Add raise_on_missing_assets and exceptions on missing assets

README.md

@@ -201,6 +201,7 @@ class ThingsController < ApplicationController
                viewport_size:                  'TEXT',                    # available only with use_xserver or patched QT
                extra:                          '',                        # directly inserted into the command to wkhtmltopdf
                raise_on_all_errors:            nil,                       # raise error for any stderr output.  Such as missing media, image assets
+               raise_on_missing_assets:        nil,                       # raise when trying to access a missing asset
                log_level:                      'info',                    # Available values: none, error, warn, or info - only available with wkhtmltopdf 0.12.5+
                quiet:                          false,                     # `false` is same as `log_level: 'info'`, `true` is same as `log_level: 'none'`
                outline: {   outline:           true,

lib/wicked_pdf/wicked_pdf_helper/assets.rb

@@ -7,6 +7,27 @@ module WickedPdfHelper
     module Assets
       ASSET_URL_REGEX = /url\(['"]?([^'"]+?)['"]?\)/
 
+      class MissingAsset < StandardError; end
+
+      class MissingLocalAsset < MissingAsset
+        attr_reader :path
+
+        def initialize(path)
+          @path = path
+          super("Could not find asset '#{path}'")
+        end
+      end
+
+      class MissingRemoteAsset < MissingAsset
+        attr_reader :url, :response
+
+        def initialize(url, response)
+          @url = url
+          @response = response
+          super("Could not fetch asset '#{url}': server responded with #{response.code} #{response.message}")
+        end
+      end
+
       class PropshaftAsset < SimpleDelegator
         def content_type
           super.to_s
@@ -21,9 +42,39 @@ def filename
         end
       end
 
+      class SprocketsEnvironment
+        def self.instance
+          @instance ||= Sprockets::Railtie.build_environment(Rails.application)
+        end
+
+        def self.find_asset(*args)
+          instance.find_asset(*args)
+        end
+      end
+
+      class LocalAsset
+        attr_reader :path
+
+        def initialize(path)
+          @path = path
+        end
+
+        def content_type
+          Mime::Type.lookup_by_extension(File.extname(path).delete('.'))
+        end
+
+        def to_s
+          IO.read(path)
+        end
+
+        def filename
+          path.to_s
+        end
+      end
+
       def wicked_pdf_asset_base64(path)
         asset = find_asset(path)
-        raise "Could not find asset '#{path}'" if asset.nil?
+        raise MissingLocalAsset, path if asset.nil?
 
         base64 = Base64.encode64(asset.to_s).gsub(/\s+/, '')
         "data:#{asset.content_type};base64,#{Rack::Utils.escape(base64)}"
@@ -150,8 +201,11 @@ def find_asset(path)
           Rails.application.assets.find_asset(path, :base_path => Rails.application.root.to_s)
         elsif defined?(Propshaft::Assembly) && Rails.application.assets.is_a?(Propshaft::Assembly)
           PropshaftAsset.new(Rails.application.assets.load_path.find(path))
+        elsif Rails.application.respond_to?(:assets_manifest)
+          asset_path = File.join(Rails.application.assets_manifest.dir, Rails.application.assets_manifest.assets[path])
+          LocalAsset.new(asset_path) if File.file?(asset_path)
         else
-          Sprockets::Railtie.build_environment(Rails.application).find_asset(path, :base_path => Rails.application.root.to_s)
+          SprocketsEnvironment.find_asset(path, :base_path => Rails.application.root.to_s)
         end
       end
 
@@ -175,20 +229,35 @@ def precompiled_or_absolute_asset?(source)
       end
 
       def read_asset(source)
-        if precompiled_or_absolute_asset?(source)
-          pathname = asset_pathname(source)
-          if pathname =~ URI_REGEXP
-            read_from_uri(pathname)
-          elsif File.file?(pathname)
-            IO.read(pathname)
-          end
-        else
-          find_asset(source).to_s.force_encoding('UTF-8')
+        asset = find_asset(source)
+        return asset.to_s.force_encoding('UTF-8') if asset
+
+        unless precompiled_or_absolute_asset?(source)
+          raise MissingLocalAsset, source if WickedPdf.config[:raise_on_missing_assets]
+
+          return
+        end
+
+        pathname = asset_pathname(source)
+        if pathname =~ URI_REGEXP
+          read_from_uri(pathname)
+        elsif File.file?(pathname)
+          IO.read(pathname)
+        elsif WickedPdf.config[:raise_on_missing_assets]
+          raise MissingLocalAsset, pathname if WickedPdf.config[:raise_on_missing_assets]
         end
       end
 
       def read_from_uri(uri)
-        asset = Net::HTTP.get(URI(uri))
+        response = Net::HTTP.get_response(URI(uri))
+
+        unless response.is_a?(Net::HTTPSuccess)
+          raise MissingRemoteAsset.new(uri, response) if WickedPdf.config[:raise_on_missing_assets]
+
+          return
+        end
+
+        asset = response.body
         asset.force_encoding('UTF-8') if asset
         asset = gzip(asset) if WickedPdf.config[:expect_gzipped_remote_assets]
         asset

test/functional/wicked_pdf_helper_assets_test.rb

@@ -4,6 +4,15 @@
 class WickedPdfHelperAssetsTest < ActionView::TestCase
   include WickedPdf::WickedPdfHelper::Assets
 
