From 559403b066d5eee5694cecf7714bee3a3fe36009 Mon Sep 17 00:00:00 2001
From: Gabriel Aszalos <gabriel.aszalos@gmail.com>
Date: Wed, 12 Feb 2020 10:47:32 +0200
Subject: [PATCH] contrib/gin-gonic/gin: ensure build for <v1.4.0 versions too

This change adds a hacky implementation on top of *gin.Context, ensuring
that when a version prior to v1.4.0 (with no support for
`(*gin.Context).FullPath`) is used, the code continues to build and run.
---
 contrib/gin-gonic/gin/option.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/contrib/gin-gonic/gin/option.go b/contrib/gin-gonic/gin/option.go
index 853fcf5944..67d12be4b5 100644
--- a/contrib/gin-gonic/gin/option.go
+++ b/contrib/gin-gonic/gin/option.go
@@ -7,6 +7,7 @@ package gin
 
 import (
 	"math"
+	"net/http"
 
 	"github.com/gin-gonic/gin"
 	"gopkg.in/DataDog/dd-trace-go.v1/internal/globalconfig"
@@ -59,5 +60,15 @@ func WithResourceNamer(namer func(c *gin.Context) string) Option {
 }
 
 func defaultResourceNamer(c *gin.Context) string {
-	return c.Request.Method + " " + c.FullPath()
+	// getName is a hacky way to check whether *gin.Context implements the FullPath()
+	// method introduced in v1.4.0, falling back to the previous implementation otherwise.
+	getName := func(req *http.Request, c interface{ HandlerName() string }) string {
+		if fp, ok := c.(interface {
+			FullPath() string
+		}); ok {
+			return req.Method + " " + fp.FullPath()
+		}
+		return c.HandlerName()
+	}
+	return getName(c.Request, c)
 }