eslint-plugin-sonarjs
Version:
SonarJS rules for ESLint
156 lines • 6.71 kB
JavaScript
;
/*
* eslint-plugin-sonarjs
* Copyright (C) 2018 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 GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* 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 GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
// https://jira.sonarsource.com/browse/RSPEC-4143
const equivalence_1 = require("../utils/equivalence");
const nodes_1 = require("../utils/nodes");
const locations_1 = require("../utils/locations");
const message = (index, line) => `Verify this is the index that was intended; "${index}" was already set on line ${line}.`;
const rule = {
meta: {
type: "problem",
schema: [
{
// internal parameter
enum: ["sonar-runtime"],
},
],
},
create(context) {
return {
SwitchCase(node) {
const switchCase = node;
checkStatements(switchCase.consequent);
},
BlockStatement(node) {
const block = node;
checkStatements(block.body);
},
Program(node) {
const program = node;
checkStatements(program.body);
},
};
function checkStatements(statements) {
const usedKeys = new Map();
let collection;
statements.forEach(statement => {
const keyWriteUsage = getKeyWriteUsage(statement);
if (keyWriteUsage) {
if (collection && !equivalence_1.areEquivalent(keyWriteUsage.collectionNode, collection, context.getSourceCode())) {
usedKeys.clear();
}
const sameKeyWriteUsage = usedKeys.get(keyWriteUsage.indexOrKey);
if (sameKeyWriteUsage && sameKeyWriteUsage.node.loc) {
const sameKeyWriteUsageLoc = sameKeyWriteUsage.node.loc;
const secondaryLocations = [locations_1.issueLocation(sameKeyWriteUsageLoc, sameKeyWriteUsageLoc, "Original value")];
locations_1.report(context, {
node: keyWriteUsage.node,
message: message(keyWriteUsage.indexOrKey, String(sameKeyWriteUsage.node.loc.start.line)),
}, secondaryLocations);
}
usedKeys.set(keyWriteUsage.indexOrKey, keyWriteUsage);
collection = keyWriteUsage.collectionNode;
}
else {
usedKeys.clear();
}
});
}
function getKeyWriteUsage(node) {
if (nodes_1.isExpressionStatement(node)) {
return arrayKeyWriteUsage(node.expression) || mapOrSetKeyWriteUsage(node.expression);
}
return undefined;
}
function arrayKeyWriteUsage(node) {
// a[b] = ...
if (isSimpleAssignment(node) && nodes_1.isMemberExpression(node.left) && node.left.computed) {
const { left, right } = node;
const index = extractIndex(left.property);
if (index !== undefined && !isUsed(left.object, right)) {
return {
collectionNode: left.object,
indexOrKey: index,
node,
};
}
}
return undefined;
}
function mapOrSetKeyWriteUsage(node) {
if (nodes_1.isCallExpression(node) && nodes_1.isMemberExpression(node.callee)) {
const propertyAccess = node.callee;
if (nodes_1.isIdentifier(propertyAccess.property)) {
const methodName = propertyAccess.property.name;
const addMethod = methodName === "add" && node.arguments.length === 1;
const setMethod = methodName === "set" && node.arguments.length === 2;
if (addMethod || setMethod) {
const key = extractIndex(node.arguments[0]);
if (key) {
return {
collectionNode: propertyAccess.object,
indexOrKey: key,
node,
};
}
}
}
}
return undefined;
}
function extractIndex(node) {
if (nodes_1.isLiteral(node)) {
const { value } = node;
return typeof value === "number" || typeof value === "string" ? String(value) : undefined;
}
else if (nodes_1.isIdentifier(node)) {
return node.name;
}
return undefined;
}
function isUsed(value, expression) {
const valueTokens = context.getSourceCode().getTokens(value);
const expressionTokens = context.getSourceCode().getTokens(expression);
const foundUsage = expressionTokens.find((token, index) => {
if (eq(token, valueTokens[0])) {
for (let expressionIndex = index, valueIndex = 0; expressionIndex < expressionTokens.length && valueIndex < valueTokens.length; expressionIndex++, valueIndex++) {
if (!eq(expressionTokens[expressionIndex], valueTokens[valueIndex])) {
break;
}
else if (valueIndex === valueTokens.length - 1) {
return true;
}
}
}
return false;
});
return foundUsage !== undefined;
}
},
};
function eq(token1, token2) {
return token1.value === token2.value;
}
function isSimpleAssignment(node) {
return nodes_1.isAssignmentExpression(node) && node.operator === "=";
}
module.exports = rule;
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