Merge pull request #3 from akurashev/feature/extract-http-client

Extract HTTP client

.rubocop_todo.yml

@@ -1,16 +1,16 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-11-06 22:43:25 +0300 using RuboCop version 0.76.0.
+# on 2019-11-10 19:31:50 +0300 using RuboCop version 0.76.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
 # Offense count: 2
 Metrics/AbcSize:
-  Max: 26
+  Max: 27
 
-# Offense count: 3
+# Offense count: 4
 # Configuration parameters: CountComments, ExcludedMethods.
 Metrics/MethodLength:
   Max: 23

instagram_tags_searcher.gemspec

@@ -3,7 +3,7 @@
 Gem::Specification.new do |s|
   s.name    = 'instagram_tags_searcher'
   s.summary = 'Searches for Instagram tags related to the given tag'
-  s.version = '0.0.2'
+  s.version = '0.0.3'
   s.authors = ['Andrey Kurashev']
   s.files   = ['lib/instagram_tags_searcher.rb']
 

lib/instagram_tags_searcher.rb

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require 'open-uri'
-require 'json'
 require 'cgi'
 
+require 'instagram_tags_searcher/http_client'
+
 module InstagramTagsSearcher
   def self.search(tag)
     new_tags, codes = from_top(tag)
@@ -40,7 +40,9 @@ def self.search(tag)
 
   def self.from_top(tag)
     tag = CGI.escape(tag)
-    data = fetch_data("https://www.instagram.com/explore/tags/#{tag}/?__a=1")
+    data = HttpClient.new.read_hash(
+      "https://www.instagram.com/explore/tags/#{tag}/?__a=1"
+    )
 
     moretags = []
     codes = []
@@ -66,7 +68,9 @@ def self.from_top(tag)
   end
 
   def self.from_first_comment(code)
-    data = fetch_data("https://www.instagram.com/p/#{code}/?__a=1")
+    data = HttpClient.new.read_hash(
+      "https://www.instagram.com/p/#{code}/?__a=1"
+    )
     comments = data['graphql']['shortcode_media']['edge_media_to_parent_comment']
 
     comments_count = comments['count']
@@ -107,7 +111,7 @@ def self.sort_by_frequency(tags)
   def self.posts_count(tag)
     tag_name = CGI.escape(tag[1..-1])
     url = "https://www.instagram.com/explore/tags/#{tag_name}/?__a=1"
-    data = fetch_data(url)
+    data = HttpClient.new.read_hash(url)
 
     posts = data['graphql']['hashtag']['edge_hashtag_to_media']
     posts['count'].to_i
@@ -118,17 +122,4 @@ def self.search_tags(words)
       word.start_with?('#') && word.count('#') == 1 && word.length > 2
     end
   end
-
-  def self.fetch_data(url)
-    header = {
-      'User-Agent' => 'Mozilla/5.0 (Windows NT 10.0; WOW64) ' \
-                      'AppleWebKit/537.36 (KHTML, like Gecko) ' \
-                      'Chrome/53.0.2785.104 Safari/537.36 Core/1.53.3357.400 ' \
-                      'QQBrowser/9.6.11858.400'
-    }
-
-    response = URI.parse(url).open(header).read
-
-    JSON.parse(response)
-  end
 end

lib/instagram_tags_searcher/http_client.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require 'json'
+require 'open-uri'
+
+module InstagramTagsSearcher
+  # This is a simple HTTP client which relies on Ruby StdLib OpenURI module:
+  # https://ruby-doc.org/stdlib-2.6.3/libdoc/open-uri/rdoc/OpenURI.html
+  #
+  # This wrapper supports custom User-Agent header values.
+  # It expects JSON in response.
+  class HttpClient
+    HEADER = {
+      'User-Agent' => 'Mozilla/5.0 (Windows NT 10.0; WOW64) ' \
+                      'AppleWebKit/537.36 (KHTML, like Gecko) ' \
+                      'Chrome/53.0.2785.104 Safari/537.36 Core/1.53.3357.400 ' \
+                      'QQBrowser/9.6.11858.400'
+    }.freeze
+
+    def read_hash(url)
+      JSON.parse(make_request(url))
+    end
+
+    private
+
+    def make_request(url)
+      URI.parse(url).open(HEADER).read
+    end
+  end
+end