JS-1387 Fix FP in S6767: props spread into JSX elements reported as unused (#6565)

Co-authored-by: Vibe Bot <vibe-bot@sonarsource.com>
Co-authored-by: Claude <noreply@anthropic.com>

Author: 3 people

its/ruling/src/test/expected/eigen/typescript-S6767.json

@@ -67,10 +67,6 @@
 "eigen:src/app/Scenes/Artwork/Components/CommercialButtons/BidButton.tsx": [
 20
 ],
-"eigen:src/app/Scenes/Artwork/Components/CommercialInformation.tsx": [
-34,
-37
-],
 "eigen:src/app/Scenes/Artwork/Components/FollowArtistLink.tsx": [
 11
 ],

packages/jsts/src/rules/S6767/decorator.ts

@@ -18,6 +18,7 @@
 
 import type { Rule, SourceCode } from 'eslint';
 import type estree from 'estree';
+import type { JSXSpreadAttribute } from 'estree-jsx';
 import { childrenOf } from '../helpers/ancestor.js';
 import { isIdentifier } from '../helpers/ast.js';
 import { interceptReportForReact } from '../helpers/decorators/interceptor.js';
@@ -70,6 +71,14 @@ function hasPropsCall(root: estree.Node, keys: SourceCode.VisitorKeys): boolean
     return true;
   }
 
+  // Check if this is a JSXSpreadAttribute with props (for {...props} or {...this.props} in JSX elements)
+  if (
+    root.type === 'JSXSpreadAttribute' &&
+    propsArgPatterns.some(p => p((root as unknown as JSXSpreadAttribute).argument))
+  ) {
+    return true;
+  }
+
   // Recursively check all children
   return childrenOf(root, keys).some(child => hasPropsCall(child, keys));
 }

packages/jsts/src/rules/S6767/unit.test.ts

@@ -129,6 +129,41 @@ class Button extends React.Component {
     });
   });
 
+  it('should not report props when spread into a JSX element via JSXSpreadAttribute', () => {
+    const ruleTester = new NoTypeCheckingRuleTester();
+
+    ruleTester.run('no-unused-prop-types', rule, {
+      valid: [
+        {
+          // FP: props forwarded via JSX spread; second object-literal spread resets upstream flag
+          code: `
+function Wrapper(props) {
+  return <div {...props} {...{extra: 'extra-value'}} />;
+}
+Wrapper.propTypes = {
+  onClick: PropTypes.func,
+};
+`,
+        },
+        {
+          // FP: class component this.props forwarded via JSX spread; second object-literal spread resets upstream flag
+          code: `
+class MyComponent extends React.Component {
+  render() {
+    return <Child {...this.props} {...{extra: 'extra-value'}} />;
+  }
+}
+MyComponent.propTypes = {
+  onClick: PropTypes.func,
+  label: PropTypes.string,
+};
+`,
+        },
+      ],
+      invalid: [],
+    });
+  });
+
   it('should exercise TypeScript type-checking paths (Strategy C in react helpers)', () => {
     const ruleTester = new RuleTester({
       parserOptions: {
@@ -289,6 +324,32 @@ Button.propTypes = { color: PropTypes.string };
     });
   });
 
+  it('upstream rule should report JSX spread FP pattern (sentinel: remove decorator if this fails)', () => {
+    // Confirms that the upstream eslint-plugin-react no-unused-prop-types rule DOES raise
+    // issues when {...props} or {...this.props} in JSX is followed by an object-literal
+    // spread that resets the upstream ignoreUnusedPropTypesValidation flag.
+    // If this test starts failing, the upstream rule has been fixed and the JSXSpreadAttribute
+    // handling in the S6767 decorator can be removed.
+    const upstreamRule = rules['no-unused-prop-types'];
+    const ruleTester = new NoTypeCheckingRuleTester();
+
+    ruleTester.run('no-unused-prop-types (upstream, JSX spread)', upstreamRule, {
+      valid: [],
+      invalid: [
+        {
+          // upstream resets ignoreUnusedPropTypesValidation when an object-literal spread follows the props spread
+          code: `
+function Wrapper(props) {
+  return <div {...props} {...{extra: 'extra-value'}} />;
+}
+Wrapper.propTypes = { onClick: PropTypes.func };
+`,
+          errors: 1,
+        },
+      ],
+    });
+  });
+
   it('upstream rule should NOT report state interface properties when TypeScript type info is available', () => {
     // Confirms that the upstream rule uses TypeScript type information to distinguish
     // state types from props types. AnchorState (used as the second type parameter of