2025-04-17 07:44:37 -04:00

172 lines
3.7 KiB
JavaScript

/**
* @fileoverview Rule to enforce a particular function style
* @author Nicholas C. Zakas
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../types').Rule.RuleModule} */
module.exports = {
meta: {
type: "suggestion",
defaultOptions: [
"expression",
{
allowArrowFunctions: false,
overrides: {},
},
],
docs: {
description:
"Enforce the consistent use of either `function` declarations or expressions assigned to variables",
recommended: false,
frozen: true,
url: "https://eslint.org/docs/latest/rules/func-style",
},
schema: [
{
enum: ["declaration", "expression"],
},
{
type: "object",
properties: {
allowArrowFunctions: {
type: "boolean",
},
overrides: {
type: "object",
properties: {
namedExports: {
enum: ["declaration", "expression", "ignore"],
},
},
additionalProperties: false,
},
},
additionalProperties: false,
},
],
messages: {
expression: "Expected a function expression.",
declaration: "Expected a function declaration.",
},
},
create(context) {
const [style, { allowArrowFunctions, overrides }] = context.options;
const enforceDeclarations = style === "declaration";
const { namedExports: exportFunctionStyle } = overrides;
const stack = [];
const nodesToCheck = {
FunctionDeclaration(node) {
stack.push(false);
if (
!enforceDeclarations &&
node.parent.type !== "ExportDefaultDeclaration" &&
(typeof exportFunctionStyle === "undefined" ||
node.parent.type !== "ExportNamedDeclaration")
) {
context.report({ node, messageId: "expression" });
}
if (
node.parent.type === "ExportNamedDeclaration" &&
exportFunctionStyle === "expression"
) {
context.report({ node, messageId: "expression" });
}
},
"FunctionDeclaration:exit"() {
stack.pop();
},
FunctionExpression(node) {
stack.push(false);
if (
enforceDeclarations &&
node.parent.type === "VariableDeclarator" &&
(typeof exportFunctionStyle === "undefined" ||
node.parent.parent.parent.type !==
"ExportNamedDeclaration")
) {
context.report({
node: node.parent,
messageId: "declaration",
});
}
if (
node.parent.type === "VariableDeclarator" &&
node.parent.parent.parent.type ===
"ExportNamedDeclaration" &&
exportFunctionStyle === "declaration"
) {
context.report({
node: node.parent,
messageId: "declaration",
});
}
},
"FunctionExpression:exit"() {
stack.pop();
},
"ThisExpression, Super"() {
if (stack.length > 0) {
stack[stack.length - 1] = true;
}
},
};
if (!allowArrowFunctions) {
nodesToCheck.ArrowFunctionExpression = function () {
stack.push(false);
};
nodesToCheck["ArrowFunctionExpression:exit"] = function (node) {
const hasThisOrSuperExpr = stack.pop();
if (
!hasThisOrSuperExpr &&
node.parent.type === "VariableDeclarator"
) {
if (
enforceDeclarations &&
(typeof exportFunctionStyle === "undefined" ||
node.parent.parent.parent.type !==
"ExportNamedDeclaration")
) {
context.report({
node: node.parent,
messageId: "declaration",
});
}
if (
node.parent.parent.parent.type ===
"ExportNamedDeclaration" &&
exportFunctionStyle === "declaration"
) {
context.report({
node: node.parent,
messageId: "declaration",
});
}
}
};
}
return nodesToCheck;
},
};