diff --git a/test/test_middleware_static.rb b/test/test_middleware_static.rb
index f236894..46ed335 100644
--- a/test/test_middleware_static.rb
+++ b/test/test_middleware_static.rb
@@ -17,8 +17,10 @@ class MiddlewareStaticTest < Minitest::Test
     FileUtils.remove_entry(@root)
   end
 
-  def env_for(path, method: 'GET')
-    { 'REQUEST_METHOD' => method, 'PATH_INFO' => path }
+  def env_for(path, method: 'GET', range: nil)
+    env = { 'REQUEST_METHOD' => method, 'PATH_INFO' => path }
+    env['HTTP_RANGE'] = range if range
+    env
   end
 
   def test_serves_existing_file
@@ -68,4 +70,144 @@ class MiddlewareStaticTest < Minitest::Test
     assert_equal 404, status
     assert_equal 'app: /index.html', body.join
   end
+
+  def test_full_response_advertises_accept_ranges
+    status, headers, = @app.call(env_for('/index.html'))
+    assert_equal 200, status
+    assert_equal 'bytes', headers['Accept-Ranges']
+  end
+
+  def test_serves_a_byte_range_as_206
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+
+    status, headers, body = @app.call(env_for('/data.bin', range: 'bytes=0-3'))
+
+    assert_equal 206, status
+    assert_equal '0123', body.join
+    assert_equal 'bytes 0-3/10', headers['Content-Range']
+    assert_equal '4', headers['Content-Length']
+  end
+
+  def test_serves_a_suffix_range
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+
+    status, headers, body = @app.call(env_for('/data.bin', range: 'bytes=-3'))
+
+    assert_equal 206, status
+    assert_equal '789', body.join
+    assert_equal 'bytes 7-9/10', headers['Content-Range']
+  end
+
+  def test_unsatisfiable_range_returns_416
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+
+    status, headers, body = @app.call(env_for('/data.bin', range: 'bytes=50-60'))
+
+    assert_equal 416, status
+    assert_equal 'bytes */10', headers['Content-Range']
+    assert_equal [], body
+  end
+
+  def test_multi_range_request_falls_back_to_full_200
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+
+    status, _, body = @app.call(env_for('/data.bin', range: 'bytes=0-1,3-4'))
+
+    assert_equal 200, status
+    assert_equal '0123456789', body.join
+  end
+
+  def test_head_request_omits_body_but_reports_full_length
+    status, headers, body = @app.call(env_for('/index.html', method: 'HEAD'))
+
+    assert_equal 200, status
+    assert_equal [], body
+    assert_equal '<h1>static</h1>'.bytesize.to_s, headers['Content-Length']
+  end
+
+  def test_full_response_carries_etag_and_last_modified
+    _status, headers, = @app.call(env_for('/index.html'))
+
+    assert_match(/\AW\/"\d+-\d+"\z/, headers['ETag'])
+    refute_nil headers['Last-Modified']
+  end
+
+  def env_with_header(path, name, value, method: 'GET')
+    env = env_for(path, method: method)
+    env[name] = value
+    env
+  end
+
+  def test_if_none_match_matching_etag_returns_304_without_body
+    _status, headers, = @app.call(env_for('/index.html'))
+    etag = headers['ETag']
+
+    status, headers_304, body = @app.call(env_with_header('/index.html', 'HTTP_IF_NONE_MATCH', etag))
+
+    assert_equal 304, status
+    assert_equal [], body
+    assert_equal etag, headers_304['ETag']
+    assert_nil headers_304['Content-Type']
+    assert_nil headers_304['Content-Length']
+  end
+
+  def test_if_none_match_stale_etag_returns_full_200
+    status, headers, body = @app.call(env_with_header('/index.html', 'HTTP_IF_NONE_MATCH', '"stale"'))
+
+    assert_equal 200, status
+    assert_equal '<h1>static</h1>', body.join
+    refute_nil headers['ETag']
+  end
+
+  def test_if_modified_since_in_the_future_returns_304
