Use MiniMime for MIME type lookup by filename/extension

Co-authored-by: John Hawthorn <john@hawthorn.email>

Gemfile.lock

@@ -3,11 +3,13 @@ PATH
   specs:
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
+      mini_mime (~> 1.0.2)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    mimemagic (0.3.2)
+    mimemagic (0.3.6)
+    mini_mime (1.0.2)
     minitest (5.11.3)
     rack (2.1.4)
     rake (13.0.1)
@@ -23,4 +25,4 @@ DEPENDENCIES
   rake (~> 13.0)
 
 BUNDLED WITH
-   1.16.4
+   1.17.2

lib/marcel/mime_type.rb

@@ -1,7 +1,15 @@
+require "mini_mime"
+
 class Marcel::MimeType
   BINARY = "application/octet-stream"
 
+  @ext_overrides = {}
+
+  OverrideInfo = Struct.new(:content_type)
+
   class << self
+    attr_reader :ext_overrides
+
     def extend(type, extensions: [], parents: [], magic: nil)
       existing = MimeMagic::TYPES[type] || [[], [], ""]
 
@@ -10,6 +18,12 @@ def extend(type, extensions: [], parents: [], magic: nil)
       comment = existing[2]
 
       MimeMagic.add(type, extensions: extensions, magic: magic, parents: parents, comment: comment)
+
+      info = MiniMime.lookup_by_content_type(type)
+      info ||= OverrideInfo.new(type)
+      extensions.each do |ext|
+        @ext_overrides[ext] = info
+      end
     end
 
     def for(pathname_or_io = nil, name: nil, extension: nil, declared_type: nil)
@@ -36,16 +50,18 @@ def for_data(pathname_or_io)
 
       def for_name(name)
         if name
-          if magic = MimeMagic.by_path(name)
-            magic.type.downcase
-          end
+          extension = File.extname(name)
+          return if extension.empty?
+          for_extension(extension)
         end
       end
 
       def for_extension(extension)
         if extension
-          if magic = MimeMagic.by_extension(extension)
-            magic.type.downcase
+          extension = extension.gsub(/\A\./, "").downcase
+
+          if info = (Marcel::MimeType.ext_overrides[extension] || MiniMime.lookup_by_extension(extension))
+            info.content_type.downcase
           end
         end
       end

lib/marcel/mime_type/definitions.rb

@@ -37,3 +37,12 @@
 
 Marcel::MimeType.extend "image/heif", magic: [[4, "ftypmif1"]], extensions: %w( heif )
 Marcel::MimeType.extend "image/heic", magic: [[4, "ftypheic"]], extensions: %w( heic )
+
+# Backwards compat overrides from MiniMime migration
+Marcel::MimeType.extend "text/x-log", extensions: %w( log )
+Marcel::MimeType.extend "application/sql", extensions: %w( sql )
+Marcel::MimeType.extend "audio/flac", extensions: %w( flac )
+Marcel::MimeType.extend "image/x-eps", extensions: %w( eps )
+Marcel::MimeType.extend "video/mp4", extensions: %w( mp4 )
+Marcel::MimeType.extend "image/bmp", extensions: %w( bmp )
+Marcel::MimeType.extend "application/vnd.adobe.flash.movie", extensions: %w( swf )

marcel.gemspec

@@ -20,6 +20,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 2.2'
 
   spec.add_dependency 'mimemagic', '~> 0.3.2'
+  spec.add_dependency 'mini_mime', '~> 1.0.2'
 
   spec.add_development_dependency 'minitest', '~> 5.11'
   spec.add_development_dependency 'bundler', '>= 1.7'