ngx-safe-subscribe-cli

A command-line tool that scans an Angular / RxJS codebase for unmanaged subscriptions — the .subscribe() calls that are never torn down and leak memory. It reports the file, line number, and a total count, and exits with code 1 when leaks are found so you can wire it into CI.

Install

npm install --save-dev ngx-safe-subscribe-cli

Or run it once without installing:

npx ngx-safe-subscribe-cli scan ./src

Usage

ngx-safe-subscribe scan <path> [--json]

Examples:

ngx-safe-subscribe scan ./src
ngx-safe-subscribe scan "src/**/*.ts"
ngx-safe-subscribe scan ./src --json

Example output

🔍  Scanned 42 file(s) in "./src"

⚠️   2 potentially unmanaged subscription(s):

  src/app/home/home.component.ts:24:5
     interval(1000).subscribe((x) => console.log(x))

  src/app/list/list.component.ts:41:9
     this.dataService.getUsers().subscribe((u) => (this.users = u))

Summary: 2 risky / 13 safe / 15 total subscriptions.

Use it in CI

Because it exits with code 1 when leaks are found, you can block merges that introduce new leaks:

# package.json
"scripts": {
  "lint:leaks": "ngx-safe-subscribe scan ./src"
}

What counts as "safe"

A subscription is considered safe when:

• The chain uses a completing operator — takeUntil, takeUntilDestroyed, untilDestroyed, take, first, takeWhile.
• It's added to a composite subscription — this.sub.add(source.subscribe()).
• Its handle is .unsubscribe()d somewhere in the same file.
• It's stored on this in a class decorated with @AutoUnsubscribe() (the decorator tears it down automatically).

Everything else is flagged. This is a heuristic (it doesn't run your app), so review findings before acting on them.

License

MIT