refactor(gateway): make LandController operate on entities

service/submitqueue/gateway/server/BUILD.bazel

@@ -19,6 +19,7 @@ go_library(
         "//platform/extension/counter/mysql:go_default_library",
         "//platform/extension/messagequeue:go_default_library",
         "//platform/extension/messagequeue/mysql:go_default_library",
+        "//service/submitqueue/gateway/server/mapper:go_default_library",
         "//submitqueue/core/topickey:go_default_library",
         "//submitqueue/extension/queueconfig/yaml:go_default_library",
         "//submitqueue/extension/storage/mysql:go_default_library",

service/submitqueue/gateway/server/main.go

@@ -36,6 +36,7 @@ import (
 	mysqlcounter "github.com/uber/submitqueue/platform/extension/counter/mysql"
 	extqueue "github.com/uber/submitqueue/platform/extension/messagequeue"
 	queueMySQL "github.com/uber/submitqueue/platform/extension/messagequeue/mysql"
+	"github.com/uber/submitqueue/service/submitqueue/gateway/server/mapper"
 	"github.com/uber/submitqueue/submitqueue/core/topickey"
 	yamlqueueconfig "github.com/uber/submitqueue/submitqueue/extension/queueconfig/yaml"
 	mysqlstorage "github.com/uber/submitqueue/submitqueue/extension/storage/mysql"
@@ -62,9 +63,18 @@ func (s *GatewayServer) Ping(ctx context.Context, req *pb.PingRequest) (*pb.Ping
 	return s.pingController.Ping(ctx, req)
 }
 
-// Land delegates to the controller
+// Land maps the wire request to an entity, delegates to the controller, and maps
+// the result back to the wire response.
 func (s *GatewayServer) Land(ctx context.Context, req *pb.LandRequest) (*pb.LandResponse, error) {
-	return s.landController.Land(ctx, req)
+	landReq, err := mapper.ProtoToLandRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	result, err := s.landController.Land(ctx, landReq)
+	if err != nil {
+		return nil, err
+	}
+	return &pb.LandResponse{Sqid: result.ID}, nil
 }
 
 // Cancel delegates to the controller

service/submitqueue/gateway/server/mapper/BUILD.bazel

@@ -0,0 +1,31 @@
+load("@rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["land.go"],
+    importpath = "github.com/uber/submitqueue/service/submitqueue/gateway/server/mapper",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//api/base/mergestrategy/protopb:go_default_library",
+        "//api/submitqueue/gateway/protopb:go_default_library",
+        "//platform/base/change:go_default_library",
+        "//platform/base/mergestrategy:go_default_library",
+        "//submitqueue/entity:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["land_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//api/base/change/protopb:go_default_library",
+        "//api/base/mergestrategy/protopb:go_default_library",
+        "//api/submitqueue/gateway/protopb:go_default_library",
+        "//platform/base/change:go_default_library",
+        "//platform/base/mergestrategy:go_default_library",
+        "//submitqueue/entity:go_default_library",
+        "@com_github_stretchr_testify//assert:go_default_library",
+        "@com_github_stretchr_testify//require:go_default_library",
+    ],
+)

service/submitqueue/gateway/server/mapper/land.go

@@ -0,0 +1,65 @@
+// Copyright (c) 2025 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package mapper translates gateway wire (proto) types to and from the domain
+// entities the controllers operate on. Each RPC gets its own file (land.go,
+// status.go, cancel.go, …); translation lives here so controllers stay
+// proto-free.
+package mapper
+
+import (
+	"errors"
+	"fmt"
+
+	mergestrategypb "github.com/uber/submitqueue/api/base/mergestrategy/protopb"
+	pb "github.com/uber/submitqueue/api/submitqueue/gateway/protopb"
+	"github.com/uber/submitqueue/platform/base/change"
+	"github.com/uber/submitqueue/platform/base/mergestrategy"
+	"github.com/uber/submitqueue/submitqueue/entity"
+)
+
+// errUnknownStrategy is returned when a proto Strategy enum has no known
+// mergestrategy.MergeStrategy mapping.
+var errUnknownStrategy = errors.New("unknown land strategy in proto message")
+
+// ProtoToLandRequest maps the wire LandRequest to the entity.LandRequest the controller operates on.
+// The ID is left empty; the controller assigns it.
+func ProtoToLandRequest(req *pb.LandRequest) (entity.LandRequest, error) {
+	strategy, err := resolveMergeStrategy(req.GetStrategy())
+	if err != nil {
+		return entity.LandRequest{}, fmt.Errorf("failed to map land strategy: %w", err)
+	}
+	return entity.LandRequest{
+		Queue:        req.GetQueue(),
+		Change:       change.Change{URIs: req.GetChange().GetUris()},
+		LandStrategy: strategy,
+	}, nil
+}
+
+// resolveMergeStrategy maps a proto Strategy enum to the shared mergestrategy.MergeStrategy.
+func resolveMergeStrategy(s mergestrategypb.Strategy) (mergestrategy.MergeStrategy, error) {
+	switch s {
+	case mergestrategypb.Strategy_DEFAULT:
+		// TODO: resolve default strategy based on queue configuration
+		return mergestrategy.MergeStrategyRebase, nil
+	case mergestrategypb.Strategy_REBASE:
+		return mergestrategy.MergeStrategyRebase, nil
+	case mergestrategypb.Strategy_SQUASH_REBASE:
+		return mergestrategy.MergeStrategySquashRebase, nil
+	case mergestrategypb.Strategy_MERGE:
+		return mergestrategy.MergeStrategyMerge, nil
+	default:
+		return mergestrategy.MergeStrategyUnknown, fmt.Errorf("%w: %v", errUnknownStrategy, s)
+	}
+}

