Fix FP S6749 (jsx-no-useless-fragment): Ignore empty React fragments

its/ruling/src/test/expected/js/fireact/javascript-S6749.json

@@ -1,7 +1,4 @@
 {
-"fireact:src/components/Loader/index.js": [
-24
-],
 "fireact:src/components/Logo/index.js": [
 6
 ],
@@ -14,9 +11,6 @@
 "fireact:src/pages/auth/accounts/DeleteAccount/index.js": [
 57
 ],
-"fireact:src/pages/auth/accounts/PaymentList/index.js": [
-72
-],
 "fireact:src/pages/auth/accounts/PaymentMethod/index.js": [
 131
 ]

its/ruling/src/test/expected/ts/courselit/typescript-S6749.json

@@ -5,23 +5,7 @@
 "courselit:apps/web/components/public/base-layout/scaffold/drawer-content.tsx": [
 57
 ],
-"courselit:apps/web/components/public/base-layout/template/section.tsx": [
-40
-],
-"courselit:apps/web/components/public/checkout/index.tsx": [
-32,
-33
-],
-"courselit:apps/web/components/public/code-injector.tsx": [
-45
-],
-"courselit:apps/web/components/public/items.tsx": [
-90
-],
 "courselit:apps/web/components/public/purchase-status.tsx": [
 105
-],
-"courselit:packages/common-widgets/src/tagged-content/widget.tsx": [
-77
 ]
 }

its/ruling/src/test/expected/ts/eigen/typescript-S6749.json

@@ -1,63 +1,26 @@
 {
-"eigen:src/app/Components/AuctionResultsList.tsx": [
-90
-],
 "eigen:src/app/Components/States/ZeroState.tsx": [
 17,
 27
 ],
-"eigen:src/app/Components/StickyTabPage/StickyTabPage.tsx": [
-51
-],
-"eigen:src/app/Scenes/Artist/SearchCriteria.tests.tsx": [
-18,
-33,
-52,
-57,
-66
-],
 "eigen:src/app/Scenes/Artwork/Components/CommercialButtons/InquiryModal.tsx": [
 77
 ],
-"eigen:src/app/Scenes/Artwork/Components/CommercialEditionSetInformation.tsx": [
-57
-],
 "eigen:src/app/Scenes/City/Components/SavedEventSection/index.tsx": [
 46
 ],
-"eigen:src/app/Scenes/Home/Components/AuctionResultsRail.tsx": [
-51
-],
 "eigen:src/app/Scenes/Home/Components/FairsRail.tsx": [
 57
 ],
-"eigen:src/app/Scenes/Home/Home.tsx": [
-206
-],
-"eigen:src/app/Scenes/MyBids/MyBids.tsx": [
-114
-],
 "eigen:src/app/Scenes/MyCollection/Screens/Artwork/Components/ArtworkInsights/MyCollectionArtworkArtistAuctionResults.tsx": [
 50
 ],
-"eigen:src/app/Scenes/MyCollection/Screens/Artwork/Components/MyCollectionArtworkHeader.tsx": [
-112
-],
-"eigen:src/app/Scenes/SavedAddresses/SavedAddresses.tsx": [
-165
-],
 "eigen:src/app/Scenes/SavedSearchAlertsList/Components/SavedSearchAlertsListPlaceholder.tsx": [
 8
 ],
 "eigen:src/app/Scenes/Search/components/placeholders/AlgoliaSearchPlaceholder.tsx": [
 15
 ],
-"eigen:src/app/Scenes/SellWithArtsy/SubmitArtwork/SubmitArtwork.tsx": [
-217
-],
-"eigen:src/app/Scenes/Tag/Tag.tsx": [
-65
-],
 "eigen:src/palette/elements/CollapsibleMenuItem/CollapsibleMenuItem.stories.tsx": [
 154
 ],

packages/jsts/src/rules/S6749/decorator.ts

@@ -0,0 +1,46 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2023 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/S6749/javascript
+
+import { Rule } from 'eslint';
+import { interceptReport } from '../helpers';
+
+/**
+ * The core implementation of the rule reports on empty React fragments.
+ * Also, one of the two issue messages include a Unicode character.
+ */
+export function decorate(rule: Rule.RuleModule): Rule.RuleModule {
+  rule.meta!.hasSuggestions = true;
+  rule.meta!.messages = {
+    ...rule.meta!.messages,
+    /* Map to a more friendly message */
+    NeedsMoreChildren: 'A fragment with only one child is redundant.',
+  };
+  return interceptReport(rule, (context, descriptor) => {
+    const { node } = descriptor as any;
+
+    /* Ignore empty fragments */
+    if (node.type === 'JSXFragment' && node.children.length === 0) {
+      return;
+    }
+
+    context.report(descriptor);
+  });
+}

packages/jsts/src/rules/S6749/index.ts

@@ -0,0 +1,23 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2023 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 { rules } from 'eslint-plugin-react';
+import { decorate } from './decorator';
+
+export const rule = decorate(rules['jsx-no-useless-fragment']);

packages/jsts/src/rules/S6749/unit.test.ts

@@ -0,0 +1,43 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2023 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 { RuleTester } from 'eslint';
+import { rule } from './';
+
+const ruleTester = new RuleTester({
+  parserOptions: { ecmaVersion: 2018, ecmaFeatures: { jsx: true } },
+});
+ruleTester.run('Redundant React fragments should be removed', rule, {
+  valid: [
+    {
+      code: `function Empty() { return <></>; }`,
+    },
+  ],
+  invalid: [
+    {
+      code: `function Child() { return <><img /></>; }`,
+      output: `function Child() { return <img />; }`,
+      errors: [
+        {
+          message: 'A fragment with only one child is redundant.',
+        },
+      ],
+    },
+  ],
+});

packages/jsts/src/rules/index.ts

@@ -108,6 +108,7 @@ import { rule as S5659 } from './S5659'; // insecure-jwt-token
 import { rule as S3415 } from './S3415'; // inverted-assertion-arguments
 import { rule as S6477 } from './S6477'; // jsx-key
 import { rule as S6481 } from './S6481'; // jsx-no-constructed-context-values
+import { rule as S6749 } from './S6749'; // jsx-no-useless-fragment
 import { rule as S1439 } from './S1439'; // label-position
 import { rule as S5148 } from './S5148'; // link-with-target-blank
 import { rule as S4622 } from './S4622'; // max-union-size
@@ -381,6 +382,7 @@ rules['insecure-jwt-token'] = S5659;
 rules['inverted-assertion-arguments'] = S3415;
 rules['jsx-key'] = S6477;
 rules['jsx-no-constructed-context-values'] = S6481;
+rules['jsx-no-useless-fragment'] = S6749;
 rules['label-position'] = S1439;
 rules['link-with-target-blank'] = S5148;
 rules['max-union-size'] = S4622;