+  setup do
+    @saved_config = WickedPdf.config
+    WickedPdf.config = {}
+  end
+
+  teardown do
+    WickedPdf.config = @saved_config
+  end
+
   if Rails::VERSION::MAJOR > 3 || (Rails::VERSION::MAJOR == 3 && Rails::VERSION::MINOR > 0)
     test 'wicked_pdf_asset_base64 returns a base64 encoded asset' do
       assert_match %r{data:text\/css;base64,.+}, wicked_pdf_asset_base64('wicked.css')
@@ -15,6 +24,58 @@ class WickedPdfHelperAssetsTest < ActionView::TestCase
                    wicked_pdf_stylesheet_link_tag('wicked')
     end
 
+    test 'wicked_pdf_stylesheet_link_tag should raise if the stylesheet is not available and config is set' do
+      Rails.configuration.assets.expects(:compile => true)
+      WickedPdf.config[:raise_on_missing_assets] = true
+      assert_raise WickedPdf::WickedPdfHelper::Assets::MissingLocalAsset do
+        wicked_pdf_stylesheet_link_tag('non_existent')
+      end
+    end
+
+    test 'wicked_pdf_stylesheet_link_tag should return empty if the stylesheet is not available' do
+      Rails.configuration.assets.expects(:compile => true)
+      assert_equal "<style type='text/css'></style>",
+                   wicked_pdf_stylesheet_link_tag('non_existent')
+    end
+
+    test 'wicked_pdf_stylesheet_link_tag should raise if the absolute path stylesheet is not available and config is set' do
+      Rails.configuration.assets.expects(:compile => true)
+      WickedPdf.config[:raise_on_missing_assets] = true
+      expects(:precompiled_or_absolute_asset? => true).twice
+      assert_raise WickedPdf::WickedPdfHelper::Assets::MissingLocalAsset do
+        wicked_pdf_stylesheet_link_tag('/non_existent')
+      end
+    end
+
+    test 'wicked_pdf_stylesheet_link_tag should return empty if the absolute path stylesheet is not available' do
+      Rails.configuration.assets.expects(:compile => true).twice
+      assert_equal "<style type='text/css'></style>",
+                   wicked_pdf_stylesheet_link_tag('/non_existent')
+    end
+
+    test 'wicked_pdf_stylesheet_link_tag should inline the stylesheets passed in when assets are remote' do
+      stub_request(:get, 'https://www.example.com/wicked.css').to_return(:status => 200, :body => '/* Wicked styles */')
+      expects(:precompiled_or_absolute_asset? => true).twice
+      assert_equal "<style type='text/css'>/* Wicked styles */</style>",
+                   wicked_pdf_stylesheet_link_tag('https://www.example.com/wicked.css')
+    end
+
+    test 'wicked_pdf_stylesheet_link_tag should raise if remote assets are not available and config is set' do
+      WickedPdf.config[:raise_on_missing_assets] = true
+      stub_request(:get, 'https://www.example.com/wicked.css').to_return(:status => 404, :body => 'File not found')
+      expects(:precompiled_or_absolute_asset? => true).twice
+      assert_raise WickedPdf::WickedPdfHelper::Assets::MissingRemoteAsset do
+        wicked_pdf_stylesheet_link_tag('https://www.example.com/wicked.css')
+      end
+    end
+
+    test 'wicked_pdf_stylesheet_link_tag should return empty if remote assets are not available' do
+      stub_request(:get, 'https://www.example.com/wicked.css').to_return(:status => 404, :body => 'File not found')
+      expects(:precompiled_or_absolute_asset? => true).twice
+      assert_equal "<style type='text/css'></style>",
+                   wicked_pdf_stylesheet_link_tag('https://www.example.com/wicked.css')
+    end
+
     test 'wicked_pdf_image_tag should return the same as image_tag when passed a full path' do
       Rails.configuration.assets.expects(:compile => true)
       assert_equal image_tag("file:///#{Rails.root.join('public', 'pdf')}"),

test/test_helper.rb

@@ -7,6 +7,7 @@
 require 'mocha'
 require 'rails/test_help'
 require 'mocha/test_unit'
+require 'webmock/minitest'
 
 require 'wicked_pdf'
 

wicked_pdf.gemspec

@@ -37,4 +37,5 @@ DESC
   spec.add_development_dependency 'rubocop', '~> 1.46'
   spec.add_development_dependency 'sqlite3', '~> 1.3'
   spec.add_development_dependency 'test-unit'
+  spec.add_development_dependency 'webmock', '~> 3.19'
 end