Description

import * as vscode from 'vscode';

function LogMethod(
  target: any,
  propertyKey: string | symbol,
  descriptor: PropertyDescriptor
) {
  console.log(target);
  console.log(propertyKey);
  console.log(descriptor);
}

class Demo {
  @LogMethod
  public foo(bar: vscode.Memento) {
    // do nothing
  }
}

const demo = new Demo();

Contributor guide

Tech stack

typescript

Domain

tooling

Issue type

bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

4

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

1-2 days

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

TypeScript compiler internalsdecoratorsemitDecoratorMetadata

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

20

Research direction

Investigate the TypeScript compiler's code emission logic in src/compiler/emitter.ts, specifically the handling of decorator metadata (emitDecoratorMetadata). The issue is that when emitDecoratorMetadata is true, the compiler fails to elide imports that are only used as types in decorator metadata. Review the import elision algorithm and the generateMetadataCalls function to understand why the import is retained. Look for any existing tests related to import elision with decorators.