Use charlock_holmes instead of nkf at FetchLinkCardService (#4080)

* Specs for language detection * Use CharlockHolmes instead of NKF * Correct mistakes * Correct style * Set hint_enc instead of falling back and strip_tags * Improve specs * Add dependencies

Use charlock_holmes instead of nkf at FetchLinkCardService (#4080)
007ab330 · nullkal · Eugen Rochko · 794781d1 · 007ab330 · 007ab330
--- a/.travis.yml
+++ b/.travis.yml
@@ -32,6 +32,7 @@ addons:
    - g++-6
    - libprotobuf-dev
    - protobuf-compiler
+    - libicu-dev

 rvm:
  - 2.3.4

--- a/Aptfile
+++ b/Aptfile
@@ -3,3 +3,4 @@ libprotobuf-dev
 ffmpeg
 libxdamage1
 libxfixes3
+libicu-dev
--- a/Dockerfile
+++ b/Dockerfile
@@ -25,6 +25,7 @@ RUN echo "@edge https://nl.alpinelinux.org/alpine/edge/main" >> /etc/apk/reposit
    ffmpeg \
    file \
    git \
+    icu-dev \
    imagemagick@edge \
    libpq \
    libxml2 \

--- a/Gemfile
+++ b/Gemfile
@@ -22,6 +22,7 @@ gem 'active_model_serializers', '~> 0.10'
 gem 'addressable', '~> 2.5'
 gem 'bootsnap'
 gem 'browser'
+gem 'charlock_holmes', '~> 0.7.3'
 gem 'cld3', '~> 3.1'
 gem 'devise', '~> 4.2'
 gem 'devise-two-factor', '~> 3.0'

--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -106,6 +106,7 @@ GEM
      rack (>= 1.0.0)
      rack-test (>= 0.5.4)
      xpath (~> 2.0)
+    charlock_holmes (0.7.3)
    case_transform (0.2)
      activesupport
    chunky_png (1.3.8)
@@ -501,6 +502,7 @@ DEPENDENCIES
  capistrano-rbenv (~> 2.1)
  capistrano-yarn (~> 2.0)
  capybara (~> 2.14)
+  charlock_holmes (~> 0.7.3)
  cld3 (~> 3.1)
  climate_control (~> 0.2)
  devise (~> 4.2)

--- a/Vagrantfile
+++ b/Vagrantfile
@@ -37,6 +37,7 @@ sudo apt-get install \
  yarn \
  libprotobuf-dev \
  libreadline-dev \
+  libicu-dev \
  -y

 # Install rvm

--- a/app/services/fetch_link_card_service.rb
+++ b/app/services/fetch_link_card_service.rb
 # frozen_string_literal: true
-require 'nkf'

 class FetchLinkCardService < BaseService
  include HttpHelper
@@ -86,7 +85,12 @@ class FetchLinkCardService < BaseService
    return if response.code != 200 || response.mime_type != 'text/html'

    html = response.to_s
-    page = Nokogiri::HTML(html, nil, NKF.guess(html).to_s)
+
+    detector = CharlockHolmes::EncodingDetector.new
+    detector.strip_tags = true
+
+    guess = detector.detect(html, response.charset)
+    page = Nokogiri::HTML(html, nil, guess&.fetch(:encoding))

    card.type             = :link
    card.title            = meta_property(page, 'og:title') || page.at_xpath('//title')&.content

