fix: Fixed exception when decoding from a rack source that uses InputWrapper (#50)

Signed-off-by: Daniel Azuma <[email protected]>

Author: dazuma

Gemfile

@@ -5,5 +5,6 @@ gem "google-style", "~> 1.25.1"
 gem "minitest", "~> 5.14"
 gem "minitest-focus", "~> 1.1"
 gem "minitest-rg", "~> 5.2"
+gem "rack", "~> 2.2"
 gem "redcarpet", "~> 3.5" unless ::RUBY_PLATFORM == "java"
 gem "yard", "~> 0.9.25"

lib/cloud_events/http_binding.rb

@@ -89,11 +89,11 @@ def decode_rack_env env, **format_args
       if input && content_type&.media_type == "application"
         case content_type.subtype_base
         when "cloudevents"
-          input.set_encoding content_type.charset if content_type.charset
-          return decode_structured_content input.read, content_type.subtype_format, **format_args
+          content = read_with_charset input, content_type.charset
+          return decode_structured_content content, content_type.subtype_format, **format_args
         when "cloudevents-batch"
-          input.set_encoding content_type.charset if content_type.charset
-          return decode_batched_content input.read, content_type.subtype_format, **format_args
+          content = read_with_charset input, content_type.charset
+          return decode_batched_content content, content_type.subtype_format, **format_args
         end
       end
       decode_binary_content env, content_type
@@ -152,10 +152,7 @@ def decode_binary_content env, content_type
       return nil if spec_version.nil?
       raise SpecVersionError, "Unrecognized specversion: #{spec_version}" unless spec_version == "1.0"
       input = env["rack.input"]
-      data = if input
-               input.set_encoding content_type.charset if content_type&.charset
-               input.read
-             end
+      data = read_with_charset input, content_type&.charset if input
       attributes = { "spec_version" => spec_version, "data" => data }
       attributes["data_content_type"] = content_type if content_type
       omit_names = ["specversion", "spec_version", "data", "datacontenttype", "data_content_type"]
@@ -289,6 +286,18 @@ def percent_encode str
 
     private
 
+    def read_with_charset io, charset
+      str = io.read
+      if charset
+        begin
+          str.force_encoding charset
+        rescue ::ArgumentError
+          # Do nothing for now if the charset is unrecognized
+        end
+      end
+      str
+    end
+
     def string_content_type str
       if str.encoding == ::Encoding.ASCII_8BIT
         "application/octet-stream"

test/test_http_binding.rb

@@ -6,6 +6,7 @@
 require "json"
 require "stringio"
 require "uri"
+require "rack/lint"
 
 describe CloudEvents::HttpBinding do
   let(:http_binding) { CloudEvents::HttpBinding.default }
@@ -140,6 +141,33 @@
     assert_equal my_json_struct_encoded, body
   end
 
+  it "decodes a binary rack env using an InputWrapper and re-encodes as structured" do
+    env = {
+      "rack.input"          => Rack::Lint::InputWrapper.new(StringIO.new(my_simple_data)),
+      "HTTP_CE_ID"          => my_id,
+      "HTTP_CE_SOURCE"      => my_source_string,
+      "HTTP_CE_TYPE"        => my_type,
+      "HTTP_CE_SPECVERSION" => spec_version,
+      "CONTENT_TYPE"        => my_content_type_string,
+      "HTTP_CE_DATASCHEMA"  => my_schema_string,
+      "HTTP_CE_SUBJECT"     => my_subject,
+      "HTTP_CE_TIME"        => my_time_string
+    }
+    event = http_binding.decode_rack_env env
+    assert_equal my_id, event.id
+    assert_equal my_source, event.source
+    assert_equal my_type, event.type
+    assert_equal spec_version, event.spec_version
+    assert_equal my_simple_data, event.data
+    assert_equal my_content_type, event.data_content_type
+    assert_equal my_schema, event.data_schema
+    assert_equal my_subject, event.subject
+    assert_equal my_time, event.time
+    headers, body = http_binding.encode_structured_content event, "json", sort: true
+    assert_equal({ "Content-Type" => "application/cloudevents+json" }, headers)
+    assert_equal my_json_struct_encoded, body
+  end
+
   it "decodes and re-encodes binary, honoring optional headers" do
     env = {
       "HTTP_CE_ID"          => my_id,