eslint-plugin-sonarjs
Version:
SonarJS rules for ESLint
135 lines (134 loc) • 5.39 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/
*/
// https://sonarsource.github.io/rspec/#/rspec/S4322/javascript
Object.defineProperty(exports, "__esModule", { value: true });
exports.rule = void 0;
const index_js_1 = require("../helpers/index.js");
const meta_js_1 = require("./meta.js");
exports.rule = {
meta: (0, index_js_1.generateMeta)(meta_js_1.meta, {
hasSuggestions: true,
messages: {
useTypePredicate: 'Declare this function return type using type predicate "{{castedExpressionText}} is {{castedTypeText}}".',
suggestTypePredicate: 'Use type predicate',
},
}),
create(context) {
return {
"MethodDefinition[kind='method'] FunctionExpression"(node) {
checkFunctionLikeDeclaration(node, context);
},
FunctionDeclaration(node) {
checkFunctionLikeDeclaration(node, context);
},
};
},
};
function checkFunctionLikeDeclaration(functionDeclaration, context) {
if (functionDeclaration.returnType &&
functionDeclaration.returnType.typeAnnotation.type === 'TSTypePredicate') {
return;
}
const body = functionDeclaration.body;
const returnedExpression = getReturnedExpression(body);
if (!returnedExpression) {
return;
}
if (isInequalityBinaryExpression(returnedExpression)) {
const { left, right } = returnedExpression;
if ((0, index_js_1.isUndefined)(right)) {
checkCastedType(functionDeclaration, left, context);
}
else if ((0, index_js_1.isUndefined)(left)) {
checkCastedType(functionDeclaration, right, context);
}
}
else if (isBooleanCall(returnedExpression)) {
checkCastedType(functionDeclaration, returnedExpression.arguments[0], context);
}
else if (isNegation(returnedExpression) && isNegation(returnedExpression.argument)) {
checkCastedType(functionDeclaration, returnedExpression.argument.argument, context);
}
}
function getReturnedExpression(block) {
if (block && block.body.length === 1) {
const statement = block.body[0];
if (statement.type === 'ReturnStatement') {
return statement.argument;
}
}
return undefined;
}
function isInequalityBinaryExpression(returnExpression) {
return (returnExpression.type === 'BinaryExpression' &&
(returnExpression.operator === '!==' || returnExpression.operator === '!='));
}
function checkCastedType(node, expression, context) {
const sourceCode = context.sourceCode;
const castedType = getCastTupleFromMemberExpression(expression);
if (castedType && castedType[1].type !== 'TSAnyKeyword') {
const nOfParam = node.params.length;
if (nOfParam === 1 || (nOfParam === 0 && castedType[0].type === 'ThisExpression')) {
const castedExpressionText = sourceCode.getText(castedType[0]);
const castedTypeText = sourceCode.getText(castedType[1]);
const predicate = `: ${castedExpressionText} is ${castedTypeText}`;
const suggest = getTypePredicateSuggestion(node, context, predicate);
context.report({
messageId: 'useTypePredicate',
data: {
castedExpressionText,
castedTypeText,
},
loc: (0, index_js_1.getMainFunctionTokenLocation)(node, (0, index_js_1.getParent)(context, node), context),
suggest,
});
}
}
}
function getTypePredicateSuggestion(node, context, predicate) {
const suggestions = [];
let fix;
if (node.returnType) {
fix = fixer => fixer.replaceText(node.returnType, predicate);
}
else {
const closingParenthesis = context.sourceCode.getTokenBefore(node.body, token => token.value === ')');
fix = fixer => fixer.insertTextAfter(closingParenthesis, predicate);
}
suggestions.push({ messageId: 'suggestTypePredicate', fix });
return suggestions;
}
function getCastTupleFromMemberExpression(node) {
if (node.type === 'MemberExpression') {
const object = node.object;
if (object.type === 'TSAsExpression' || object.type === 'TSTypeAssertion') {
return [object.expression, object.typeAnnotation];
}
}
return undefined;
}
function isNegation(node) {
return node.type === 'UnaryExpression' && node.prefix && node.operator === '!';
}
function isBooleanCall(node) {
if (node.type === 'CallExpression') {
const callee = node.callee;
return node.arguments.length === 1 && callee.type === 'Identifier' && callee.name === 'Boolean';
}
return false;
}