eslint/no-inner-declarations Pedantic
What it does
Disallow variable or function declarations in nested blocks.
Why is this bad?
A variable declaration is permitted anywhere a statement can go, even nested deeply inside other blocks. This is often undesirable due to variable hoisting, and moving declarations to the root of the program or function body can increase clarity. Note that block bindings (let, const) are not hoisted and therefore they are not affected by this rule.
Examples
Examples of incorrect code for this rule:
if (test) {
function doSomethingElse() {}
}Examples of correct code for this rule:
function doSomethingElse() {}
if (test) {
// your code here
}Configuration
The 1st option
type: "functions" | "both"
Determines what type of declarations to check.
"functions"
Disallows function declarations in nested blocks.
"both"
Disallows function and var declarations in nested blocks.
The 2nd option
This option is an object with the following properties:
blockScopedFunctions
type: "allow" | "disallow"
Controls whether function declarations in nested blocks are allowed in strict mode (ES6+ behavior).
"allow"
Allow function declarations in nested blocks in strict mode (ES6+ behavior).
"disallow"
Disallow function declarations in nested blocks regardless of strict mode.
namespaces
type: "allow" | "disallow"
Controls whether declarations directly inside TypeScript namespace or module bodies are allowed.
"allow"
Allow declarations directly inside TypeScript namespace or module bodies.
"disallow"
Disallow declarations directly inside TypeScript namespace or module bodies.
How to use
To enable this rule using the config file or in the CLI, you can use:
{
"rules": {
"no-inner-declarations": "error"
}
}import { defineConfig } from "oxlint";
export default defineConfig({
rules: {
"no-inner-declarations": "error",
},
});oxlint --deny no-inner-declarationsVersion
This rule was added in v0.0.5.