eslint/init-declarations Style
What it does
Require or disallow initialization in variable declarations.
Why is this bad?
In JavaScript, variables can be assigned during declaration, or at any point afterwards using an assignment statement. For example, in the following code, foo is initialized during declaration, while bar is initialized later.
var foo = 1;
var bar;
if (foo) {
bar = 1;
} else {
bar = 2;
}Examples
Examples of incorrect code for the default "always" option:
/* init-declarations: ["error", "always"] */
function foo() {
var bar;
let baz;
}Examples of incorrect code for the "never" option:
/* init-declarations: ["error", "never"] */
function foo() {
var bar = 1;
let baz = 2;
for (var i = 0; i < 1; i++) {}
}Examples of correct code for the default "always" option:
/* init-declarations: ["error", "always"] */
function foo() {
var bar = 1;
let baz = 2;
const qux = 3;
}Examples of correct code for the "never" option:
/* init-declarations: ["error", "never"] */
function foo() {
var bar;
let baz;
const buzz = 1;
}Examples of correct code for the "never", { "ignoreForLoopInit": true } options:
/* init-declarations: ["error", "never", { "ignoreForLoopInit": true }] */
for (var i = 0; i < 1; i++) {}Configuration
The 1st option
type: "always" | "never"
The 2nd option
This option is an object with the following properties:
ignoreForLoopInit
type: boolean
default: false
When set to true, allows uninitialized variables in the init expression of for, for-in, and for-of loops. Only applies when mode is set to "never".
How to use
To enable this rule using the config file or in the CLI, you can use:
{
"rules": {
"init-declarations": "error"
}
}import { defineConfig } from "oxlint";
export default defineConfig({
rules: {
"init-declarations": "error",
},
});oxlint --deny init-declarationsVersion
This rule was added in v0.15.11.