JSDoc template interference

[dyst5422]

TypeScript Version: 2.4

Code
Example 0
ERROR: error TS2536: Type '"prop"' cannot be used to index type 'T'.
ERROR: error TS2339: Property 'prop' does not exist on type 'T'.

/**
 * Example 0
 * @class GenericClass
 * @template T
 */
class GenericClass<T extends { prop: string }> { // Doesn't work
  public insert(arg: T): T['prop'] {
    return arg.prop;
  }
}

Example 1
Works fine

/**
 * Example 1
 * @class OtherGenericClass
 */
class OtherGenericClass<T extends { prop: string }> { // Works
  public insert(arg: T): T['prop'] {
    return arg.prop;
  }
}

Example 2
ERROR: error TS2536: Type '"prop"' cannot be used to index type 'T'.
ERROR: error TS2339: Property 'prop' does not exist on type 'T'.

/**
 * Example 2
 * @template T
 * @param {T} arg
 * @returns {T['prop']}
 */
function myFunc<T extends { prop: string }> (arg: T): T['prop'] { // Doesn't work
  return arg.prop;
}

Example 3
Works fine

/**
 * Example 3
 * @param {R} arg
 * @returns {R['prop']}
 */
function myOtherFunc<R extends { prop: string }> (arg: R): R['prop'] { // Works
  return arg.prop;
}

Expected behavior:
Template declaration in JSDoc comments should not supersede the in-code template declarations.

Actual behavior:
In example 0 and 2 above, the generic type T is not found to properly extend { prop: string } when the JSDoc comment exists presumably because the JSDoc comment supersedes the type defined inline. This should never be the case where a non-code element takes precedence over the code contents.

[dyst5422]

#16411 is related

[ghost]

Duplicate of #16358. Fixed in typescript@next.

[dyst5422]

Ah good. I looked around for a bit, but hadn't seen that one. I'll close this duplicate issue.