ensure site.data.authors is in the expected format before resolving author meta

lib/jekyll-seo-tag/drop.rb

@@ -239,15 +239,20 @@ module Jekyll
         end
       end
 
+      # Given a string representing the current document's author, return
+      # a normalized hash representing that author. Will try to pull from
+      # site.authors if present and in the proper format.
       def author_hash(author_string)
-        if site.data["authors"] && site.data["authors"][author_string]
-          hash = site.data["authors"][author_string]
-          hash["name"]    ||= author_string
-          hash["twitter"] ||= author_string
-          hash
-        else
-          { "name" => author_string }
-        end
+        site_author_hash(author_string) || { "name" => author_string }
+      end
+
+      def site_author_hash(author_string)
+        return unless site.data["authors"] && site.data["authors"].is_a?(Hash)
+        author_hash = site.data["authors"][author_string]
+        return unless author_hash.is_a?(Hash)
+        author_hash["name"] ||= author_string
+        author_hash["twitter"] ||= author_string
+        author_hash
       end
 
       def seo_name

spec/jekyll_seo_tag/drop_spec.rb

@@ -232,11 +232,11 @@ RSpec.describe Jekyll::SeoTag::Drop do
       end
 
       context "with site.authors as an array" do
-        let("data") { ["foo", "bar"] }
+        let("data") { { "authors" => ["foo", "bar"] } }
         let(:page_meta) { {"author" => "foo"} }
 
         it "doesn't error" do
-          expect(subject.author).to eql("")
+          expect(subject.author).to eql({"name"=>"foo", "twitter"=>"foo"})
         end
       end