JS-1113 Fix FP on S7759 for polyfill fallback using Date#getTime() for Date.now()

its/ruling/src/test/expected/jsts/ace/javascript-S7759.json

@@ -1,12 +1,8 @@
 {
 "ace:lib/ace/mode/javascript/jshint.js": [
-157,
-3188
+157
 ],
 "ace:src/background_tokenizer.js": [
 56
-],
-"ace:tool/perf-test.html": [
-61
 ]
 }

its/ruling/src/test/expected/jsts/qunit/javascript-S7759.json

@@ -2,11 +2,5 @@
 "qunit:reporter/diff.js": [
 62,
 618
-],
-"qunit:src/core/utilities.js": [
-7
-],
-"qunit:test/autostart.html": [
-16
 ]
 }

packages/jsts/src/rules/README.md

@@ -557,7 +557,6 @@ SonarJS uses some rules are not shipped in this ESLint plugin to avoid duplicati
 | [S7756](https://sonarsource.github.io/rspec/#/rspec/S7756/javascript) | [unicorn/prefer-blob-reading-methods](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-blob-reading-methods.md)                                            |
 | [S7757](https://sonarsource.github.io/rspec/#/rspec/S7757/javascript) | [unicorn/prefer-class-fields](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-class-fields.md)                                                            |
 | [S7758](https://sonarsource.github.io/rspec/#/rspec/S7758/javascript) | [unicorn/prefer-code-point](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-code-point.md)                                                                |
-| [S7759](https://sonarsource.github.io/rspec/#/rspec/S7759/javascript) | [unicorn/prefer-date-now](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-date-now.md)                                                                    |
 | [S7760](https://sonarsource.github.io/rspec/#/rspec/S7760/javascript) | [unicorn/prefer-default-parameters](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-default-parameters.md)                                                |
 | [S7761](https://sonarsource.github.io/rspec/#/rspec/S7761/javascript) | [unicorn/prefer-dom-node-dataset](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-dom-node-dataset.md)                                                    |
 | [S7762](https://sonarsource.github.io/rspec/#/rspec/S7762/javascript) | [unicorn/prefer-dom-node-remove](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-dom-node-remove.md)                                                      |
@@ -659,6 +658,7 @@ The following rules are used in SonarJS but not available in this ESLint plugin.
 | [S7727](https://sonarsource.github.io/rspec/#/rspec/S7727/javascript) | [unicorn/no-array-callback-reference](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/no-array-callback-reference.md)                                                                                                                                                                                                                                        |
 | [S7728](https://sonarsource.github.io/rspec/#/rspec/S7728/javascript) | [unicorn/no-array-for-each](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/no-array-for-each.md)                                                                                                                                                                                                                                                            |
 | [S7755](https://sonarsource.github.io/rspec/#/rspec/S7755/javascript) | [unicorn/prefer-at](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-at.md)                                                                                                                                                                                                                                                                            |
+| [S7759](https://sonarsource.github.io/rspec/#/rspec/S7759/javascript) | [unicorn/prefer-date-now](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-date-now.md)                                                                                                                                                                                                                                                                |
 | [S7763](https://sonarsource.github.io/rspec/#/rspec/S7763/javascript) | [unicorn/prefer-export-from](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/HEAD/docs/rules/prefer-export-from.md)                                                                                                                                                                                                                                                          |
 
