response buffer: increase coverage, fix buffer dup when tempfile, simplify == as buffer always responds to read

lib/httpx/response/buffer.rb

@@ -29,7 +29,9 @@ module HTTPX
         when StringIO
           StringIO.new(other.buffer.string, mode: File::RDONLY)
         else
-          other.buffer.class.new(other.buffer.path, encoding: Encoding::BINARY, mode: File::RDONLY)
+          other.buffer.class.new(other.buffer.path, encoding: Encoding::BINARY, mode: File::RDONLY).tap do |temp|
+            FileUtils.copy_file(other.buffer.path, temp.path)
+          end
         end
     end
 
@@ -75,22 +77,15 @@ module HTTPX
       super || begin
         return false unless other.is_a?(Response::Buffer)
 
-        if @buffer.nil?
-          other.buffer.nil?
-        elsif @buffer.respond_to?(:read) &&
-              other.respond_to?(:read)
-          buffer_pos = @buffer.pos
-          other_pos = other.buffer.pos
-          @buffer.rewind
-          other.buffer.rewind
-          begin
-            FileUtils.compare_stream(@buffer, other.buffer)
-          ensure
-            @buffer.pos = buffer_pos
-            other.buffer.pos = other_pos
-          end
-        else
-          to_s == other.to_s
+        buffer_pos = @buffer.pos
+        other_pos = other.buffer.pos
+        @buffer.rewind
+        other.buffer.rewind
+        begin
+          FileUtils.compare_stream(@buffer, other.buffer)
+        ensure
+          @buffer.pos = buffer_pos
+          other.buffer.pos = other_pos
         end
       end
     end

test/response_test.rb

@@ -157,6 +157,31 @@ class ResponseTest < Minitest::Test
     assert body.buffer.instance_variable_get(:@buffer).is_a?(Tempfile), "body should buffer to file after going over threshold"
   end
 
+  def test_response_body_dup
+    body = Response::Body.new(Response.new(request, 200, "2.0", {}), Options.new(body_threshold_size: 10))
+    body.extend(Module.new do
+      attr_reader :buffer
+    end)
+    assert body.buffer.nil?, "body should not buffer anything"
+    body.write("hello")
+    body_dup = body.dup
+    body_dup.extend(Module.new do
+      attr_reader :buffer
+    end)
+    assert body.buffer != body_dup.buffer
+    assert body_dup.buffer.instance_variable_get(:@buffer).is_a?(StringIO), "body should buffer to memory"
+    assert body_dup.buffer.instance_variable_get(:@buffer).string == "hello", "body should contain original content"
+
+    body.write(" world")
+    body_dup = body.dup
+    body_dup.extend(Module.new do
+      attr_reader :buffer
+    end)
+    assert body.buffer != body_dup.buffer
+    assert body.buffer.instance_variable_get(:@buffer).is_a?(Tempfile), "body should buffer to file after going over threshold"
+    assert File.read(body_dup.buffer.instance_variable_get(:@buffer)) == "hello world", "body should contain original content"
+  end
+
   def test_response_body_filename
     body = Response::Body.new(Response.new(request, 200, "2.0", {}), Options.new)
     assert body.filename.nil?