service/submitqueue/gateway/server/mapper/land_test.go

@@ -0,0 +1,111 @@
+// Copyright (c) 2025 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mapper
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	changepb "github.com/uber/submitqueue/api/base/change/protopb"
+	mergestrategypb "github.com/uber/submitqueue/api/base/mergestrategy/protopb"
+	pb "github.com/uber/submitqueue/api/submitqueue/gateway/protopb"
+	"github.com/uber/submitqueue/platform/base/change"
+	"github.com/uber/submitqueue/platform/base/mergestrategy"
+	"github.com/uber/submitqueue/submitqueue/entity"
+)
+
+func TestProtoToLandRequest(t *testing.T) {
+	const uri = "github://github.example.com/uber/test-repo/pull/1/c3a4d5e6f7890123456789abcdef0123456789ab"
+
+	tests := []struct {
+		name        string
+		req         *pb.LandRequest
+		expected    entity.LandRequest
+		expectedErr error
+	}{
+		{
+			name: "maps all fields and leaves ID empty",
+			req: &pb.LandRequest{
+				Queue:    "test-queue",
+				Change:   &changepb.Change{Uris: []string{uri}},
+				Strategy: mergestrategypb.Strategy_SQUASH_REBASE,
+			},
+			// ID is not assigned by the mapper — the controller mints it.
+			expected: entity.LandRequest{
+				Queue:        "test-queue",
+				Change:       change.Change{URIs: []string{uri}},
+				LandStrategy: mergestrategy.MergeStrategySquashRebase,
+			},
+		},
+		{
+			name: "nil change yields empty URIs without erroring",
+			req:  &pb.LandRequest{Queue: "test-queue", Change: nil},
+			// The mapper does not validate; it leaves URIs empty for the controller to reject.
+			expected: entity.LandRequest{
+				Queue:        "test-queue",
+				LandStrategy: mergestrategy.MergeStrategyRebase,
+			},
+		},
+		{
+			name: "unknown strategy errors",
+			req: &pb.LandRequest{
+				Queue:    "test-queue",
+				Change:   &changepb.Change{Uris: []string{uri}},
+				Strategy: mergestrategypb.Strategy(9999),
+			},
+			expectedErr: errUnknownStrategy,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := ProtoToLandRequest(tt.req)
+			if tt.expectedErr != nil {
+				require.ErrorIs(t, err, tt.expectedErr)
+				return
+			}
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}
+
+func TestResolveMergeStrategy(t *testing.T) {
+	tests := []struct {
+		name   string
+		in     mergestrategypb.Strategy
+		want   mergestrategy.MergeStrategy
+		errMsg string
+	}{
+		{name: "default", in: mergestrategypb.Strategy_DEFAULT, want: mergestrategy.MergeStrategyRebase},
+		{name: "rebase", in: mergestrategypb.Strategy_REBASE, want: mergestrategy.MergeStrategyRebase},
+		{name: "squash_rebase", in: mergestrategypb.Strategy_SQUASH_REBASE, want: mergestrategy.MergeStrategySquashRebase},
+		{name: "merge", in: mergestrategypb.Strategy_MERGE, want: mergestrategy.MergeStrategyMerge},
+		{name: "unknown", in: mergestrategypb.Strategy(9999), errMsg: "unknown land strategy in proto message"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := resolveMergeStrategy(tt.in)
+			if tt.errMsg != "" {
+				assert.ErrorContains(t, err, tt.errMsg)
+				return
+			}
+			assert.NoError(t, err)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}

submitqueue/entity/BUILD.bazel

@@ -11,7 +11,7 @@ go_library(
         "change_provider.go",
         "change_record.go",
         "conflict.go",
-        "land_request.go",
+        "land.go",
         "merge_result.go",
         "push_result.go",
         "queue.go",
@@ -36,7 +36,7 @@ go_test(
         "batch_test.go",
         "build_test.go",
         "cancel_request_test.go",
-        "land_request_test.go",
+        "land_test.go",
         "queue_test.go",
         "request_log_test.go",
         "request_test.go",

submitqueue/entity/land_request.go → submitqueue/entity/land.go

@@ -46,3 +46,12 @@ func LandRequestFromBytes(data []byte) (LandRequest, error) {
 	err := json.Unmarshal(data, &req)
 	return req, err
 }
+
+// LandResult is the outcome of accepting a land request. It carries the ID the
+// controller assigned to the request so the transport layer can echo it back to
+// the caller.
+type LandResult struct {
+	// ID is the globally unique identifier assigned to the accepted land request.
+	// Format: "<queue>/<counter_value>".
+	ID string
+}

submitqueue/gateway/controller/BUILD.bazel

@@ -11,10 +11,7 @@ go_library(
     importpath = "github.com/uber/submitqueue/submitqueue/gateway/controller",
     visibility = ["//visibility:public"],
     deps = [
-        "//api/base/mergestrategy/protopb:go_default_library",
         "//api/submitqueue/gateway/protopb:go_default_library",
-        "//platform/base/change:go_default_library",
-        "//platform/base/mergestrategy:go_default_library",
         "//platform/base/messagequeue:go_default_library",
         "//platform/consumer:go_default_library",
         "//platform/errs:go_default_library",
@@ -40,9 +37,8 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
-        "//api/base/change/protopb:go_default_library",
-        "//api/base/mergestrategy/protopb:go_default_library",
         "//api/submitqueue/gateway/protopb:go_default_library",
+        "//platform/base/change:go_default_library",
         "//platform/base/mergestrategy:go_default_library",
         "//platform/base/messagequeue:go_default_library",
         "//platform/consumer:go_default_library",