fix missing route params for CreateTestContext (gin-gonic#2778)

context_test.go

@@ -2354,3 +2354,17 @@ func TestContextAddParam(t *testing.T) {
 	assert.Equal(t, ok, true)
 	assert.Equal(t, value, v)
 }
+
+func TestCreateTestContextWithRouteParams(t *testing.T) {
+	w := httptest.NewRecorder()
+	engine := New()
+	engine.GET("/:action/:name", func(ctx *Context) {
+		ctx.String(http.StatusOK, "%s %s", ctx.Param("action"), ctx.Param("name"))
+	})
+	c := CreateTestContextOnly(w, engine)
+	c.Request, _ = http.NewRequest(http.MethodGet, "/hello/gin", nil)
+	engine.HandleContext(c)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "hello gin", w.Body.String())
+}

gin.go

@@ -201,7 +201,7 @@ func New() *Engine {
 		trustedProxies:         []string{"0.0.0.0/0", "::/0"},
 		trustedCIDRs:           defaultTrustedCIDRs,
 	}
-	engine.RouterGroup.engine = engine
+	engine.RouterGroup.engine = engine)
 	engine.pool.New = func() any {
 		return engine.allocateContext()
 	}

test_helpers.go

@@ -14,3 +14,11 @@ func CreateTestContext(w http.ResponseWriter) (c *Context, r *Engine) {
 	c.writermem.reset(w)
 	return
 }
+
+// CreateTestContextOnly returns a fresh context base on the engine for testing purposes
+func CreateTestContextOnly(w http.ResponseWriter, r *Engine) (c *Context) {
+	c = r.allocateContext()
+	c.reset()
+	c.writermem.reset(w)
+	return
+}