eslint-plugin-sonarjs
Version:
SonarJS rules for ESLint
128 lines • 5.76 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-1871
const nodes_1 = require("../utils/nodes");
const equivalence_1 = require("../utils/equivalence");
const conditions_1 = require("../utils/conditions");
const locations_1 = require("../utils/locations");
const MESSAGE = "This {{type}}'s code block is the same as the block for the {{type}} on line {{line}}.";
const rule = {
meta: {
type: "problem",
schema: [
{
// internal parameter
enum: ["sonar-runtime"],
},
],
},
create(context) {
return {
IfStatement(node) {
visitIfStatement(node);
},
SwitchStatement(node) {
visitSwitchStatement(node);
},
};
function visitIfStatement(ifStmt) {
const parent = nodes_1.getParent(context);
if (nodes_1.isIfStatement(parent)) {
return;
}
const { branches, endsWithElse } = conditions_1.collectIfBranches(ifStmt);
if (allEquivalentWithoutDefault(branches, endsWithElse)) {
branches.slice(1).forEach((branch, i) => reportIssue(branch, branches[i], "branch"));
return;
}
for (let i = 1; i < branches.length; i++) {
if (hasRequiredSize([branches[i]])) {
for (let j = 0; j < i; j++) {
if (compareIfBranches(branches[i], branches[j])) {
break;
}
}
}
}
}
function visitSwitchStatement(switchStmt) {
const { cases } = switchStmt;
const { endsWithDefault } = conditions_1.collectSwitchBranches(switchStmt);
const nonEmptyCases = cases.filter(c => conditions_1.takeWithoutBreak(expandSingleBlockStatement(c.consequent)).length > 0);
const casesWithoutBreak = nonEmptyCases.map(c => conditions_1.takeWithoutBreak(expandSingleBlockStatement(c.consequent)));
if (allEquivalentWithoutDefault(casesWithoutBreak, endsWithDefault)) {
nonEmptyCases.slice(1).forEach((caseStmt, i) => reportIssue(caseStmt, nonEmptyCases[i], "case"));
return;
}
for (let i = 1; i < cases.length; i++) {
const firstClauseWithoutBreak = conditions_1.takeWithoutBreak(expandSingleBlockStatement(cases[i].consequent));
if (hasRequiredSize(firstClauseWithoutBreak)) {
for (let j = 0; j < i; j++) {
const secondClauseWithoutBreak = conditions_1.takeWithoutBreak(expandSingleBlockStatement(cases[j].consequent));
if (equivalence_1.areEquivalent(firstClauseWithoutBreak, secondClauseWithoutBreak, context.getSourceCode())) {
reportIssue(cases[i], cases[j], "case");
break;
}
}
}
}
}
function hasRequiredSize(nodes) {
if (nodes.length > 0) {
const tokens = [
...context.getSourceCode().getTokens(nodes[0]),
...context.getSourceCode().getTokens(nodes[nodes.length - 1]),
].filter(token => token.value !== "{" && token.value !== "}");
return tokens.length > 0 && tokens[tokens.length - 1].loc.end.line > tokens[0].loc.start.line;
}
return false;
}
function compareIfBranches(a, b) {
const equivalent = equivalence_1.areEquivalent(a, b, context.getSourceCode());
if (equivalent && b.loc) {
reportIssue(a, b, "branch");
}
return equivalent;
}
function expandSingleBlockStatement(nodes) {
if (nodes.length === 1) {
const node = nodes[0];
if (nodes_1.isBlockStatement(node)) {
return node.body;
}
}
return nodes;
}
function allEquivalentWithoutDefault(branches, endsWithDefault) {
return (!endsWithDefault &&
branches.length > 1 &&
branches.slice(1).every((branch, index) => equivalence_1.areEquivalent(branch, branches[index], context.getSourceCode())));
}
function reportIssue(node, equivalentNode, type) {
const equivalentNodeLoc = equivalentNode.loc;
locations_1.report(context, { message: MESSAGE, data: { type, line: String(equivalentNode.loc.start.line) }, node }, [
locations_1.issueLocation(equivalentNodeLoc, equivalentNodeLoc, "Original"),
]);
}
},
};
module.exports = rule;
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