+    status, _, body = @app.call(env_with_header('/index.html', 'HTTP_IF_MODIFIED_SINCE', (Time.now + 3600).utc.httpdate))
+
+    assert_equal 304, status
+    assert_equal [], body
+  end
+
+  def test_if_modified_since_in_the_past_returns_full_200
+    status, _, body = @app.call(env_with_header('/index.html', 'HTTP_IF_MODIFIED_SINCE', Time.at(0).utc.httpdate))
+
+    assert_equal 200, status
+    assert_equal '<h1>static</h1>', body.join
+  end
+
+  def test_if_range_with_weak_etag_never_satisfies_so_range_is_ignored
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+    _status, headers, = @app.call(env_for('/data.bin'))
+    weak_etag = headers['ETag']
+
+    env = env_with_header('/data.bin', 'HTTP_IF_RANGE', weak_etag)
+    env['HTTP_RANGE'] = 'bytes=0-3'
+    status, _, body = @app.call(env)
+
+    assert_equal 200, status
+    assert_equal '0123456789', body.join
+  end
+
+  def test_if_range_with_stale_date_falls_back_to_full_200
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+
+    env = env_with_header('/data.bin', 'HTTP_IF_RANGE', Time.at(0).utc.httpdate)
+    env['HTTP_RANGE'] = 'bytes=0-3'
+    status, _, body = @app.call(env)
+
+    assert_equal 200, status
+    assert_equal '0123456789', body.join
+  end
+
+  def test_if_range_with_exact_matching_date_honors_the_range
+    File.write(File.join(@root, 'data.bin'), '0123456789')
+    _status, headers, = @app.call(env_for('/data.bin'))
+    last_modified = headers['Last-Modified']
+
+    env = env_with_header('/data.bin', 'HTTP_IF_RANGE', last_modified)
+    env['HTTP_RANGE'] = 'bytes=0-3'
+    status, headers_206, body = @app.call(env)
+
+    assert_equal 206, status
+    assert_equal '0123', body.join
+    assert_equal 'bytes 0-3/10', headers_206['Content-Range']
+  end
 end
diff --git a/test/test_mime.rb b/test/test_mime.rb
new file mode 100644
index 0000000..58e7819
--- /dev/null
+++ b/test/test_mime.rb
@@ -0,0 +1,53 @@
+require 'minitest/autorun'
+require 'prism'
+
+class MimeTest < Minitest::Test
+  def test_lookup_by_symbol
+    assert_equal 'application/json', Prism::Mime[:json]
+    assert_equal 'text/html', Prism::Mime[:html]
+  end
+
+  def test_unknown_symbol_raises
+    assert_raises(Prism::Mime::UnknownMimeType) { Prism::Mime[:yaml] }
+  end
+
+  def test_known_predicate
+    assert Prism::Mime.known?(:json)
+    refute Prism::Mime.known?(:yaml)
+  end
+
+  def test_symbol_for_content_type_strips_charset
+    assert_equal :json, Prism::Mime.symbol_for_content_type('application/json; charset=utf-8')
+    assert_equal :html, Prism::Mime.symbol_for_content_type('text/html')
+    assert_nil Prism::Mime.symbol_for_content_type('application/octet-stream')
+    assert_nil Prism::Mime.symbol_for_content_type(nil)
+  end
+
+  def test_best_from_accept_picks_highest_q
+    header = 'text/html;q=0.5, application/json;q=0.9, application/xml;q=0.1'
+    assert_equal :json, Prism::Mime.best_from_accept(header)
+  end
+
+  def test_best_from_accept_defaults_q_to_one
+    header = 'application/xml;q=0.5, text/html'
+    assert_equal :html, Prism::Mime.best_from_accept(header)
+  end
+
+  def test_best_from_accept_preserves_order_on_tie
+    header = 'application/xml, application/json'
+    assert_equal :xml, Prism::Mime.best_from_accept(header)
+  end
+
+  def test_best_from_accept_wildcard_defaults_to_html
+    assert_equal :html, Prism::Mime.best_from_accept('*/*')
+  end
+
+  def test_best_from_accept_returns_nil_for_unknown_types_only
+    assert_nil Prism::Mime.best_from_accept('application/octet-stream')
+  end
+
+  def test_best_from_accept_returns_nil_for_blank_header
+    assert_nil Prism::Mime.best_from_accept(nil)
+    assert_nil Prism::Mime.best_from_accept('')
+  end
+end