From bf62a7fedbd074479e0efa370fa36ed844c4518a Mon Sep 17 00:00:00 2001
From: Phil Lee <asmega@users.noreply.github.com>
Date: Wed, 30 Nov 2022 10:04:51 +0000
Subject: [PATCH] swap ruby-filemagic for file command

---
 Gemfile                                                   | 2 --
 Gemfile.lock                                              | 2 --
 app/models/forms/bulk_upload_lettings/upload_your_file.rb | 7 ++++++-
 app/models/forms/bulk_upload_sales/upload_your_file.rb    | 7 ++++++-
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/Gemfile b/Gemfile
index a4a56c939..02bcdf3b7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -61,8 +61,6 @@ gem "auto_strip_attributes"
 # Use sidekiq for background processing
 gem "sidekiq"
 
-gem "ruby-filemagic"
-
 group :development, :test do
   # Check gems for known vulnerabilities
   gem "bundler-audit"
diff --git a/Gemfile.lock b/Gemfile.lock
index 082b7874d..b509fb950 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -370,7 +370,6 @@ GEM
       rubocop (~> 1.0)
     rubocop-rspec (2.7.0)
       rubocop (~> 1.19)
-    ruby-filemagic (0.7.3)
     ruby-progressbar (1.11.0)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
@@ -476,7 +475,6 @@ DEPENDENCIES
   rubocop-govuk (= 4.3.0)
   rubocop-performance
   rubocop-rails
-  ruby-filemagic
   selenium-webdriver
   sentry-rails
   sentry-ruby
diff --git a/app/models/forms/bulk_upload_lettings/upload_your_file.rb b/app/models/forms/bulk_upload_lettings/upload_your_file.rb
index 06c7183d1..25e8a73f4 100644
--- a/app/models/forms/bulk_upload_lettings/upload_your_file.rb
+++ b/app/models/forms/bulk_upload_lettings/upload_your_file.rb
@@ -1,3 +1,5 @@
+require "shellwords"
+
 module Forms
   module BulkUploadLettings
     class UploadYourFile
@@ -55,7 +57,10 @@ module Forms
       def validate_file_is_csv
         return unless file
 
-        unless FileMagic.new(FileMagic::MAGIC_MIME).file(file.path).include?("text/csv")
+        argv = %W[file --mime-type -- #{file.path}]
+        output = `#{argv.shelljoin}`
+
+        unless output.include?("text/csv")
           errors.add(:file, :not_csv)
         end
       end
diff --git a/app/models/forms/bulk_upload_sales/upload_your_file.rb b/app/models/forms/bulk_upload_sales/upload_your_file.rb
index 6b5b7a629..3632734ab 100644
--- a/app/models/forms/bulk_upload_sales/upload_your_file.rb
+++ b/app/models/forms/bulk_upload_sales/upload_your_file.rb
@@ -1,3 +1,5 @@
+require "shellwords"
+
 module Forms
   module BulkUploadSales
     class UploadYourFile
@@ -55,7 +57,10 @@ module Forms
       def validate_file_is_csv
         return unless file
 
-        unless FileMagic.new(FileMagic::MAGIC_MIME).file(file.path).include?("text/csv")
+        argv = %W[file --mime-type -- #{file.path}]
+        output = `#{argv.shelljoin}`
+
+        unless output.include?("text/csv")
           errors.add(:file, :not_csv)
         end
       end