Support Forcing Unique Operation IDs (Fixes #910)

group_test.go

@@ -96,7 +96,7 @@ func TestGroupConvenienceEquivalency(t *testing.T) {
 	// Ensure group overrides still work.
 	grp4 := huma.NewGroup(api, "/v4")
 	grp4.UseModifier(func(op *huma.Operation, next func(*huma.Operation)) {
-		op.OperationID = "custom-id"
+		op.OperationID = "custom-id-2"
 		op.Summary = "Custom summary"
 		next(op)
 	})
@@ -123,7 +123,7 @@ func TestGroupConvenienceEquivalency(t *testing.T) {
 	assert.Equal(t, "get-v1-users", oapi.Paths["/v1/users"].Get.OperationID)
 	assert.Equal(t, "get-v2-users", oapi.Paths["/v2/users"].Get.OperationID)
 	assert.Equal(t, "custom-id", oapi.Paths["/v3/users"].Get.OperationID)
-	assert.Equal(t, "custom-id", oapi.Paths["/v4/users"].Get.OperationID)
+	assert.Equal(t, "custom-id-2", oapi.Paths["/v4/users"].Get.OperationID)
 	assert.Equal(t, "get-v5-users", oapi.Paths["/v5/users/"].Get.OperationID)
 
 	assert.Equal(t, "Get v1 users", oapi.Paths["/v1/users"].Get.Summary)

openapi.go

@@ -1495,9 +1495,23 @@ type OpenAPI struct {
 
 // AddOperation adds an operation to the OpenAPI. This is the preferred way to
 // add operations to the OpenAPI, as it will ensure that the operation is
-// properly added to the Paths map, and will call any registered OnAddOperation
+// properly added to the Paths map and will call any registered OnAddOperation
 // functions.
 func (o *OpenAPI) AddOperation(op *Operation) {
+	// Check this won't create a duplicate operation ID.
+	if op.OperationID != "" {
+		for _, pathItem := range o.Paths {
+			for _, existingOp := range []*Operation{
+				pathItem.Get, pathItem.Post, pathItem.Put, pathItem.Patch,
+				pathItem.Delete, pathItem.Head, pathItem.Options, pathItem.Trace,
+			} {
+				if existingOp != nil && existingOp.OperationID == op.OperationID {
+					panic("duplicate operation ID: " + op.OperationID)
+				}
+			}
+		}
+	}
+
 	if o.Paths == nil {
 		o.Paths = map[string]*PathItem{}
 	}

openapi_test.go

@@ -1,6 +1,7 @@
 package huma_test
 
 import (
+	"net/http"
 	"testing"
 
 	"github.com/danielgtaylor/huma/v2"
@@ -265,3 +266,20 @@ func TestDowngrade(t *testing.T) {
 	// Check that the downgrade worked as expected.
 	assert.JSONEq(t, expected, string(v30))
 }
+
+func TestAddOperationForceUniqueOperationIDs(t *testing.T) {
+	oapi := &huma.OpenAPI{}
+	oapi.AddOperation(&huma.Operation{
+		OperationID: "test",
+		Method:      http.MethodGet,
+		Path:        "/test",
+	})
+
+	assert.PanicsWithValue(t, "duplicate operation ID: test", func() {
+		oapi.AddOperation(&huma.Operation{
+			OperationID: "test",
+			Method:      http.MethodPost,
+			Path:        "/test",
+		})
+	})
+}