feat: implement DialURLContext(...) (#574)

Add DialURLContext so that we consumers have
control over cancelation and timeout

Convert DialURL to call DialURLContext() and update
docs to ensure consumers are aware of the new method,
which should be preferred to ensure requests can't hang
forever.

redis/conn.go

@@ -316,10 +316,17 @@ func DialContext(ctx context.Context, network, address string, options ...DialOp
 
 var pathDBRegexp = regexp.MustCompile(`/(\d*)\z`)
 
-// DialURL connects to a Redis server at the given URL using the Redis
+// DialURL wraps DialURLContext using context.Background.
+func DialURL(rawurl string, options ...DialOption) (Conn, error) {
+	ctx := context.Background()
+
+	return DialURLContext(ctx, rawurl, options...)
+}
+
+// DialURLContext connects to a Redis server at the given URL using the Redis
 // URI scheme. URLs should follow the draft IANA specification for the
 // scheme (https://www.iana.org/assignments/uri-schemes/prov/redis).
-func DialURL(rawurl string, options ...DialOption) (Conn, error) {
+func DialURLContext(ctx context.Context, rawurl string, options ...DialOption) (Conn, error) {
 	u, err := url.Parse(rawurl)
 	if err != nil {
 		return nil, err
@@ -381,7 +388,7 @@ func DialURL(rawurl string, options ...DialOption) (Conn, error) {
 
 	options = append(options, DialUseTLS(u.Scheme == "rediss"))
 
-	return Dial("tcp", address, options...)
+	return DialContext(ctx, "tcp", address, options...)
 }
 
 // NewConn returns a new Redigo connection for the given net connection.