Merge pull request #13 from alphagov/add-test-helper

Add test helper

Author: AgaDufrat

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.2.0
+
+* Add test helpers which provide stubs
+
 ## 1.1.2
 
 * Update dependencies

README.md

@@ -86,6 +86,10 @@ loader = GovukGraphql::ConditionalContentItemLoader.new(
 
 The decision logic is also exposed via `can_load_from_graphql?`, allowing applications to make the routing decision themselves and implement custom fallback or error-handling behaviour if needed.
 
+## Test helpers
+
+There are also test helpers for stubbing responses in other apps. See [lib/test_helpers.rb](/lib/test_helpers.rb).
+
 ## Licence
 
 The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).

lib/govuk_content_item_loader.rb

@@ -1,3 +1,4 @@
 require "govuk_content_item_loader/govuk_graphql_traffic_rates"
 require "govuk_content_item_loader/govuk_conditional_content_item_loader"
 require "govuk_content_item_loader/version"
+require "govuk_content_item_loader/test_helpers"

lib/govuk_content_item_loader/test_helpers.rb

@@ -0,0 +1,58 @@
+require "json"
+
+module GovukConditionalContentItemLoaderTestHelpers
+  Response = Struct.new(:status, :body, :headers) do
+    def to_h
+      JSON.parse(body)
+    end
+  end
+
+  # Stubs the loader returns a content item
+  # The following options can be passed in:
+  #
+  #   :max_age  will set the max-age of the Cache-Control header in the response. Defaults to 900
+  #   :private  if true, the Cache-Control header will include the "private" directive. By default it
+  #             will include "public"
+  def stub_conditional_loader_returns_content_item(body, options = {})
+    body.to_json unless body.is_a?(String)
+    max_age = options.fetch(:max_age, 900)
+    visibility = options[:private] ? "private" : "public"
+
+    response = Response.new(200, body, {
+      cache_control: "#{visibility}, max-age=#{max_age}",
+      date: Time.now.httpdate,
+    })
+
+    loader = instance_double(GovukConditionalContentItemLoader, load: response)
+
+    allow(GovukConditionalContentItemLoader).to receive(:new).with(request: anything)
+      .and_return(loader)
+    allow(loader).to receive(:load).and_return(body)
+
+    response
+  end
+
+  # Stubs the loader returns a error response
+  # The following options can be passed in:
+  #
+  #   :status         the HTTP status code for the error. Defaults to 404
+  #   :message        the error message. Defaults to "Not Found"
+  #   :error_details  optional additional error details to attach to the exception
+  #   :http_body      optional raw response body to attach to the exception
+  def stub_conditional_loader_does_not_return_content_item(options = {})
+    status = options.fetch(:status, 404)
+    message = options.fetch(:message, "Not Found")
+    error_details = options[:error_details]
+    http_body = options[:http_body]
+
+    error = GdsApi::HTTPErrorResponse.new(status, message, error_details, http_body)
+
+    loader = instance_double(GovukConditionalContentItemLoader)
+
+    allow(GovukConditionalContentItemLoader).to receive(:new).with(request: anything)
+      .and_return(loader)
+    allow(loader).to receive(:load).and_raise(error)
+
+    error
+  end
+end

lib/govuk_content_item_loader/version.rb

@@ -1,3 +1,3 @@
 module GovukContentItemLoader
-  VERSION = "1.1.2".freeze
+  VERSION = "1.2.0".freeze
 end