 <!--- end decorated rules -->

packages/jsts/src/rules/S7759/decorator.ts

@@ -0,0 +1,201 @@
+/*
+ * SonarQube JavaScript Plugin
+ * Copyright (C) 2011-2025 SonarSource Sàrl
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the Sonar Source-Available License Version 1, as published by SonarSource SA.
+ *
+ * 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 Sonar Source-Available License for more details.
+ *
+ * You should have received a copy of the Sonar Source-Available License
+ * along with this program; if not, see https://sonarsource.com/license/ssal/
+ */
+// https://sonarsource.github.io/rspec/#/rspec/S7759/javascript
+
+import type { Rule } from 'eslint';
+import type estree from 'estree';
+import { generateMeta, interceptReport, isMemberExpression } from '../helpers/index.js';
+import * as meta from './generated-meta.js';
+
+/**
+ * Decorates the unicorn/prefer-date-now rule to filter out reports where
+ * `new Date().getTime()`, `+(new Date())`, or similar patterns are used
+ * inside a polyfill fallback that checks for `Date.now` availability.
+ */
+export function decorate(rule: Rule.RuleModule): Rule.RuleModule {
+  return interceptReport(
+    {
+      ...rule,
+      meta: generateMeta(meta, rule.meta),
+    },
+    (context, descriptor) => {
+      const node = (descriptor as { node?: estree.Node }).node;
+      if (!node) {
+        context.report(descriptor);
+        return;
+      }
+
+      // Check if the node is inside a polyfill pattern
+      if (isInsidePolyfillPattern(node, context)) {
+        return; // Suppress the report
+      }
+
+      context.report(descriptor);
+    },
+  );
+}
+
+/**
+ * Checks if the flagged node is inside a Date.now polyfill pattern.
+ */
+function isInsidePolyfillPattern(node: estree.Node, context: Rule.RuleContext): boolean {
+  const ancestors = context.sourceCode.getAncestors(node);
+
+  for (const ancestor of ancestors) {
+    // Pattern 1: Date.now || function() { return new Date().getTime(); }
+    if (isLogicalOrPolyfill(node, ancestor, ancestors)) {
+      return true;
+    }
+
+    // Pattern 2: Date.now ? Date.now() : +(new Date())
+    if (isTernaryPolyfill(node, ancestor, ancestors)) {
+      return true;
+    }
+
+    // Pattern 3: if (!Date.now) { Date.now = function() { ... }; }
+    if (isIfStatementPolyfill(node, ancestor, ancestors)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * Checks for LogicalExpression pattern: Date.now || fallback
+ * The flagged node should be in the right (fallback) branch.
+ */
+function isLogicalOrPolyfill(
+  node: estree.Node,
+  ancestor: estree.Node,
+  ancestors: estree.Node[],
+): boolean {
+  if (ancestor.type !== 'LogicalExpression' || ancestor.operator !== '||') {
+    return false;
+  }
+
+  // Check if left operand is Date.now
+  if (!isDateNow(ancestor.left)) {
+    return false;
+  }
+
+  // Check if flagged node is in the right operand (fallback branch)
+  return isDescendantOf(node, ancestor.right, ancestors);
+}
+
+/**
+ * Checks for ConditionalExpression pattern: Date.now ? Date.now() : fallback
+ * The flagged node should be in the alternate (fallback) branch.
+ */
+function isTernaryPolyfill(
+  node: estree.Node,
+  ancestor: estree.Node,
+  ancestors: estree.Node[],
+): boolean {
+  if (ancestor.type !== 'ConditionalExpression') {
+    return false;
+  }
+
+  // Check if test references Date.now (truthy check)
+  if (!isDateNow(ancestor.test)) {
+    return false;
+  }
+
+  // Check if flagged node is in the alternate (fallback) branch
+  return isDescendantOf(node, ancestor.alternate, ancestors);
+}
+
+/**
+ * Checks for IfStatement pattern: if (!Date.now) { Date.now = ...; }
+ * The flagged node should be inside the consequent block that assigns to Date.now.
+ */
+function isIfStatementPolyfill(
+  node: estree.Node,
+  ancestor: estree.Node,
+  ancestors: estree.Node[],
+): boolean {
+  if (ancestor.type !== 'IfStatement') {
+    return false;
+  }
+
+  // Check if test is !Date.now
+  const { test } = ancestor;
+  if (test.type !== 'UnaryExpression' || test.operator !== '!') {
+    return false;
+  }
+
+  if (!isDateNow(test.argument)) {
+    return false;
+  }
+
+  // Check if consequent contains an assignment to Date.now
+  if (!containsDateNowAssignment(ancestor.consequent)) {
+    return false;
+  }
+
+  // Check if flagged node is in the consequent (not in the alternate/else branch)
+  return isDescendantOf(node, ancestor.consequent, ancestors);
+}
+
+/**
+ * Checks if a node is the `Date.now` member expression.
+ */
+function isDateNow(node: estree.Node): boolean {
+  return isMemberExpression(node, 'Date', 'now');
+}
+
+/**
+ * Checks if a node or its descendants contain an assignment to Date.now.
+ */
+function containsDateNowAssignment(node: estree.Node): boolean {
+  if (node.type === 'ExpressionStatement') {
+    return containsDateNowAssignment(node.expression);
+  }
+
+  if (node.type === 'AssignmentExpression') {
+    return isDateNow(node.left);
+  }
+
+  if (node.type === 'BlockStatement') {
+    return node.body.some(stmt => containsDateNowAssignment(stmt));
+  }
+
+  return false;
+}
+
+/**
+ * Checks if `node` is a descendant of `potentialAncestor` using the ancestors array.
+ */
+function isDescendantOf(
+  node: estree.Node,
+  potentialAncestor: estree.Node,
+  ancestors: estree.Node[],
+): boolean {
+  // If node is exactly potentialAncestor, it's a descendant (trivially)
+  if (node === potentialAncestor) {
+    return true;
+  }
+
+  // Walk up from node through ancestors to see if we pass through potentialAncestor
+  for (const anc of ancestors) {
+    if (anc === potentialAncestor) {
+      return true;
+    }
+  }
+
+  return false;
+}

packages/jsts/src/rules/S7759/index.ts

@@ -15,4 +15,6 @@
  * along with this program; if not, see https://sonarsource.com/license/ssal/
  */
 import { rules } from '../external/unicorn.js';
-export const rule = rules['prefer-date-now'];
+import { decorate } from './decorator.js';
+
+export const rule = decorate(rules['prefer-date-now']);

packages/jsts/src/rules/S7759/meta.ts

@@ -15,7 +15,7 @@
  * along with this program; if not, see https://sonarsource.com/license/ssal/
  */
 // https://sonarsource.github.io/rspec/#/rspec/S7759/javascript
-export const implementation = 'external';
+export const implementation = 'decorated';
 export const eslintId = 'prefer-date-now';
-export const externalPlugin = 'unicorn';
+export const externalRules = [{ externalPlugin: 'unicorn', externalRule: 'prefer-date-now' }];
 export const quickFixMessage = 'Replace with Date.now()';