eslint/curly Style
What it does
This rule enforces the use of curly braces {} for all control statements (if, else, for, while, do, with). It ensures that all blocks are enclosed in curly braces to improve code clarity and maintainability.
Why is this bad?
Omitting curly braces can reduce code readability and increase the likelihood of errors, especially in deeply nested or indented code. It can also lead to bugs if additional statements are added later without properly enclosing them in braces. Using curly braces consistently makes the code safer and easier to modify.
Examples
"all" (default)
Examples of incorrect code for this rule:
js
/* curly: ["error", "all"] */
if (foo) foo++;
while (bar) bar--;
do foo(); while (bar);Examples of correct code for this rule:
js
/* curly: ["error", "all"] */
if (foo) foo++;
while (bar) bar--;
do {
foo();
} while (bar);"multi"
Examples of incorrect code for this rule with the "multi" option:
js
/* curly: ["error", "multi"] */
if (foo) foo();
else {
bar();
baz();
}Examples of correct code for this rule with the "multi" option:
js
/* curly: ["error", "multi"] */
if (foo) foo();
else bar();"multi-line"
Examples of incorrect code for this rule with the "multi-line" option:
js
/* curly: ["error", "multi-line"] */
if (foo) foo();
else {
bar();
}
while (foo) {
foo();
}Examples of correct code for this rule with the "multi-line" option:
js
/* curly: ["error", "multi-line"] */
if (foo) foo();
else bar();
while (foo) foo();
while (true) {
doSomething();
doSomethingElse();
}"multi-or-nest"
Examples of incorrect code for this rule with the "multi-or-nest" option:
js
/* curly: ["error", "multi-or-nest"] */
if (foo) {
if (bar) bar();
}
while (foo) {
while (bar) bar();
}Examples of correct code for this rule with the "multi-or-nest" option:
js
/* curly: ["error", "multi-or-nest"] */
if (foo) {
if (bar) bar();
}
while (foo) {
while (bar) bar();
}{ "consistent": true }
When enabled, consistent: true enforces consistent use of braces within an if-else chain. If one branch of the chain uses braces, then all branches must use braces, even if not strictly required by the first option.
Examples of incorrect code with "multi" and consistent: true:
js
/* curly: ["error", "multi", "consistent"] */
if (foo) {
bar();
baz();
} else qux();
if (foo) bar();
else {
baz();
qux();
}Examples of correct code with "multi" and consistent: true:
js
/* curly: ["error", "multi", "consistent"] */
if (foo) {
bar();
baz();
} else {
qux();
}
if (foo) {
bar();
} else {
baz();
qux();
}Examples of incorrect code with "multi-line" and consistent: true:
js
/* curly: ["error", "multi-line", "consistent"] */
if (foo) {
bar();
} else {
baz();
}Examples of correct code with "multi-line" and consistent: true:
js
/* curly: ["error", "multi-line", "consistent"] */
if (foo) {
bar();
} else {
baz();
}Examples of incorrect code with "multi-or-nest" and consistent: true:
js
/* curly: ["error", "multi-or-nest", "consistent"] */
if (foo) {
if (bar) baz();
} else qux();Examples of correct code with "multi-or-nest" and consistent: true:
js
/* curly: ["error", "multi-or-nest", "consistent"] */
if (foo) {
if (bar) baz();
} else {
qux();
}Configuration
This rule accepts a configuration object with the following properties:
consistent
type: boolean
default: false
Whether to enforce consistent use of curly braces in if-else chains.
curlyType
type: "all" | "multi" | "multi-line" | "multi-or-nest"
default: "all"
Which type of curly brace enforcement to use.
"all": require braces in all cases"multi": require braces only for multi-statement blocks"multi-line": require braces only for multi-line blocks"multi-or-nest": require braces for multi-line blocks or when nested
How to use
To enable this rule in the CLI or using the config file, you can use:
bash
oxlint --deny curlyjson
{
"rules": {
"curly": "error"
}
}