Bad error when using import() type within JSDoc tag @implements

[jaydenseric]

🔎 Search Terms

• import
• @implements
• 2304

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about the JSDoc tag @implements

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.5.0-beta&filetype=js#code/PQKhAIAEEsFsAcA2BTWyB2AXAzuA3nPAPYBOmAFAEQCGlAlAHQBCAvuCMAFADGi12uAIL4WQA

💻 Code

/** @implements {import("a").B} */
class A {}

🙁 Actual behavior

Two TypeScript errors:

1. Cannot find name 'import'. (2304)
2. '}' expected. (2304)

🙂 Expected behavior

TypeScript should allow using import() types within the type of the JSDoc tag @implements.

Additional information about the issue

A workaround is to use a JSDoc @typedef to import the type under an alias, and then use that alias within the JSDoc tag @implements type, e.g:

/** @typedef {import("a").B} B */

/** @implements {B} */
class A {}

[sandersn]

@implements uses the same grammar as Typescript implements. This is an error in Typescript:

class A implements import("a").B {}

However, the error is informative in typescript: "A class can only implement an identifier..." and not in Javascript. Javascript should give the same error.

With the new @import tag, you should be able to /** @import { B } from 'a' */ instead of using @typedef.

[jaydenseric]

See also #49905 .