PVC Hose for Drainage?

Came across this today.
Bathroom sink had 1.25/1.5 inch reinforced PVC hose to connect the sink drain pipe to the P-trap.
The bottom of the hose is constricted down to about .5-.75" in diameter.
I ran the hot water for about 10 minutes to see if any leakage occurred and there was none.

My Spidey-senses say that this is not code.

Constructive responses please.

Thanks!

FUBAR. Size is reduced. Material is not rated for use as drain piping.

Thanks Joe,
Appreciate the knowledge and fast response!

Josh

2012 IPC: 303.1 Identification. Each length of pipe and each
pipe fi tting, trap, fi xture, material, and device utilized in a plumbing
system shall bear the identification of the manufacturer and any markings required by the applicable referenced standards.

303.4 Third-Party Testing and Certification. All plumbing products
and materials shall be listed by a third-party certification agency
as complying with the referenced standards. Products and
materials shall be identifi ed in accordance with Section*303.1.