Test for Pruner

Gemfile

@@ -1,14 +1,20 @@
 source 'https://rubygems.org'
 
-gem 'sinatra', "~> 2.0"
-gem "retries", "~> 0.0.5"
+gem 'retries', '~> 0.0.5'
+gem 'sinatra', '~> 2.0'
 
-gem "dotenv", "~> 2.5"
+gem 'dotenv', '~> 2.5'
 
-gem "rack-indifferent", "~> 1.2"
+gem 'rack-indifferent', '~> 1.2'
 
-gem "sinatra-router", "~> 0.2.4"
+gem 'sinatra-router', '~> 0.2.4'
 
-gem "rest-client", "~> 2.0"
+gem 'rest-client', '~> 2.0'
 
-gem "sinatra-contrib", "~> 2.0"
+gem 'sinatra-contrib', '~> 2.0'
+
+gem "bogus", "~> 0.1.6"
+
+gem "rake", "~> 12.3"
+
+gem "minitest", "~> 5.11"

Gemfile.lock

@@ -7,7 +7,10 @@ GEM
       minitest (~> 5.1)
       tzinfo (~> 1.1)
     backports (3.11.3)
+    bogus (0.1.6)
+      dependor (>= 0.0.4)
     concurrent-ruby (1.0.5)
+    dependor (1.0.1)
     domain_name (0.5.20180417)
       unf (>= 0.0.5, < 1.0.0)
     dotenv (2.5.0)
@@ -27,6 +30,7 @@ GEM
       rack (>= 1.5)
     rack-protection (2.0.3)
       rack
+    rake (12.3.1)
     rest-client (2.0.2)
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
@@ -59,8 +63,11 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  bogus (~> 0.1.6)
   dotenv (~> 2.5)
+  minitest (~> 5.11)
   rack-indifferent (~> 1.2)
+  rake (~> 12.3)
   rest-client (~> 2.0)
   retries (~> 0.0.5)
   sinatra (~> 2.0)

Rakefile

@@ -0,0 +1,6 @@
+$stdout.sync = true
+
+require 'bundler/setup'
+require 'dotenv/load'
+
+task default: %i[test]

config.ru

@@ -5,5 +5,3 @@ require 'rack/indifferent'
 require_relative 'lib/api/tree.rb'
 
 run Pruning::API::Tree
-
-

lib/api/app.rb

@@ -6,27 +6,26 @@ require_relative '../exceptions'
 
 module Pruning
   module API
+    # Handles general concers regarding API calls
     class App < Sinatra::Base
       before { content_type :json }
       after  { serialise_response }
       set :show_exceptions, true
-      
 
-      error Pruning::Exceptions::UnexpectedError do 
+      error Pruning::Exceptions::UnexpectedError do
         status 500
       end
 
       error Pruning::Exceptions::OriginCannotFindTheResource do
-        status 404     
+        status 404
       end
 
-
       get '/' do
-        "Try /tree/:name"
+        'Try /tree/:name?indicator_ids[]=32&indicator_ids[]=31'
       end
 
-
       private
+
       def serialise_response
         return unless content_type == 'application/json'
         response.body = [JSON(response.body)]

lib/api/tree.rb

@@ -7,17 +7,15 @@ require_relative '../exceptions'
 
 module Pruning
   module API
+    # Handles all tree related API requests
     class Tree < App
       get '/tree/:name' do
-          tree_repo = Pruning::Repos::Tree.new(RestClient, ENV['TREE_SOURCE_API_HOSTNAME'])
-          complete_tree = tree_repo.get(query.name)
-          pruner = Pruning::Processing::Pruner.new(complete_tree)
-          pruner.prune_tree(query.indicator_ids) 
+        tree_repo = Pruning::Repos::Tree.new(RestClient,
+                                             ENV['TREE_SOURCE_API_HOSTNAME'])
+        complete_tree = tree_repo.get(query.name)
+        pruner = Pruning::Processing::Pruner.new(complete_tree)
+        pruner.prune_tree(query.indicator_ids.to_a)
       end
     end
-  end 
+  end
 end
-
-
-
-

