Path parameter bug when registering different methods on similar route structures

[rtheunissen]

Issue Description

When registering these routes, we are seeing unexpected behavior:

• GET "/task/:customer/:type"
• DELETE "/task/:customer/:uuid"

The parameters of the DELETE endpoint is now customer and type, instead of customer and uuid.

Checklist

• Dependencies installed
• No typos
• Searched existing issues and docs

Expected behaviour

The parameters of the DELETE endpoint is customer and uuid.

Actual behaviour

The parameters of the DELETE endpoint is customer and type.

Steps to reproduce

Working code to debug

package main

import (
	"fmt"
	"net/http"
	"time"
	"github.com/labstack/echo/v4"
)

func main() {
	server := echo.New()
	server.HideBanner = true

	server.GET("/task/:customer/:type", func(c echo.Context) error {
		fmt.Printf("GET: %v", c.ParamNames())
		return nil
	})
	server.DELETE("/task/:customer/:uuid", func(c echo.Context) error {
		fmt.Printf("DELETE: %v", c.ParamNames())
		return nil
	})

	// Start server
	go server.Start("127.0.0.1:8080")

	// Create client and make request
	client := &http.Client{}
	req, _ := http.NewRequest("DELETE", "http://127.0.0.1:8080/task/CUSTOMER/UUID", nil)
	client.Do(req)
}

Output:

⇨ http server started on 127.0.0.1:8080
DELETE: [customer type]%  

Version/commit

v4.7.2

[amoiseiev]

In my understanding, these are the same "endpoints/paths" but different "operations". You are technically mixing two different path parameters with the same hierarchy, which is undesirable and prohibited in some specs. For instance: https://swagger.io/specification/#paths-object (OAM 3.0.3)

While different "operations" may have different "parameters", as per the same spec, path parameters cannot be different between operations as they must be derived from path. So, the tooling is not guaranteed to behave in a specific way here.

[aldas]

This is current limitation of router. This thread discusses this issue #1726 (comment)

We have reworked that limitation in v5 (no idea exactly when it will be released)

[ortyomka]

@aldas closed?

[aldas]

seems so. PR #2209 solved this "feature"