eslint-plugin-sonarjs
Version:
SonarJS rules for ESLint
171 lines (170 loc) • 6.67 kB
JavaScript
;
/*
* SonarQube JavaScript Plugin
* Copyright (C) 2011-2025 SonarSource SA
* mailto:info AT sonarsource DOT com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the Sonar Source-Available License Version 1, as published by SonarSource SA.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the Sonar Source-Available License for more details.
*
* You should have received a copy of the Sonar Source-Available License
* along with this program; if not, see https://sonarsource.com/license/ssal/
*/
// Greatly inspired by https://github.com/eslint/eslint/blob/561b6d4726f3e77dd40ba0d340ca7f08429cd2eb/lib/rules/max-lines-per-function.js
// We had to fork the implementation to control the reporting (issue location), in order to provide a better user experience.
Object.defineProperty(exports, "__esModule", { value: true });
exports.rule = void 0;
exports.getLocsNumber = getLocsNumber;
exports.getCommentLineNumbers = getCommentLineNumbers;
const index_js_1 = require("../helpers/index.js");
const meta_js_1 = require("./meta.js");
const DEFAULT = 200;
const messages = {
functionMaxLine: 'This function has {{lineCount}} lines, which is greater than the {{threshold}} lines authorized. Split it into smaller functions.',
};
exports.rule = {
meta: (0, index_js_1.generateMeta)(meta_js_1.meta, { messages, schema: meta_js_1.schema }),
create(context) {
const threshold = context.options[0]?.maximum ?? DEFAULT;
const sourceCode = context.sourceCode;
const lines = sourceCode.lines;
const commentLineNumbers = getCommentLineNumbers(sourceCode.getAllComments());
const functionStack = [];
const functionKnowledge = new Map();
return {
'FunctionDeclaration, FunctionExpression, ArrowFunctionExpression': (node) => {
functionStack.push(node);
const parent = (0, index_js_1.getParent)(context, node);
if (!node.loc || isIIFE(node, parent)) {
return;
}
const lineCount = getLocsNumber(node.loc, lines, commentLineNumbers);
const startsWithCapital = nameStartsWithCapital(node);
functionKnowledge.set(node, { node, lineCount, startsWithCapital, returnsJSX: false });
},
ReturnStatement: (node) => {
const returnStatement = node;
const knowledge = functionKnowledge.get((0, index_js_1.last)(functionStack));
if (knowledge &&
returnStatement.argument &&
returnStatement.argument.type.startsWith('JSX')) {
knowledge.returnsJSX = true;
}
},
'FunctionDeclaration:exit': () => {
functionStack.pop();
},
'FunctionExpression:exit': () => {
functionStack.pop();
},
'ArrowFunctionExpression:exit': () => {
functionStack.pop();
},
'Program:exit': () => {
for (const knowledge of functionKnowledge.values()) {
const { node, lineCount } = knowledge;
if (lineCount > threshold && !isReactFunctionComponent(knowledge)) {
const functionLike = node;
context.report({
messageId: 'functionMaxLine',
data: {
lineCount: lineCount.toString(),
threshold: `${threshold}`,
},
loc: (0, index_js_1.getMainFunctionTokenLocation)(functionLike, functionLike.parent, context),
});
}
}
},
};
},
};
function getLocsNumber(loc, lines, commentLineNumbers) {
let lineCount = 0;
for (let i = loc.start.line - 1; i < loc.end.line; ++i) {
const line = lines[i];
const comment = commentLineNumbers.get(i + 1);
if (comment && isFullLineComment(line, i + 1, comment)) {
continue;
}
if (line.match(/^\s*$/u)) {
continue;
}
lineCount++;
}
return lineCount;
}
function getCommentLineNumbers(comments) {
const map = new Map();
comments.forEach(comment => {
if (comment.loc) {
for (let i = comment.loc.start.line; i <= comment.loc.end.line; i++) {
map.set(i, comment);
}
}
});
return map;
}
function isFullLineComment(line, lineNumber, comment) {
if (!comment.loc) {
return false;
}
const { start, end } = comment.loc;
const isFirstTokenOnLine = start.line === lineNumber && !line.slice(0, start.column).trim();
const isLastTokenOnLine = end.line === lineNumber && !line.slice(end.column).trim();
return (comment &&
(start.line < lineNumber || isFirstTokenOnLine) &&
(end.line > lineNumber || isLastTokenOnLine));
}
function isIIFE(node, parent) {
return (node.type === 'FunctionExpression' &&
parent &&
parent.type === 'CallExpression' &&
parent.callee === node);
}
function isReactFunctionComponent(knowledge) {
return knowledge.startsWithCapital && knowledge.returnsJSX;
}
function nameStartsWithCapital(node) {
const identifier = getIdentifierFromNormalFunction(node) ?? getIdentifierFromArrowFunction(node);
if (!identifier) {
return false;
}
return isIdentifierUppercase(identifier);
/**
* Picks `Foo` from: `let Foo = () => {}`
*/
function getIdentifierFromArrowFunction(node) {
if (node.type !== 'ArrowFunctionExpression') {
return null;
}
const parent = (0, index_js_1.getNodeParent)(node);
if (!parent) {
return null;
}
if (parent.type === 'VariableDeclarator') {
return parent.id;
}
else {
return null;
}
}
/**
* Picks `Foo` from:
* - `function Foo() {}`
* - `let bar = function Foo() {}`
*/
function getIdentifierFromNormalFunction(node) {
if (node.type === 'FunctionDeclaration' || node.type === 'FunctionExpression') {
return node.id;
}
}
function isIdentifierUppercase(node) {
return node.name.startsWith(node.name[0].toUpperCase());
}
}