Fix sub default propagate params

context.go

@@ -62,8 +62,6 @@ type RequestContext interface {
 	QueryParam(name string) string
 	// Header retrieves the value of the request header for the given key.
 	Header(key string) string
-	// Pattern returns the registered route pattern or an empty string if the handler is called in a scope other than [RouteHandler].
-	Pattern() string
 }
 
 // Context represents the context of the current HTTP request. It provides methods to access request data and

fox.go

@@ -1003,6 +1003,8 @@ func Sub(router *Router) HandlerFunc {
 			// gracefully as a defensive measure: if the parent registers /api and the sub-router registers /,
 			// we treat it similarly to /api*{any} (optional wildcard), matching /api with the pattern /api/.
 			*subCtx.subPatterns = append(*subCtx.subPatterns, strings.TrimSuffix(c.pattern, "/"))
+			*subCtx.params = append(*subCtx.params, *c.params...)
+			*subCtx.paramsKeys = append((*subCtx.paramsKeys)[:0], keys...)
 			router.serveSubRouter(subCtx, "/")
 			return
 		}

fox_test.go

@@ -1434,6 +1434,26 @@ func TestRouter_ServeHTTP_HandleSubRouter(t *testing.T) {
 		assert.Equal(t, http.StatusNotFound, w.Code)
 	})
 
+	t.Run("sub-router with parent param and static suffix propagates params", func(t *testing.T) {
+		var paramSeen, patternSeen string
+		sub := MustRouter()
+		sub.MustAdd(MethodGet, "/", func(c *Context) {
+			paramSeen = c.Param("ver")
+			patternSeen = c.Pattern()
+		})
+
+		fx := MustRouter()
+		require.NoError(t, onlyError(fx.Add(MethodGet, "/api/{ver}/admin", Sub(sub))))
+
+		req := httptest.NewRequest(http.MethodGet, "/api/v1/admin", nil)
+		w := httptest.NewRecorder()
+		fx.ServeHTTP(w, req)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+		assert.Equal(t, "v1", paramSeen)
+		assert.Equal(t, "/api/{ver}/admin/", patternSeen)
+	})
+
 	t.Run("sub-router registered in non route handler", func(t *testing.T) {
 		sub := MustRouter()
 		sub.MustAdd(MethodGet, "/users", patternHandler)

tree.go

@@ -47,15 +47,11 @@ func (t *iTree) lookupByPath(method, path string, c *Context, lazy bool) (int, *
 }
 
 func (t *iTree) allocateContext() *Context {
-	patterns := make([]string, 0)
-	params := make([]string, 0, t.maxParams)
-	keys := make([]string, 0, t.maxParams)
-	stacks := make(skipStack, 0, t.maxDepth)
 	return &Context{
-		params:      &params,
-		skipStack:   &stacks,
-		paramsKeys:  &keys,
-		subPatterns: &patterns,
+		params:      new(make([]string, 0, t.maxParams)),
+		skipStack:   new(make(skipStack, 0, t.maxDepth)),
+		paramsKeys:  new(make([]string, 0, t.maxParams)),
+		subPatterns: new(make([]string, 0)),
 		// This is a read only value, no reset. It's always the
 		// owner of the pool.
 		tree: t,