Microsoft/TypeScript

Unable to access ServiceWorkerGlobalScope via `self.`

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#14,877 opened on Mar 27, 2017

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 (42 comments) (63 reactions) (0 assignees)TypeScript (48,455 stars) (6,726 forks)batch import
BugDomain: lib.d.tsHelp Wanted

Description

Since ServiceWorker related types sit in lib.webworker.d.ts, webworker lib need to be added to tsconfig.json.

{
  "compilerOptions": {
    "lib": [
      "es2017",
      "webworker"
    ]
  }
}

But in current lib.webworker.d.ts, it declare var self: WorkerGlobalScope;, so we can't access ServiceWorkerGlobalScope via self.

TypeScript Version: 2.2.1

Expected behavior:

Can access ServiceWorkerGlobalScope via self.(like self.clients)

Actual behavior:

Access with error.

image

Contributor guide

Tech stack
typescript
Domain
frontendtooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
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 basicsService Worker APIlib declaration files
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
The issue requests that `self` in `lib.webworker.d.ts` should be of type `ServiceWorkerGlobalScope` instead of just `WorkerGlobalScope` when the `webworker` lib is used. To fix, locate the declaration `declare var self: WorkerGlobalScope;` in `lib.webworker.d.ts` and change it to a proper conditional type or an overload that covers `ServiceWorkerGlobalScope`. Check the current version of the file to see if any changes have been made. Also review the discussion in the issue comments for any proposed approaches or objections. Note that TypeScript's lib files are auto generated, so a fix might need to be done in the upstream source.