Automatically add prefixes to enum values if not provided

CHANGELOG

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## UNRELEASED
 
+- Automatically add prefixes to enum values if not provided
+
 # 0.1.17 - 2024-07-30
 - Ignore unknown fields in JSON decoding
 

lib/grpc_rest.rb

@@ -37,12 +37,45 @@ def assign_value(proto, path, value)
       proto.public_send(:"#{tokens.last}=", value) if proto.respond_to?(:"#{tokens.last}=")
     end
 
+    # https://stackoverflow.com/a/2158473/5199431
+    def longest_common_substring(arr)
+      return "" if arr.empty?
+
+      result = 0
+      first_val = arr[0]
+      (0...first_val.length).each do |k|
+        all_matched = true
+        character = first_val[k]
+        arr.each { |str| all_matched &= (character == str[k]) }
+        break unless all_matched
+        result += 1
+      end
+      first_val.slice(0, result)
+    end
+
+    def handle_enum_values(descriptor, value)
+      names = descriptor.subtype.to_h.keys.map(&:to_s)
+      prefix = longest_common_substring(names)
+      if prefix.present? && !value.starts_with?(prefix)
+        "#{prefix}#{value}"
+      else
+        value
+      end
+    end
+
     def map_proto_type(proto, params)
       proto.to_a.each do |descriptor|
         field = descriptor.name
         val = params[field]
         next if val.nil?
-        next if descriptor.subtype.is_a?(Google::Protobuf::EnumDescriptor)
+        if descriptor.subtype.is_a?(Google::Protobuf::EnumDescriptor)
+          if descriptor.label == :repeated
+            params[field] = val.map { |v| handle_enum_values(descriptor, v)}
+          else
+            params[field] = handle_enum_values(descriptor, val)
+          end
+          next
+        end
 
         case descriptor.type
         when *%i(int32 int64 uint32 uint64 sint32 sint64 fixed32 fixed64 sfixed32 sfixed64)

protoc-gen-rails/testdata/test_service.proto

@@ -18,6 +18,7 @@ message TestRequest {
   google.protobuf.Value bare_value = 9;
   repeated SubRecord sub_records = 10;
   int32 some_int = 11;
+  TestEnum some_enum = 12;
 }
 
 message SubRecord {
@@ -30,6 +31,12 @@ message TestResponse {
   string full_response = 2;
 }
 
+enum TestEnum {
+  TEST_ENUM_UNSPECIFIED = 0;
+  TEST_ENUM_FOO = 1;
+  TEST_ENUM_BAR = 2;
+}
+
 service MyService {
   rpc Test(TestRequest) returns (TestResponse) {
     option (google.api.http) = {

spec/grpc_rest_spec.rb

@@ -63,8 +63,8 @@ def test_4(req)
   end
 
   describe 'full body splat' do
-    it 'should be successful' do
-      params = {
+    let(:params) do
+      {
         test_id: 'abc',
         some_int: "65",
         foobar: 'xyz',
@@ -91,12 +91,26 @@ def test_4(req)
         list_value: ['F', 'Y', 'I'],
         bare_value: 45,
         timestamp_field: '2024-04-03 01:02:03 UTC',
+        some_enum: 'TEST_ENUM_FOO'
       }
+    end
+
+    it 'should be successful' do
+      post '/test4', params: params, as: :json
+      expect(response).to be_successful
+      expect(response.parsed_body).to eq({
+                                           'someInt' => 4,
+                                           'fullResponse' => %({"testId":"abc","foobar":"xyz","repeatedString":["W","T","F"],"subRecord":{"subId":"id1","anotherId":"id2"},"secondRecord":{"subId":"id3","anotherId":"id4"},"structField":{"bool_key":true,"str_key":"val","nil_key":null,"list_key":[{"inner_key":"inner_val"}],"int_key":123},"timestampField":"2024-04-03T01:02:03Z","listValue":["F","Y","I"],"bareValue":45,"someInt":65,"someEnum":"TEST_ENUM_FOO"})
+                                         })
+    end
+
+    it 'should be successful without the enum prefix' do
+      params[:some_enum] = 'FOO'
       post '/test4', params: params, as: :json
       expect(response).to be_successful
       expect(response.parsed_body).to eq({
                                            'someInt' => 4,
-                                           'fullResponse' => %({"testId":"abc","foobar":"xyz","repeatedString":["W","T","F"],"subRecord":{"subId":"id1","anotherId":"id2"},"secondRecord":{"subId":"id3","anotherId":"id4"},"structField":{"bool_key":true,"str_key":"val","nil_key":null,"list_key":[{"inner_key":"inner_val"}],"int_key":123},"timestampField":"2024-04-03T01:02:03Z","listValue":["F","Y","I"],"bareValue":45,\"someInt\":65})
+                                           'fullResponse' => %({"testId":"abc","foobar":"xyz","repeatedString":["W","T","F"],"subRecord":{"subId":"id1","anotherId":"id2"},"secondRecord":{"subId":"id3","anotherId":"id4"},"structField":{"bool_key":true,"str_key":"val","nil_key":null,"list_key":[{"inner_key":"inner_val"}],"int_key":123},"timestampField":"2024-04-03T01:02:03Z","listValue":["F","Y","I"],"bareValue":45,"someInt":65,"someEnum":"TEST_ENUM_FOO"})
                                          })
     end
   end