add fuzz driver based on TestUseRouterParentDisallow (#2217)

core/router/TestUseRouterParentDisallow_fuzz_test.go

@@ -0,0 +1,55 @@
+package router_test
+
+import (
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/httptest"
+	"testing"
+)
+
+func FuzzTestUseRouterParentDisallow(f *testing.F) {
+	f.Add("no_userouter_allowed", "always", "_2", "_3", "/index", "/", "/user")
+	f.Fuzz(func(t *testing.T, data1 string, data2 string, data3 string, data4 string, data5 string,
+		data6 string, data7 string) {
+		app := iris.New()
+		app.UseRouter(func(ctx iris.Context) {
+			ctx.WriteString(data2)
+			ctx.Next()
+		})
+		app.Get(data5, func(ctx iris.Context) {
+			ctx.WriteString(data1)
+		})
+
+		app.SetPartyMatcher(func(ctx iris.Context, p iris.Party) bool {
+			// modifies the PartyMatcher to not match any UseRouter,
+			// tests should receive the handlers response alone.
+			return false
+		})
+
+		app.PartyFunc(data6, func(p iris.Party) { // it's the same instance of app.
+			p.UseRouter(func(ctx iris.Context) {
+				ctx.WriteString(data3)
+				ctx.Next()
+			})
+			p.Get(data6, func(ctx iris.Context) {
+				ctx.WriteString(data1)
+			})
+		})
+
+		app.PartyFunc(data7, func(p iris.Party) {
+			p.UseRouter(func(ctx iris.Context) {
+				ctx.WriteString(data4)
+				ctx.Next()
+			})
+
+			p.Get(data6, func(ctx iris.Context) {
+				ctx.WriteString(data1)
+			})
+		})
+
+		e := httptest.New(t, app)
+		e.GET(data5)
+		e.GET(data6)
+		e.GET(data7)
+
+	})
+}