Handle missing manifest link

lib/manifique/web_client.rb

@@ -12,11 +12,14 @@ module Manifique
       @url = options[:url]
     end
 
-    def fetch_web_manifest
+    def fetch_website
       res = do_get_request @url
-      links = parse_http_link_header(res)
-      doc = Nokogiri::HTML(res.body)
-      manifest_url = discover_web_manifest_url(links, doc)
+      @links = parse_http_link_header(res)
+      @html = Nokogiri::HTML(res.body)
+    end
+
+    def fetch_web_manifest
+      return false unless manifest_url = discover_web_manifest_url(@html)
 
       unless manifest_url.match(/^https?\:\/\//)
         # Link is just the manifest path, not an absolute URL
@@ -25,13 +28,7 @@ module Manifique
 
       res = do_get_request manifest_url
 
-      begin
-        manifest_data = JSON.parse(res.body)
-      rescue
-        manifest_data = false
-      end
-
-      manifest_data
+      JSON.parse(res.body) rescue false
     end
 
     private
@@ -54,12 +51,10 @@ module Manifique
       link_parser.parse(response)
     end
 
-    def discover_web_manifest_url(links, doc)
-      if url = doc.at_css("link[rel=manifest]").attributes["href"].value
-        return url
-      else
-        raise "No Web App Manifest found on #{@url}"
-      end
+    def discover_web_manifest_url(html)
+      html.at_css("link[rel=manifest]").attributes["href"].value
+    rescue
+      false
     end
   end
 end

spec/manifique/web_client_spec.rb

@@ -66,12 +66,36 @@ RSpec.describe Manifique::WebClient do
 
       let(:web_client) { Manifique::WebClient.new(url: "https://kosmos.social") }
 
-      subject { web_client.fetch_web_manifest }
+      subject do
+        web_client.fetch_website
+        web_client.fetch_web_manifest
+      end
 
       it "fetches and returns the manifest" do
         expect(subject).to be_kind_of(Hash)
         expect(subject["name"]).to eq("kosmos.social")
       end
     end
+
+    context "no link[rel=manifest] element found" do
+      before do
+        index_html = File.read(File.join(__dir__, "..", "fixtures", "mastodon-no-manifest.html"));
+        stub_request(:get, "https://kosmos.social/").
+          to_return(body: index_html, status: 200, headers: {
+            "Content-Type": "text/html; charset=utf-8"
+          })
+      end
+
+      let(:web_client) { Manifique::WebClient.new(url: "https://kosmos.social") }
+
+      subject do
+        web_client.fetch_website
+        web_client.fetch_web_manifest
+      end
+
+      it "returns false" do
+        expect(subject).to be(false)
+      end
+    end
   end
 end