Bug: `no-else-after-return` does not allow `else if`'s by default like ESLint's `no-else-return` does

Issue type

Bug

Version

v1.10.0

Overview

The no-else-after-return rule seems to, by default, be issuing warnings when else if’s are used after return statements.

The documentation for no-else-after-return states that it “Works like no-else-return from eslint”, and (at least for the current version of ESLint) the default behaviour of no-else-return allows return statements after else if’s.

Current behaviour

When no-else-after-return: true is specified, the following code causes an unnecessary else after return warning to appear for me:

const val = Math.random();

if (val > 0.5) {
  return 1;
} else if (val < 0.5) {
  return -1;
}

return 0;

Expected behaviour

When no-else-after-return: true is specified, the above code should not issue a warning.

If no-else-after-return: [true, { "allowElseIf": false }] was specified, then the above code should issue a warning.

Additional context

I use this rule as part of tslint-config-airbnb, which added no-else-after-return to their ruleset in v5.4.1.

[ajafff]

I don’t understand why you don’t want to use no-unnecessary-else, but that’s none of my business.

I actually wanted to deprecate and eventually remove no-else-after-return because it contained a lot of duplicated and slightly modified code to handle only return statements as control flow end. The rule also had quite a few bugs that never got fixed. Fortunately I have refactored my control flow analysis and can reuse it for this rule. There’s no more duplicate code and correct control flow analysis.

TL:DR

I’m going to update the rule and also add the requested option.

But there’s one thing I don’t understand: ESLint’s docs state that the following code is invalid even if allowElseIf is enabled. Why?

function foo() {
    if (x) {
        return y;
    } else if (z) {
        return w;
    } else {
        return t;
    }
}

[ajafff]

The new option is published in v1.13.0