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/**
* @fileoverview Rule to enforce declarations in program or function body root.
* @author Brandon Mills
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
const validParent = new Set(["Program", "StaticBlock", "ExportNamedDeclaration", "ExportDefaultDeclaration"]);
const validBlockStatementParent = new Set(["FunctionDeclaration", "FunctionExpression", "ArrowFunctionExpression"]);
/**
* Finds the nearest enclosing context where this rule allows declarations and returns its description.
* @param {ASTNode} node Node to search from.
* @returns {string} Description. One of "program", "function body", "class static block body".
*/
function getAllowedBodyDescription(node) {
let { parent } = node;
while (parent) {
if (parent.type === "StaticBlock") {
return "class static block body";
}
if (astUtils.isFunction(parent)) {
return "function body";
}
({ parent } = parent);
}
return "program";
}
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "problem",
docs: {
description: "Disallow variable or `function` declarations in nested blocks",
recommended: true,
url: "https://eslint.org/docs/latest/rules/no-inner-declarations"
},
schema: [
{
enum: ["functions", "both"]
}
],
messages: {
moveDeclToRoot: "Move {{type}} declaration to {{body}} root."
}
},
create(context) {
/**
* Ensure that a given node is at a program or function body's root.
* @param {ASTNode} node Declaration node to check.
* @returns {void}
*/
function check(node) {
const parent = node.parent;
if (
parent.type === "BlockStatement" && validBlockStatementParent.has(parent.parent.type)
) {
return;
}
if (validParent.has(parent.type)) {
return;
}
context.report({
node,
messageId: "moveDeclToRoot",
data: {
type: (node.type === "FunctionDeclaration" ? "function" : "variable"),
body: getAllowedBodyDescription(node)
}
});
}
return {
FunctionDeclaration: check,
VariableDeclaration(node) {
if (context.options[0] === "both" && node.kind === "var") {
check(node);
}
}
};
}
};