64 lines
1.8 KiB
JavaScript
64 lines
1.8 KiB
JavaScript
/**
|
|
* @fileoverview Rule to flag use of an lexical declarations inside a case clause
|
|
* @author Erik Arvidsson
|
|
*/
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
type: "suggestion",
|
|
|
|
docs: {
|
|
description: "disallow lexical declarations in case clauses",
|
|
category: "Best Practices",
|
|
recommended: true,
|
|
url: "https://eslint.org/docs/rules/no-case-declarations"
|
|
},
|
|
|
|
schema: [],
|
|
|
|
messages: {
|
|
unexpected: "Unexpected lexical declaration in case block."
|
|
}
|
|
},
|
|
|
|
create(context) {
|
|
|
|
/**
|
|
* Checks whether or not a node is a lexical declaration.
|
|
* @param {ASTNode} node A direct child statement of a switch case.
|
|
* @returns {boolean} Whether or not the node is a lexical declaration.
|
|
*/
|
|
function isLexicalDeclaration(node) {
|
|
switch (node.type) {
|
|
case "FunctionDeclaration":
|
|
case "ClassDeclaration":
|
|
return true;
|
|
case "VariableDeclaration":
|
|
return node.kind !== "var";
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return {
|
|
SwitchCase(node) {
|
|
for (let i = 0; i < node.consequent.length; i++) {
|
|
const statement = node.consequent[i];
|
|
|
|
if (isLexicalDeclaration(statement)) {
|
|
context.report({
|
|
node: statement,
|
|
messageId: "unexpected"
|
|
});
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
}
|
|
};
|