lib/exceptions.rb

@@ -4,10 +4,9 @@ module Pruning
     end
 
     class OriginCannotFindTheResource < StandardError
-    end 
+    end
 
     class UnexpectedError < StandardError
     end
   end
 end
-

lib/http/query.rb

@@ -1,5 +1,6 @@
 module Pruning
   module HTTP
+    # Whitelists the URL query parameters
     class Query < Struct.new(:name, :indicator_ids)
       def initialize(params = {})
         symbolised = params.map { |k, v| { k.to_sym => v } }.reduce({}, :merge)
@@ -7,9 +8,9 @@ module Pruning
           value = symbolised.fetch(member, nil)
           next if value.nil?
           case member
-          when :indicator_ids then value.map(&->(indicator_id) { indicator_id.to_i } ) # break on purpose if indicator_ids is not an array
-          when :name then value.to_s.gsub(/[^A-Za-z]/,'') 
-            else value
+          when :indicator_ids then value.map(&->(indicator_id) { indicator_id.to_i }) # break on purpose if indicator_ids is not an array
+          when :name then value.to_s.gsub(/[^A-Za-z]/, '')
+          else value
           end
         end
         super(*values)

lib/pruner.rb

@@ -1,27 +1,29 @@
 module Pruning
   module Processing
+    # Contains methods that store the tree and prune everything 
+    # except the branches with requested indicator 
     class Pruner
-
       def initialize(tree)
         @tree = tree
       end
 
       def prune_tree(indicator_ids)
-        pruned_tree = @tree.dup
+        pruned_tree = @tree
         prune_subtree(pruned_tree, indicator_ids)
         pruned_tree
       end
 
       private
+
       def prune_subtree(nodes, indicator_ids)
         nodes_to_examine = nodes.dup
         nodes_to_examine.each do |node|
-          if indicator_node?(node) 
-            unwanted_indicator = !indicator_ids.include?(node['id'])  
-            nodes.delete(node) if unwanted_indicator 
-          else 
-            has_no_wanted_indicators_in_children = prune_subtree(children(node), indicator_ids)
-            nodes.delete(node) if has_no_wanted_indicators_in_children   
+          if indicator_node?(node)
+            indicator_not_wanted = !indicator_ids.include?(node['id'])
+            nodes.delete(node) if indicator_not_wanted
+          else
+            no_wanted_children = prune_subtree(children(node), indicator_ids)
+            nodes.delete(node) if no_wanted_children
           end
         end
         nodes.empty?
@@ -29,11 +31,11 @@ module Pruning
 
       def children(node)
         node.fetch('sub_themes', false) ||
-        node.fetch('categories', false) || 
-        node.fetch('indicators', false) ||
-        []
+          node.fetch('categories', false) ||
+          node.fetch('indicators', false) ||
+          []
       end
-      
+
       def indicator_node?(node)
         children(node).empty?
       end

lib/repos/tree.rb

@@ -3,31 +3,36 @@ require 'retries'
 require 'json'
 require_relative '../exceptions'
 
+
+NUMBER_OF_RETRIES = 3
+
 module Pruning
   module Repos
+    # Handles communication with origin server
+    # and all its problems
     class Tree
-      def initialize(client=RestClient, base_url)
+      def initialize(client, base_url)
         @client = client
         @base_url = base_url
       end
 
       def get(name)
-        with_retries(max_tries: 3, rescue: [Pruning::Exceptions::ServerErrorOnOrigin]) do
+        with_retries(max_tries: NUMBER_OF_RETRIES, rescue: [Pruning::Exceptions::ServerErrorOnOrigin]) do
           begin
             resp = @client.get(url(name))
-          rescue RestClient::ExceptionWithResponse => e
-            if e.response.code != 404 
-              raise Pruning::Exceptions::ServerErrorOnOrigin
-            else 
-              raise Pruning::Exceptions::OriginCannotFindTheResource
-            end
+              rescue RestClient::ExceptionWithResponse => e
+                raise Pruning::Exceptions::ServerErrorOnOrigin if e.response.code != 404
+                raise Pruning::Exceptions::OriginCannotFindTheResource
+              end
+
+            return JSON(resp.body)
           end
-          return JSON(resp.body)
-        end
-        raise Pruning::Exceptions::UnexpectedError
+          raise Pruning::Exceptions::UnexpectedError
       end
 