--- a/spec/fixtures/requests/koi8-r.txt
+++ b/spec/fixtures/requests/koi8-r.txt
+HTTP/1.1 200 OK
+Server: nginx/1.11.10
+Date: Tue, 04 Jul 2017 16:43:39 GMT
+Content-Type: text/html
+Content-Length: 273
+Connection: keep-alive
+Last-Modified: Tue, 04 Jul 2017 16:41:34 GMT
+Accept-Ranges: bytes
+
+<HTML>
+<HEAD>
+  <META NAME="GENERATOR" CONTENT="Adobe PageMill 3.0J Mac">
+  <META HTTP-EQUIV="Content-Type" CONTENT="text/html;CHARSET=koi8-r">
+  <TITLE>    XVI .   .</TITLE>
+</HEAD>
+<BODY>
+<P><CENTER><B><FONT SIZE="+2">    XVI .   .</FONT></B><BR>
+<HR><BR>
+</BODY>
+</HTML>
--- a/spec/fixtures/requests/sjis.txt
+++ b/spec/fixtures/requests/sjis.txt
@@ -11,10 +11,10 @@ Accept-Ranges: bytes
 <HEAD>
  <META NAME="GENERATOR" CONTENT="Adobe PageMill 3.0J Mac">
  <META HTTP-EQUIV="Content-Type" CONTENT="text/html;CHARSET=x-sjis">
-  <TITLE>JSIS̃y[W</TITLE>
+  <TITLE>SJISのページ</TITLE>
 </HEAD>
 <BODY>
-<P><CENTER><B><FONT SIZE="+2">SJIS̃y[W</FONT></B><BR>
+<P><CENTER><B><FONT SIZE="+2">私も同年ましていわゆる記念人ってものの時でしありです。もし時間に意味者は正しくどんな発会ませだまでが申し上げがいらっしゃるたには参考帰るたいだから、少しにもやっあっましなた。金からいうないのはどうも九月をできるだけたたくた。けっして岡田さんに反抗幸少し徴に云おでしょ金力こうした権力あなたか指図がというお出入りなくだろなありて、その昔は私か金力陰を怒らから、久原さんのものをがたのいつがしかるにご希望と向いばそれmanにご矛盾へ参りように同時にご演説がしでならので、多分もし表裏に変ったてくれです事で考えたた。しかも例えばごがたがとどまらものも実際むやみとありですて、この自分では申しんてとして世間に並べのに行かなかっな。</FONT></B><BR>
 <HR><BR>
 </BODY>
 </HTML>
--- a/spec/fixtures/requests/sjis_with_wrong_charset.txt
+++ b/spec/fixtures/requests/sjis_with_wrong_charset.txt
+HTTP/1.1 200 OK
+Server: nginx/1.11.10
+Date: Tue, 04 Jul 2017 16:43:39 GMT
+Content-Type: text/html; charset=utf-8
+Content-Length: 273
+Connection: keep-alive
+Last-Modified: Tue, 04 Jul 2017 16:41:34 GMT
+Accept-Ranges: bytes
+
+<HTML>
+<HEAD>
+  <META NAME="GENERATOR" CONTENT="Adobe PageMill 3.0J Mac">
+  <META HTTP-EQUIV="Content-Type" CONTENT="text/html;CHARSET=x-sjis">
+  <TITLE>SJISのページ</TITLE>
+</HEAD>
+<BODY>
+<P><CENTER><B><FONT SIZE="+2">私も同年ましていわゆる記念人ってものの時でしありです。もし時間に意味者は正しくどんな発会ませだまでが申し上げがいらっしゃるたには参考帰るたいだから、少しにもやっあっましなた。金からいうないのはどうも九月をできるだけたたくた。けっして岡田さんに反抗幸少し徴に云おでしょ金力こうした権力あなたか指図がというお出入りなくだろなありて、その昔は私か金力陰を怒らから、久原さんのものをがたのいつがしかるにご希望と向いばそれmanにご矛盾へ参りように同時にご演説がしでならので、多分もし表裏に変ったてくれです事で考えたた。しかも例えばごがたがとどまらものも実際むやみとありですて、この自分では申しんてとして世間に並べのに行かなかっな。</FONT></B><BR>
+<HR><BR>
+</BODY>
+</HTML>
--- a/spec/services/fetch_link_card_service_spec.rb
+++ b/spec/services/fetch_link_card_service_spec.rb
@@ -8,6 +8,10 @@ RSpec.describe FetchLinkCardService do
    stub_request(:get, 'http://example.xn--fiqs8s/').to_return(request_fixture('idn.txt'))
    stub_request(:head, 'http://example.com/sjis').to_return(status: 200, headers: { 'Content-Type' => 'text/html' })
    stub_request(:get, 'http://example.com/sjis').to_return(request_fixture('sjis.txt'))
+    stub_request(:head, 'http://example.com/sjis_with_wrong_charset').to_return(status: 200, headers: { 'Content-Type' => 'text/html' })
+    stub_request(:get, 'http://example.com/sjis_with_wrong_charset').to_return(request_fixture('sjis_with_wrong_charset.txt'))
+    stub_request(:head, 'http://example.com/koi8-r').to_return(status: 200, headers: { 'Content-Type' => 'text/html' })
+    stub_request(:get, 'http://example.com/koi8-r').to_return(request_fixture('koi8-r.txt'))
    stub_request(:head, 'https://github.com/qbi/WannaCry').to_return(status: 404)

    subject.call(status)
@@ -27,6 +31,25 @@ RSpec.describe FetchLinkCardService do

      it 'works with SJIS' do
        expect(a_request(:get, 'http://example.com/sjis')).to have_been_made.at_least_once
+        expect(status.preview_card.title).to eq("SJISのページ")
+      end
+    end
+
+    context do
+      let(:status) { Fabricate(:status, text: 'Check out http://example.com/sjis_with_wrong_charset') }
+
+      it 'works with SJIS even with wrong charset header' do
+        expect(a_request(:get, 'http://example.com/sjis_with_wrong_charset')).to have_been_made.at_least_once
+        expect(status.preview_card.title).to eq("SJISのページ")
+      end
+    end
+
+    context do
+      let(:status) { Fabricate(:status, text: 'Check out http://example.com/koi8-r') }
+
+      it 'works with koi8-r' do
+        expect(a_request(:get, 'http://example.com/koi8-r')).to have_been_made.at_least_once
+        expect(status.preview_card.title).to eq("Московя начинаетъ только въ XVI ст. привлекать внимане иностранцевъ.")
      end
    end
  end