Add rule no-imported-number-format-library (GCI535)

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- [#84](https://github.com/green-code-initiative/creedengo-javascript/pull/84) Add rule GCI535 "No imported number format library"
+
 ## [3.1.0] - 2026-05-10
 
 ### Added

eslint-plugin/README.md

@@ -90,6 +90,7 @@ export default [
 | [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-imported-number-format-library](docs/rules/no-imported-number-format-library.md)           | You should not format number with an external library     | ✅  |
 | [no-multiple-access-dom-element](docs/rules/no-multiple-access-dom-element.md)                 | Disallow multiple access of same DOM element              | ✅  |
 | [no-multiple-style-changes](docs/rules/no-multiple-style-changes.md)                           | Disallow multiple style changes at once                   | ✅  |
 | [no-torch](docs/rules/no-torch.md)                                                             | Should not programmatically enable torch mode             | ✅  |

eslint-plugin/docs/rules/no-imported-number-format-library.md

@@ -0,0 +1,63 @@
+# @creedengo/no-imported-number-format-library
+
+📝 You should not format number with an external library.
+
+⚠️ This rule _warns_ in the ✅ `recommended` config.
+
+<!-- end auto-generated rule header -->
+
+## Why is this an issue?
+
+Importing an external library for lightweight operations increases overall size of the program.
+Using native methods instead reduces the amount of memory and storage to run and store the application.
+This is especially critical in environments with limited resources, such as on mobile devices or in web applications
+where bandwidth and download times matter.
+
+Smaller programs generally have better runtime performance.
+Reducing the number of unnecessary modules minimizes the amount of code that needs to be interpreted or compiled,
+leading to faster execution and improved overall performance.
+
+Depending on less external dependencies also increases the maintainability and security of your program.
+
+## Examples
+
+**Example with the [numbro](https://numbrojs.com/) library, when you use
+`format` method.**
+
+```js
+// Example with numbro (not compliant)
+import numbro from "numbro";
+
+numbro.setLanguage("en-GB");
+var string = numbro(1000).format({
+  thousandSeparated: true,
+}); // '1,000'
+
+// Example with numerable (not compliant)
+import { format } from "numerable";
+format(1000, "0,0");
+
+// Example with Intl (compliant)
+new Intl.NumberFormat("en-GB").format(1000); // '1,000'
+```
+
+## Limitations
+
+As for now, only two libraries are handled by this rule :
+
+- [numbro](https://www.npmjs.com/package/numbro)
+- [numerable](https://www.npmjs.com/package/numerable)
+
+Some candidates for the future developments are :
+
+- [javascript-number-formatter](https://www.npmjs.com/package/number-format.js)
+- [numeraljs](https://www.npmjs.com/package/numeral)
+- [formatjs](https://www.npmjs.com/package/@formatjs/intl)
+
+It’s more likely this rule won’t ever be exhaustive.
+
+## Resources
+
+### Documentation
+
+- [Mozilla Web Technology for Developers](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat)

eslint-plugin/lib/rules/no-imported-number-format-library.js

@@ -0,0 +1,85 @@
+/*
+ * creedengo JavaScript plugin - Provides rules to reduce the environmental footprint of your JavaScript programs
+ * Copyright © 2023 Green Code Initiative (https://green-code-initiative.org)
+ *
+ * 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: "You should not format number with an external library",
+      category: "eco-design",
+      recommended: "warn",
+    },
+    messages: {
+      ShouldNotUseImportedNumberFormatLibrary:
+        "You should not format number with an external library",
+    },
+    schema: [],
+  },
+
+  create: function (context) {
+    let variablesNumbro = [];
+
+    const errorReport = (node) => ({
+      node,
+      messageId: "ShouldNotUseImportedNumberFormatLibrary",
+    });
+
+    return {
+      VariableDeclarator(node) {
+        if (
+          node.init?.callee?.name === "numbro" &&
+          node.id.type === "Identifier"
+        ) {
+          variablesNumbro.push(node.id.name);
+        }
+      },
+      CallExpression(node) {
+        const formatIsCalledOnANumbroTypeVariable =
+          node.callee.type === "MemberExpression" &&
+          variablesNumbro.includes(node.callee.object.name) &&
+          node.callee.property.name === "format";
+        if (formatIsCalledOnANumbroTypeVariable) {
+          context.report(errorReport(node.callee.property));
+        }
+        let formatIsCalledOnNumbroInstance =
+          node.parent.type === "MemberExpression" &&
+          node.callee.name === "numbro" &&
+          node.parent.property.name === "format";
+        if (formatIsCalledOnNumbroInstance) {
+          context.report(errorReport(node.parent.property));
+        }
+      },
+      ImportDeclaration(node) {
+        const importedLibraryName = node.source.value;
+        if (importedLibraryName === "numerable") {
+          const formatSpecifier = node.specifiers.find(
+            (specifier) =>
+              specifier.type === "ImportSpecifier" &&
+              specifier.imported.name === "format",
+          );
+          if (formatSpecifier) {
+            context.report(errorReport(formatSpecifier));
+          }
+        }
+      },
+    };
+  },
+};