-      private 
+
+      private
+
       def url(name)
         "#{@base_url}/tree/#{name}"
       end

rakelib/test.rake

@@ -0,0 +1,5 @@
+require 'rake/testtask'
+
+Rake::TestTask.new do |task|
+  task.pattern = 'test/**/*_test.rb'
+end

test/fixtures/missing_indicators.json

@@ -0,0 +1,47 @@
+[
+  {
+    "id": 1, 
+    "name": "Urban Extent", 
+    "sub_themes": [
+      {
+        "categories": [
+          {
+            "id": 1
+          }, 
+          {
+            "id": 2, 
+            "name": "Population", 
+            "unit": "(thousands)"
+          }, 
+          {
+            "id": 3, 
+            "name": "Population density", 
+            "unit": "(people per sq. km.)"
+          }
+        ], 
+        "id": 1, 
+        "name": "Administrative"
+      }, 
+      {
+        "categories": [
+          {
+            "id": 4, 
+            "name": "Area", 
+            "unit": "(sq. km.)"
+          }, 
+          {
+            "id": 5,
+            "name": "Population", 
+            "unit": "(thousands)"
+          }, 
+          {
+            "id": 6, 
+            "name": "Population density", 
+            "unit": "(people per sq. km.)"
+          }
+        ], 
+        "id": 2, 
+        "name": "Built up"
+      }]
+  }
+]

test/pruner_test.rb

@@ -0,0 +1,61 @@
+require 'minitest/autorun'
+require_relative 'test_helper'
+require_relative '../lib/pruner'
+
+
+class TestPruner < MiniTest::Test
+
+  def test_prune_happy_path
+    correct_tree = json_fixture('fixtures/correct_tree.json')
+    pruner = Pruning::Processing::Pruner.new(correct_tree)
+    tree = pruner.prune_tree([299])
+    expected = [{"id"=>1, "name"=>"Urban Extent",
+                 "sub_themes"=>[{"categories"=>[{"id"=>1,
+                                                 "indicators"=>[{"id"=>299, "name"=>"Total"}],
+                                                 "name"=>"Area",
+                                                 "unit"=>"(sq. km.)"}],
+                                 "id"=>1,
+                                 "name"=>"Administrative"}]}]
+
+    assert_equal(expected, tree)
+  end
+
+  def test_different_top_level_nodes
+    correct_tree = json_fixture('fixtures/correct_tree.json')
+    pruner = Pruning::Processing::Pruner.new(correct_tree)
+    tree = pruner.prune_tree([299, 131])
+    expected = [{"id"=>1, "name"=>"Urban Extent",
+                 "sub_themes"=>[{"categories"=>[{"id"=>1, "indicators"=>[{"id"=>299, "name"=>"Total"}],
+                                                 "name"=>"Area", "unit"=>"(sq. km.)"}], "id"=>1, "name"=>"Administrative"}]},
+                {"id"=>8, "name"=>"Business",
+                 "sub_themes"=>[{"categories"=>[{"id"=>55, "indicators"=>[{"id"=>131, "name"=>"6-9"}],
+                                                 "name"=>"Non-agriculture enterprises by size", "unit"=>"(percent of establishments)"}],
+                                 "id"=>24, "name"=>"Economic census"}]}]
+
+
+    assert_equal(expected, tree)
+  end 
+
+  def test_no_indicators
+    correct_tree = json_fixture('fixtures/correct_tree.json')
+    pruner = Pruning::Processing::Pruner.new(correct_tree)
+    tree = pruner.prune_tree([])
+    assert_equal([], tree)
+  end
+
+
+  def test_with_nonexistant_ids
+    correct_tree = json_fixture('fixtures/correct_tree.json')
+    pruner = Pruning::Processing::Pruner.new(correct_tree)
+    tree = pruner.prune_tree([6000, 7000])
+    assert_equal([], tree)
+  end
+
+  def test_broken_tree
+    missing_indicators_tree = json_fixture('fixtures/missing_indicators.json')
+    pruner = Pruning::Processing::Pruner.new(missing_indicators_tree)
+    tree = pruner.prune_tree([299])
+    assert_equal([], tree)
+  end 
+
+end

test/test_helper.rb

@@ -0,0 +1,19 @@
+ENV['RACK_ENV'] = 'test'
+
+
+require 'bundler/setup'
+require 'dotenv/load'
+require 'json'
+require 'minitest/autorun'
+require 'bogus/minitest/spec'
+
+require_relative '../lib/api/app'
+
+Bogus.configure { |config| config.search_modules << Pruning }
+Thread.abort_on_exception = true
+
+
+def json_fixture(file_name)
+  file = File.read(File.expand_path(File.dirname(__FILE__) + '/' + file_name))
+  JSON.parse(file)
+end