$on query event subscriptions for extended clients actually get applied to the underlying base client

[mziwisky]

Bug description

with an express app, I want to log every SQL query with its associated request ID (e.g. see #7596). i thought i might be able to pull this off by creating an extended client per request as suggested here, but when i attach a 'query' event listener to the extended client, it actually gets applied to the base client instead.

same thing is described here: #16500 (comment) (the comment right after that one requests that the poster open a new issue for this, but i couldn't find one, so i'm opening this one)

How to reproduce

const extended1 = prismaClient.$extends({});
extended1.$on('query', (e) => {
  console.log('query from ext1');      
});
const extended2 = prismaClient.$extends({});
extended2.$on('query', (e) => {
  console.log('query from ext2');      
});
await extended1.user.count()
// log: query from ext1
// log: query from ext2

Expected behavior

there should only be one log line, query from ext1

Prisma information

issue is independent of any particular prisma schema

Environment & setup

• OS: macOS
• Database: PostgreSQL
• Node.js version: v16.14.0

Prisma Version

prisma                  : 4.7.1
@prisma/client          : 4.7.1
Current platform        : darwin-arm64
Query Engine (Node-API) : libquery-engine 272861e07ab64f234d3ffc4094e32bd61775599c (at node_modules/@prisma/engines/libquery_engine-darwin-arm64.dylib.node)
Migration Engine        : migration-engine-cli 272861e07ab64f234d3ffc4094e32bd61775599c (at node_modules/@prisma/engines/migration-engine-darwin-arm64)
Introspection Engine    : introspection-core 272861e07ab64f234d3ffc4094e32bd61775599c (at node_modules/@prisma/engines/introspection-engine-darwin-arm64)
Format Binary           : prisma-fmt 272861e07ab64f234d3ffc4094e32bd61775599c (at node_modules/@prisma/engines/prisma-fmt-darwin-arm64)
Format Wasm             : @prisma/prisma-fmt-wasm 4.7.1-1.272861e07ab64f234d3ffc4094e32bd61775599c
Default Engines Hash    : 272861e07ab64f234d3ffc4094e32bd61775599c
Studio                  : 0.477.0