Tslint: implemented interface is declared but its value is never read.

[swaheed2]

Bug Report

• __TSLint version__: 5.8.0
• __TypeScript version__: 2.5.0
• __Running TSLint via__: VSCode

Ioinic : 3.9.0

TypeScript code being linted

import { Component, Input, OnInit, OnDestroy } from '@angular/core';
export class PageBottom implements OnInit, OnDestroy {

    constructor(private appService: AppService) {
    }

    ngOnInit() {
        ...
    }
       ngOnDestroy() {
        ...
    }

}

with tslint.json configuration:

{
  "enable": true,
  "rules": {
    "no-duplicate-variable": true,
    "no-unused-variable": [
      true
    ]
  },
  "rulesDirectory": [
    "node_modules/tslint-eslint-rules/dist/rules"
  ],
  "autoFixOnSave": true
}

Actual behavior

'OnInit' is declared but its value is never read.
'OnDestroy' is declared but its value is never read.

Expected behavior

No errors

[ajafff]

Looks like a duplicate of #3463

Can you try upgrading to [email protected]? That fixed a similar issue.

[swaheed2]

Updated to 2.6.1 and still the same warnings

[ajafff]

Do you get the same errors when you enable compilerOptions.noUnusedLocals in your tsconfig.json?

[swaheed2]

yes, it looks like it's not recognizing that I have implemented OnInit.

[ajafff]

That might be a bug in TypeScript. no-unused-variable uses TypeScript's implementation of --noUnusedLocals and --noUnusedParameters behind the scenes.
If you can narrow this down to a self-contained reproduction, I suggest reporting it in the TypeScript repository.

[arush]

This is a bug for me too

TSLint version: 5.8.0
TypeScript version: 2.6.2
Running TSLint via: Node.js API

[mentatxx]

Same for me

TSLint version: 5.9.1
TypeScript version: 2.6.2
Running TSLint via: Node.js API

[JoshuaKGoldberg]

As ajafff mentioned, no-unused-variable directly reports TypeScript's diagnostics. Please file an issue on the TypeScript issue tracker if you're seeing these bugs.