Tslint: no-switch-case-fall-through thrown on nested switch statements where all cases of inner switch have return statements

Created on 2 Sep 2016 · 3Comments · Source: palantir/tslint

Bug Report

TSLint version: 3.2.0
TypeScript version: 1.8.10
Running TSLint via: Node.js API

TypeScript code being linted

function foo (a: number, b: number): number {
    switch (a) {
        case 1:
            switch (b) {
                case 2:
                    return 1;
                default:
                    return 2;
            }
        default:
            return 3;
    }
}

with tslint.json configuration:

(include if relevant)

Actual behavior

Throws no-switch-case-fall-through at line before default case of the outer loop.

Expected behavior

No error.

P2 Fixed Bug

Source

sumitkmr

👍4

Most helpful comment

It does not even need to be nested to throw.

function(a: number, b:number): void {
    switch (a) {
        case 1: {
            return;
        } // Throws
        case 2:
            return;
        default:
            return;
    }
}

michaeljota on 14 Oct 2016

👍3

All 3 comments

Same for

function(a: number, b:number): void {
    switch (a) {
        case 1:
            if (b > 10) {
                return;
            } else {
                return;
            }
        case 2:
            return;
        default:
            return;
    }
}

Buuhuu on 29 Sep 2016

It does not even need to be nested to throw.

function(a: number, b:number): void {
    switch (a) {
        case 1: {
            return;
        } // Throws
        case 2:
            return;
        default:
            return;
    }
}

michaeljota on 14 Oct 2016

👍3

Same here - no-switch-case-fall-through doesn't recognize break/return inside case blocks case ... { ... }.