Add an EmbedExtractor

This allows us to extract embed codes, their uuids and their types when
given a block of Govspeak.

lib/govspeak.rb

@@ -14,6 +14,8 @@
 require "govspeak/html_validator"
 require "govspeak/html_sanitizer"
 require "govspeak/blockquote_extra_quote_remover"
+require "govspeak/embed_extractor"
+require "govspeak/embedded_content"
 require "govspeak/post_processor"
 require "govspeak/link_extractor"
 require "govspeak/template_renderer"

lib/govspeak/embed_extractor.rb

@@ -0,0 +1,17 @@
+module Govspeak
+  class EmbedExtractor
+    def initialize(document)
+      @document = document
+    end
+
+    def content_references
+      @content_references ||= @document.scan(EmbeddedContent::EMBED_REGEX).map { |match|
+        EmbeddedContent.new(document_type: match[1], content_id: match[2], embed_code: match[0])
+      }.uniq
+    end
+
+    def content_ids
+      @content_ids ||= content_references.map(&:content_id)
+    end
+  end
+end

lib/govspeak/embedded_content.rb

@@ -0,0 +1,15 @@
+module Govspeak
+  class EmbeddedContent
+    SUPPORTED_DOCUMENT_TYPES = %w[contact content_block_email_address].freeze
+    UUID_REGEX = /([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})/
+    EMBED_REGEX = /({{embed:(#{SUPPORTED_DOCUMENT_TYPES.join('|')}):#{UUID_REGEX}}})/
+
+    attr_reader :document_type, :content_id, :embed_code
+
+    def initialize(document_type:, content_id:, embed_code:)
+      @document_type = document_type
+      @content_id = content_id
+      @embed_code = embed_code
+    end
+  end
+end

test/embed_extractor_test.rb

@@ -0,0 +1,59 @@
+require "test_helper"
+
+class EmbedExtractorTest < Minitest::Test
+  extend Minitest::Spec::DSL
+
+  describe "EmbedExtractor" do
+    subject { Govspeak::EmbedExtractor.new(document) }
+
+    describe "when there is no embedded content" do
+      let(:document) { "foo" }
+
+      describe "#content_references" do
+        it "returns an empty array" do
+          assert_equal [], subject.content_references
+        end
+      end
+
+      describe "#content_ids" do
+        it "returns an empty array" do
+          assert_equal [], subject.content_ids
+        end
+      end
+    end
+
+    describe "when there is embedded content" do
+      let(:contact_uuid) { SecureRandom.uuid }
+      let(:content_block_email_address_uuid) { SecureRandom.uuid }
+
+      let(:document) do
+        """
+        {{embed:contact:#{contact_uuid}}}
+        {{embed:content_block_email_address:#{content_block_email_address_uuid}}}
+      """
+      end
+
+      describe "#content_references" do
+        it "returns all references" do
+          result = subject.content_references
+
+          assert_equal 2, result.count
+
+          assert_equal "contact", result[0].document_type
+          assert_equal contact_uuid, result[0].content_id
+          assert_equal "{{embed:contact:#{contact_uuid}}}", result[0].embed_code
+
+          assert_equal "content_block_email_address", result[1].document_type
+          assert_equal content_block_email_address_uuid, result[1].content_id
+          assert_equal "{{embed:content_block_email_address:#{content_block_email_address_uuid}}}", result[1].embed_code
+        end
+      end
+
+      describe "#content_ids" do
+        it "returns all uuids as an array" do
+          assert_equal [contact_uuid, content_block_email_address_uuid], subject.content_ids
+        end
+      end
+    end
+  end
+end