feat: set custom request body schemas

operation.go

@@ -135,6 +135,12 @@ func (o *Operation) NoBodyReadTimeout() {
 	o.bodyReadTimeout = 0
 }
 
+// RequestSchema allows overriding the generated input body schema, giving you
+// more control over documentation and validation.
+func (o *Operation) RequestSchema(s *schema.Schema) {
+	o.requestSchema = s
+}
+
 // Run registers the handler function for this operation. It should be of the
 // form: `func (ctx huma.Context)` or `func (ctx huma.Context, input)` where
 // input is your input struct describing the input parameters and/or body.
@@ -182,9 +188,12 @@ func (o *Operation) Run(handler interface{}) {
 		// Get body if present.
 		if body, ok := input.FieldByName("Body"); ok {
 			o.requestModel = body.Type
-			o.requestSchema, err = schema.GenerateWithMode(body.Type, schema.ModeWrite, nil)
-			if err != nil {
-				panic(fmt.Errorf("unable to generate JSON schema: %w", err))
+
+			if o.requestSchema == nil {
+				o.requestSchema, err = schema.GenerateWithMode(body.Type, schema.ModeWrite, nil)
+				if err != nil {
+					panic(fmt.Errorf("unable to generate JSON schema: %w", err))
+				}
 			}
 		}
 

router_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/istreamlabs/huma/schema"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -338,3 +339,26 @@ func TestRouterAutoConfig(t *testing.T) {
 		},
 	})
 }
+
+func TestCustomRequestSchema(t *testing.T) {
+	app := newTestRouter()
+
+	op := app.Resource("/foo").Post("id", "doc", NewResponse(http.StatusOK, "ok"))
+	op.RequestSchema(&schema.Schema{
+		Type:    schema.TypeInteger,
+		Minimum: schema.F(0),
+		Maximum: schema.F(100),
+	})
+	op.Run(func(ctx Context, input struct {
+		Body int
+	}) {
+		// Custom schema should be used so we never get here.
+		ctx.WriteHeader(http.StatusOK)
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodPost, "/foo", strings.NewReader("1234"))
+	app.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusBadRequest, w.Result().StatusCode)
+}