Fix search index failure on empty "Options"

Author: qingyang-hu

.evergreen/config.yml

@@ -26,11 +26,6 @@ timeout:
       args: [ls, -la]
 
 functions:
-  assume-test-secrets-ec2-role: 
-    - command: ec2.assume_role
-      params:
-        role_arn: ${aws_test_secrets_role}
-
   setup-system:
     # Executes clone and applies the submitted patch, if any
     - command: git.get_project
@@ -439,7 +434,7 @@ functions:
       params:
         binary: "bash"
         env:
-          TEST_SEARCH_INDEX: "${MONGODB_URI}"
+          SEARCH_INDEX_URI: "${SEARCH_INDEX_URI}"
         args: [*task-runner, evg-test-search-index]
 
   add-aws-auth-variables-to-file:
@@ -2063,7 +2058,7 @@ task_groups:
         params:
           working_dir: src/go.mongodb.org/mongo-driver
           binary: bash
-          include_expansions_in_env: [AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN]
+          include_expansions_in_env: [AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN, MONGODB_URI]
           env:
             MONGODB_VERSION: ${VERSION}
             LAMBDA_STACK_NAME: dbx-go-lambda
@@ -2072,6 +2067,15 @@ task_groups:
       - command: expansions.update
         params:
           file: src/go.mongodb.org/mongo-driver/atlas-expansion.yml
+      - command: shell.exec
+        params:
+          working_dir: src/go.mongodb.org/mongo-driver
+          shell: bash
+          script: |-
+            echo "SEARCH_INDEX_URI: ${MONGODB_URI}" > atlas-expansion.yml
+      - command: expansions.update
+        params:
+          file: src/go.mongodb.org/mongo-driver/atlas-expansion.yml
     teardown_group:
       - command: subprocess.exec
         params:

Taskfile.yml

@@ -160,7 +160,7 @@ tasks:
 
   evg-test-search-index:
     # Use the long timeout to wait for the responses from the server.
-    - go test ./internal/integration -run TestSearchIndexProse -v -timeout {{.LONG_TEST_TIMEOUT}}s >> test.suite
+    - go test ./internal/integration -run TestSearchIndex -v -timeout {{.LONG_TEST_TIMEOUT}}s >> test.suite
 
   evg-test-ocsp:
     - go test -v ./mongo -run TestOCSP ${OCSP_TLS_SHOULD_SUCCEED} >> test.suite

internal/integration/search_index_prose_test.go

@@ -31,7 +31,7 @@ func TestSearchIndexProse(t *testing.T) {
 
 	const timeout = 5 * time.Minute
 
-	uri := os.Getenv("TEST_INDEX_URI")
+	uri := os.Getenv("SEARCH_INDEX_URI")
 	if uri == "" {
 		t.Skip("skipping")
 	}

internal/integration/search_index_test.go

@@ -0,0 +1,62 @@
+// Copyright (C) MongoDB, Inc. 2025-present.
+//
+// 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
+
+package integration
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+	"go.mongodb.org/mongo-driver/v2/internal/integration/mtest"
+	"go.mongodb.org/mongo-driver/v2/internal/require"
+	"go.mongodb.org/mongo-driver/v2/mongo"
+	"go.mongodb.org/mongo-driver/v2/mongo/options"
+	"go.mongodb.org/mongo-driver/v2/x/bsonx/bsoncore"
+)
+
+func TestSearchIndex(t *testing.T) {
+	t.Parallel()
+
+	const timeout = 5 * time.Minute
+
+	uri := os.Getenv("SEARCH_INDEX_URI")
+	if uri == "" {
+		t.Skip("skipping")
+	}
+
+	opts := options.Client().ApplyURI(uri).SetTimeout(timeout)
+	mt := mtest.New(t, mtest.NewOptions().ClientOptions(opts).MinServerVersion("7.0").Topologies(mtest.ReplicaSet))
+
+	mt.Run("search indexes with empty option", func(mt *mtest.T) {
+		ctx := context.Background()
+
+		expected := bson.RawArray(bsoncore.NewArrayBuilder().AppendDocument(
+			bsoncore.NewDocumentBuilder().
+				AppendDocument("definition", bsoncore.NewDocumentBuilder().
+					AppendDocument("mappings", bsoncore.NewDocumentBuilder().
+						AppendBoolean("dynamic", true).
+						Build()).
+					Build()).
+				Build()).
+			Build())
+
+		_, err := mt.Coll.SearchIndexes().CreateOne(ctx, mongo.SearchIndexModel{
+			Definition: bson.D{
+				{"mappings", bson.D{
+					{"dynamic", true},
+				}},
+			},
+		})
+		require.NoError(mt, err, "failed to create index")
+		evt := mt.GetStartedEvent()
+		actual, ok := evt.Command.Lookup("indexes").ArrayOK()
+		require.True(mt, ok, "expected command %v to contain an indexes array", evt.Command)
+		require.Equal(mt, expected, actual, "expected indexes array %v, got %v", expected, actual)
+	})
+}

mongo/search_index_view.go

@@ -123,13 +123,13 @@ func (siv SearchIndexView) CreateMany(
 		}
 
 		var iidx int32
+		iidx, indexes = bsoncore.AppendDocumentElementStart(indexes, strconv.Itoa(i))
 		if model.Options != nil {
 			searchIndexArgs, err := mongoutil.NewOptions[options.SearchIndexesOptions](model.Options)
 			if err != nil {
 				return nil, fmt.Errorf("failed to construct options from builder: %w", err)
 			}
 
-			iidx, indexes = bsoncore.AppendDocumentElementStart(indexes, strconv.Itoa(i))
 			if searchIndexArgs.Name != nil {
 				indexes = bsoncore.AppendStringElement(indexes, "name", *searchIndexArgs.Name)
 			}