Rule proposal: no-restricted-loops

[zanminkian]

Description

JavaScript has 6 kind of loops. We don't really need all of them. Just allow 2 of them (by default) is enough.

Loop	Example	Allow(by default)
while	while(true){}	✅
for-of	for(const foo of bar){}	✅
for	for(let i=0;i<10;i++){}	❌
for-in	for(const foo in bar){}	❌
do-while	do{}while(foo<bar)	❌
for-await-of	for await (const num of foo()){}	❌

This rule provide an options: restricted-loops, defaults to ['for','for-in','do-while','for-await-of']

Fail

See Description.

Pass

See Description.

Proposed rule name

no-restricted-loops

Additional Info

No response

[zanminkian]

no-for-loop can be removed if this rule is implemented. no-for-loop will do auto-fixing. I don't think we need to do auto-fixing in this rule. Auto-fixing make this rule complex to understand.

[fregante]

Each loop serves a different purpose, definitely for-await-of is not something that can/should be avoided.

I think only for and for-in should generally be avoided because of their possible issues. There are already 2 rules for for:

• https://typescript-eslint.io/rules/prefer-for-of/
• https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/no-for-loop.md

I'm surprised that there's no rule or rule suggestion for for-in though. @fisker did I miss any?

[fisker]

I'm surprised that there's no rule or rule suggestion for for-in though.

There seems no rule forbids for..in loop, but only guard-for-in.

Fun fact: This is valid 😄

for (var property = 1 in object);
//                ^^^

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Deprecated_and_obsolete_features#statements