise RequestError
       end
+
+      self
+    end
+
+    def body
+      JSON.parse(response.body)
+    end
+
+    def etag
+      response.headers["etag"]
     end
 
     private

spec/dummy/config/environments/test.rb

@@ -1,5 +1,6 @@
 Dummy::Application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
+  config.cache_store = :null_store
 
   # The test environment is used exclusively to run your application's
   # test suite. You never need to work with it otherwise. Remember that

spec/kracken/authenticator_spec.rb

@@ -32,31 +32,30 @@ module Kracken
     end
 
     describe ".with_token" do
-      it "returns nil when nothing is found" do
-        expect_any_instance_of(TokenAuthenticator)
-          .to receive(:fetch)
-          .and_return(nil)
-
-        expect(Authenticator.user_with_token("secret")).to be_nil
-      end
+      let(:token_auth) {
+        object_double(
+          TokenAuthenticator.new,
+          etag: "etag",
+          body: { 'uid' => 1 }
+        )
+      }
 
       it "creates a user using the user_class" do
         expect_any_instance_of(TokenAuthenticator)
           .to receive(:fetch)
-          .and_return({'uid' => 1})
+          .and_return(token_auth)
 
         expect(Authenticator.user_with_token("secret").class).to eq User
       end
 
       it "sets the user's uid" do
         expect_any_instance_of(TokenAuthenticator)
           .to receive(:fetch)
-          .and_return({'uid' => 1})
+          .with("secret")
+          .and_return(token_auth)
 
         expect(Authenticator.user_with_token("secret").uid).to eq 1
       end
     end
-
-
   end
 end

spec/kracken/token_authenticator_spec.rb

@@ -14,7 +14,7 @@ def set_request(status, body=nil)
       set_request 200, json
 
       response = login.fetch "secret"
-      expect(response['uid']).to eq "1"
+      expect(response.body['uid']).to eq "1"
     end
 
     it "raises an error on 500" do
@@ -30,7 +30,7 @@ def set_request(status, body=nil)
 
       set_request 404
 
-      expect(login.fetch "secret").to be_nil
+      expect{login.fetch "secret"}.to raise_error(TokenUnauthorized)
     end
 
   end