eslint-plugin/tests/lib/rules/no-imported-number-format-library.test.js

@@ -0,0 +1,95 @@
+/*
+ * creedengo JavaScript plugin - Provides rules to reduce the environmental footprint of your JavaScript programs
+ * Copyright © 2023 Green Code Initiative (https://green-code-initiative.org)
+ *
+ * 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/no-imported-number-format-library");
+const { RuleTester } = require("eslint");
+const { describe, it } = require("node:test");
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({
+  languageOptions: {
+    ecmaVersion: 6,
+    sourceType: "module",
+  },
+});
+
+const expectedIdentifierError = {
+  messageId: "ShouldNotUseImportedNumberFormatLibrary",
+};
+const expectedImportError = {
+  messageId: "ShouldNotUseImportedNumberFormatLibrary",
+};
+
+const tests = {
+  valid: [
+    "new Intl.NumberFormat().format(1000);",
+    "numbro(1000).add(5);",
+    `
+    const number = numbro(1000);
+    const number2 = numbro(2000);
+    number2.add(1000);
+    `,
+    "import { parse } from 'numerable';",
+    "import { format } from 'date-fns';",
+    "import mysql from 'mysql2';",
+  ],
+  invalid: [
+    {
+      code: "numbro(1000).format({thousandSeparated: true});",
+      errors: [expectedIdentifierError],
+    },
+    {
+      code: `
+      const number = numbro(1000);
+      number.format({thousandSeparated: true});
+      `,
+      errors: [expectedIdentifierError],
+    },
+    {
+      code: `
+      const number = numbro(1000);
+      const number2 = numbro(2000);
+      number.format({thousandSeparated: true});
+      `,
+      errors: [expectedIdentifierError],
+    },
+    {
+      code: "import { format } from 'numerable';",
+      errors: [expectedImportError],
+    },
+    {
+      code: "import { format as myFormat} from 'numerable';",
+      errors: [expectedImportError],
+    },
+  ],
+};
+
+describe("no-imported-number-format-library", () => {
+  it("no-imported-number-format-library", () => {
+    ruleTester.run("no-imported-number-format-library", rule, tests);
+  });
+});

sonar-plugin/src/main/java/org/greencodeinitiative/creedengo/javascript/CheckList.java

@@ -42,6 +42,7 @@ public static List<Class<? extends EslintHook>> getAllHooks() {
                 LimitDbQueryResult.class,
                 NoEmptyImageSrcAttribute.class,
                 NoImportAllFromLibrary.class,
+                NoImportedNumberFormatLibrary.class,
                 NoMultipleAccessDomElement.class,
                 NoMultipleStyleChanges.class,
                 NoTorch.class,

sonar-plugin/src/main/java/org/greencodeinitiative/creedengo/javascript/checks/NoImportedNumberFormatLibrary.java

@@ -0,0 +1,37 @@
+/*
+ * Creedengo JavaScript plugin - Provides rules to reduce the environmental footprint of your JavaScript programs
+ * Copyright © 2023 Green Code Initiative (https://green-code-initiative.org)
+ *
+ * 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/>.
+ */
+package org.greencodeinitiative.creedengo.javascript.checks;
+
+import org.sonar.check.Rule;
+import org.sonar.plugins.javascript.api.EslintHook;
+import org.sonar.plugins.javascript.api.JavaScriptRule;
+import org.sonar.plugins.javascript.api.TypeScriptRule;
+
+@JavaScriptRule
+@TypeScriptRule
+@Rule(key = NoImportedNumberFormatLibrary.RULE_KEY)
+public class NoImportedNumberFormatLibrary implements EslintHook {
+
+    public static final String RULE_KEY = "GCI535";
+
+    @Override
+    public String eslintKey() {
+        return "@creedengo/no-imported-number-format-library";
+    }
+
+}

sonar-plugin/src/main/resources/org/greencodeinitiative/creedengo/profiles/javascript_profile.json

@@ -13,6 +13,7 @@
     "GCI36",
     "GCI505",
     "GCI523",
-    "GCI530"
+    "GCI530",
+    "GCI535"
   ]
 }

test-project/src/no-imported-number-format-library.js

@@ -0,0 +1,14 @@
+import numbro from "numbro";
+import { parse, format } from "numerable"; // Non-compliant: usage of external library to format number
+
+numbro(1000).format({thousandSeparated: true}); // Non-compliant: usage of external library to format number
+
+let variable = numbro(1000);
+variable.format({thousandSeparated: true}); // Non-compliant: usage of external library to format number
+
+numbro(2000).add(1000); // Compliant
+
+new Intl.NumberFormat().format(1000); // Compliant
+
+format(28);
+parse("29"); // Compliant