add rule limit-db-query-results

Author: Elise DUBILLOT

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - [#21](https://github.com/green-code-initiative/ecoCode-javascript/pull/21) Add rule `@ecocode/avoid-css-animations`
 - [#19](https://github.com/green-code-initiative/ecoCode-javascript/pull/19) add rule `@ecocode/no-empty-image-src-attribute`
+- [#18](https://github.com/green-code-initiative/ecoCode-javascript/pull/18) add rule `@ecocode/limit-db-query-results`
 - [#14](https://github.com/green-code-initiative/ecoCode-javascript/pull/14) Create SonarQube plugin
 - [#12](https://github.com/green-code-initiative/ecoCode-javascript/issues/12) Pack ESLint plugin into SonarQube plugin
 - [#16](https://github.com/green-code-initiative/ecoCode-javascript/pull/16) Use centralized rules specifications

eslint-plugin/README.md

@@ -60,6 +60,7 @@ Add `@ecocode` to the `plugins` section of your `.eslintrc`, followed by rules c
 | :------------------------------------------------------------------------------------- | :--------------------------------------------------------- | :- |
 | [avoid-css-animations](docs/rules/avoid-css-animations.md)                             | Avoid usage of CSS animations                              | ✅  |
 | [avoid-high-accuracy-geolocation](docs/rules/avoid-high-accuracy-geolocation.md)       | Avoid using high accuracy geolocation in web applications. | ✅  |
+| [limit-db-query-results](docs/rules/limit-db-query-results.md)                         | Should limit the number of returns for a SQL query         | ✅  |
 | [no-empty-image-src-attribute](docs/rules/no-empty-image-src-attribute.md)             | Disallow usage of image with empty source attribute        | ✅  |
 | [no-import-all-from-library](docs/rules/no-import-all-from-library.md)                 | Should not import all from library                         | ✅  |
 | [no-multiple-access-dom-element](docs/rules/no-multiple-access-dom-element.md)         | Disallow multiple access of same DOM element.              | ✅  |

eslint-plugin/docs/rules/limit-db-query-results.md

@@ -0,0 +1,23 @@
+# Should limit the number of returns for a SQL query (`@ecocode/limit-db-query-results`)
+
+⚠️ This rule _warns_ in the ✅ `recommended` config.
+
+<!-- end auto-generated rule header -->
+
+## Rule Details
+
+This rule aims at reducing CPU consumption by limiting the number of returns for a single SQL query.
+
+## Examples
+
+Examples of **non compliant** code for this rule:
+
+```js
+const query = "SELECT * FROM clients";
+```
+
+Examples of **compliant** code for this rule:
+
+```js
+const query = "SELECT columns FROM table_name FETCH FIRST number ROWS ONLY";
+```

eslint-plugin/lib/rules/limit-db-query-results.js

@@ -0,0 +1,55 @@
+/**
+ * Copyright (C) 2023 Green Code Initiative
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+"use strict";
+
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: "suggestion",
+    docs: {
+      description: "Should limit the number of returns for a SQL query",
+      category: "eco-design",
+      recommended: "warn",
+    },
+    messages: {
+      LimitTheNumberOfReturns:
+        "Try and limit the number of data returned for a single query (by using the LIMIT keyword for example)",
+    },
+    schema: [],
+  },
+  create(context) {
+    //list of limiting clauses to check against
+    const limitingClauses = ["LIMIT", "TOP", "ROW_NUMBER", "FETCH FIRST"];
+    return {
+      Literal: function (node) {
+        if (typeof node.value == "string") {
+          const query = node.value.toUpperCase();
+          if (
+            query.includes("SELECT") &&
+            query.includes("FROM") &&
+            !limitingClauses.some((clause) => query.includes(clause))
+          ) {
+            context.report({
+              node: node,
+              messageId: "LimitTheNumberOfReturns",
+            });
+          }
+        }
+      },
+    };
+  },
+};

eslint-plugin/tests/lib/rules/limit-db-query-results.js

@@ -0,0 +1,62 @@
+/**
+ * Copyright (C) 2023 Green Code Initiative
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+"use strict";
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const rule = require("../../../lib/rules/limit-db-query-results"),
+  RuleTester = require("eslint").RuleTester;
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 6,
+    sourceType: "module",
+  },
+});
+const expectedError = {
+  messageId: "LimitTheNumberOfReturns",
+  type: "Literal",
+};
+
+ruleTester.run("limit-db-query-results", rule, {
+  valid: [
+    `
+      const query = "SELECT * FROM customers LIMIT 10;";
+    `,
+    `
+      const query = "SELECT TOP 5 * FROM products;";
+    `,
+    `
+      const query = "SELECT * FROM orders FETCH FIRST 20 ROWS ONLY;";    
+    `,
+    `
+      const query = "WITH numbered_customers AS (SELECT *, ROW_NUMBER() OVER (ORDER BY customer_id) AS row_num FROM customers) SELECT * FROM numbered_customers WHERE row_num <= 50;";  
+    `,
+  ],
+
+  invalid: [
+    {
+      code: `const query = "SELECT * FROM bikes;";`,
+      errors: [expectedError],
+    },
+  ],
+});