diff options
Diffstat (limited to 'tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js')
-rw-r--r-- | tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js new file mode 100644 index 0000000000..29722a4f49 --- /dev/null +++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js @@ -0,0 +1,41 @@ +/** + * @fileoverview Warn when idempotent methods are called and their return value is unused. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +"use strict"; + +module.exports = { + meta: { + docs: { + url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-returnValue.html", + }, + schema: [], + type: "problem", + }, + + create(context) { + return { + ExpressionStatement(node) { + if ( + node.expression?.type != "CallExpression" || + node.expression.callee?.type != "MemberExpression" || + node.expression.callee.property?.type != "Identifier" || + !["concat", "join", "slice"].includes( + node.expression.callee.property?.name + ) + ) { + return; + } + + context.report({ + node, + message: `{Array/String}.${node.expression.callee.property.name} doesn't modify the instance in-place`, + }); + }, + }; + }, +}; |