Fix FP S6479 (no-array-index-key) - Allow keys combining index and other values

packages/jsts/src/rules/S6479/index.ts

@@ -0,0 +1,20 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2024 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.
+ */
+export { rule } from './rule';

packages/jsts/src/rules/S6479/rule.ts

@@ -0,0 +1,48 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2024 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://sonarsource.github.io/rspec/#/rspec/S6486/javascript
+
+// inspired from `no-array-index` from `eslint-plugin-react`:
+// https://github.com/jsx-eslint/eslint-plugin-react/blob/0a2f6b7e9df32215fcd4e3061ec69ea3f2eef793/lib/rules/no-array-index-key.js#L16
+
+import { rules } from 'eslint-plugin-react';
+import { interceptReportForReact } from '../helpers';
+import { Rule } from 'eslint';
+
+export const rule = interceptReportForReact(
+  rules['no-array-index-key'],
+  (context, reportDescriptor) => {
+    const { node } = reportDescriptor as Rule.ReportDescriptor & {
+      node: Rule.Node;
+    };
+
+    if (node.type === 'BinaryExpression') {
+      return;
+    }
+
+    // we got a report from ESLint, hence one of the expressions included in the literal _is_ the array index
+    // we can then safely bail if there is another expression in the literal
+    if (node.type === 'TemplateLiteral' && node.expressions.length > 1) {
+      return;
+    }
+
+    context.report(reportDescriptor);
+  },
+);

packages/jsts/src/rules/S6479/unit.test.ts

@@ -0,0 +1,109 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2024 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.
+ */
+import { JavaScriptRuleTester } from '../tools';
+import { rule } from './rule';
+
+const ruleTester = new JavaScriptRuleTester();
+
+ruleTester.run('', rule, {
+  valid: [
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    return <>{items.map((item, index) => {
+      return <div key={item.id + '' + index}/>;
+    })}</>;
+}
+`,
+    },
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    return <>{items.map((item, index) => {
+      return <div key={\`\${item.id}-\${index}\`}/>;
+    })}</>;
+}
+`,
+    },
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    const renderItems = () => {
+      let i = 0;
+
+      return items.map(() => {
+        return <div key={i++}/>;
+      });
+    }
+
+    return <>{renderItems()}</>;
+}
+`,
+    },
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    const computeKey = (item, index) => {
+      return item.id + '' + index;
+    }
+
+    return <>{items.map((item, index) => {
+      return <div key={computeKey(item, index)}/>;
+    })}</>;
+}
+`,
+    },
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    const computeKey = (index) => {
+      return index;
+    }
+
+    return <>{items.map((_item, index) => {
+      return <div key={computeKey(index)}/>;
+    })}</>;
+} // this test should trigger the rule but it seems ESLint is missing it
+`,
+    },
+  ],
+  invalid: [
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    return <>{items.map((item, index) => {
+      return <div key={index}>{item.id}</div>;
+    })}</>;
+}
+`,
+      errors: 1,
+    },
+    {
+      code: `
+export const MyComponent = ({items}) => {
+    return <>{items.map((item, index) => {
+      return <div key={\`\${index}\`}>{item.id}</div>;
+    })}</>;
+}
+`,
+      errors: 1,
+    },
+  ],
+});