2025-04-19 23:12:19 -04:00

187 lines
4.9 KiB
JavaScript

/**
* @fileoverview A rule to set the maximum number of statements in a function.
* @author Ian Christian Myers
*/
'use strict';
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require('./utils/ast-utils');
const { upperCaseFirst } = require('../shared/string-utils');
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../types').Rule.RuleModule} */
module.exports = {
meta: {
type: 'suggestion',
docs: {
description:
'Enforce a maximum number of statements allowed in function blocks',
recommended: false,
url: 'https://eslint.org/docs/latest/rules/max-statements',
},
schema: [
{
oneOf: [
{
type: 'integer',
minimum: 0,
},
{
type: 'object',
properties: {
maximum: {
type: 'integer',
minimum: 0,
},
max: {
type: 'integer',
minimum: 0,
},
},
additionalProperties: false,
},
],
},
{
type: 'object',
properties: {
ignoreTopLevelFunctions: {
type: 'boolean',
},
},
additionalProperties: false,
},
],
messages: {
exceed:
'{{name}} has too many statements ({{count}}). Maximum allowed is {{max}}.',
},
},
create(context) {
//--------------------------------------------------------------------------
// Helpers
//--------------------------------------------------------------------------
const functionStack = [],
option = context.options[0],
ignoreTopLevelFunctions =
(context.options[1] && context.options[1].ignoreTopLevelFunctions) ||
false,
topLevelFunctions = [];
let maxStatements = 10;
if (
typeof option === 'object' &&
(Object.hasOwn(option, 'maximum') || Object.hasOwn(option, 'max'))
) {
maxStatements = option.maximum || option.max;
} else if (typeof option === 'number') {
maxStatements = option;
}
/**
* Reports a node if it has too many statements
* @param {ASTNode} node node to evaluate
* @param {int} count Number of statements in node
* @param {int} max Maximum number of statements allowed
* @returns {void}
* @private
*/
function reportIfTooManyStatements(node, count, max) {
if (count > max) {
const name = upperCaseFirst(astUtils.getFunctionNameWithKind(node));
context.report({
node,
messageId: 'exceed',
data: { name, count, max },
});
}
}
/**
* When parsing a new function, store it in our function stack
* @returns {void}
* @private
*/
function startFunction() {
functionStack.push(0);
}
/**
* Evaluate the node at the end of function
* @param {ASTNode} node node to evaluate
* @returns {void}
* @private
*/
function endFunction(node) {
const count = functionStack.pop();
/*
* This rule does not apply to class static blocks, but we have to track them so
* that statements in them do not count as statements in the enclosing function.
*/
if (node.type === 'StaticBlock') {
return;
}
if (ignoreTopLevelFunctions && functionStack.length === 0) {
topLevelFunctions.push({ node, count });
} else {
reportIfTooManyStatements(node, count, maxStatements);
}
}
/**
* Increment the count of the functions
* @param {ASTNode} node node to evaluate
* @returns {void}
* @private
*/
function countStatements(node) {
functionStack[functionStack.length - 1] += node.body.length;
}
//--------------------------------------------------------------------------
// Public API
//--------------------------------------------------------------------------
return {
FunctionDeclaration: startFunction,
FunctionExpression: startFunction,
ArrowFunctionExpression: startFunction,
StaticBlock: startFunction,
BlockStatement: countStatements,
'FunctionDeclaration:exit': endFunction,
'FunctionExpression:exit': endFunction,
'ArrowFunctionExpression:exit': endFunction,
'StaticBlock:exit': endFunction,
'Program:exit'() {
if (topLevelFunctions.length === 1) {
return;
}
topLevelFunctions.forEach((element) => {
const count = element.count;
const node = element.node;
reportIfTooManyStatements(node, count, maxStatements);
});
},
};
},
};