Add no-unsafe-promise-all-settled-values rule

docs/rules/no-unsafe-promise-all-settled-values.md

@@ -0,0 +1,42 @@
+# no-unsafe-promise-all-settled-values
+
+📝 Disallow reading `.value` from `Promise.allSettled()` results without a fulfilled status guard.
+
+💼 This rule is enabled in the following [configs](https://github.com/sindresorhus/eslint-plugin-unicorn#recommended-config): ✅ `recommended`, ☑️ `unopinionated`.
+
+<!-- end auto-generated rule header -->
+<!-- Do not manually modify this header. Run: `npm run fix:eslint-docs` -->
+
+`Promise.allSettled()` returns both fulfilled and rejected result objects. Only fulfilled results have a `.value` property. Reading `.value` without first checking `status === 'fulfilled'` turns rejected results into `undefined`, which can silently drop failures.
+
+This rule reports direct `.map()` extraction from known `Promise.allSettled()` result arrays, including simple `const` aliases. It intentionally keeps a narrow inference boundary: arbitrary aliasing, mutable `let` tracking, custom guard functions without type information, and broad non-`.map()` dataflow are out of scope.
+
+With TypeScript type information, typed predicate filters that narrow entries to `PromiseFulfilledResult<T>` are treated as safe.
+
+## Examples
+
+```js
+// ❌
+const values = (await Promise.allSettled(promises)).map(result => result.value);
+
+// ✅
+const values = (await Promise.allSettled(promises))
+	.filter(result => result.status === 'fulfilled')
+	.map(result => result.value);
+```
+
+```js
+// ❌
+const values = Promise.allSettled(promises).then(results => results.map(result => result.value));
+
+// ✅
+const values = Promise.allSettled(promises).then(results =>
+	results.map(result => result.status === 'fulfilled' ? result.value : undefined)
+);
+```
+
+```ts
+// ✅
+const isFulfilled = <T>(result: PromiseSettledResult<T>): result is PromiseFulfilledResult<T> => result.status === 'fulfilled';
+const values = results.filter(isFulfilled).map(result => result.value);
+```

readme.md

@@ -235,6 +235,7 @@ export default defineConfig([
 | [no-unreadable-object-destructuring](docs/rules/no-unreadable-object-destructuring.md)                     | Disallow unreadable object destructuring.                                                                                      | ✅ ☑️ |    |    |    |
 | [no-unsafe-buffer-conversion](docs/rules/no-unsafe-buffer-conversion.md)                                   | Prevent unsafe use of ArrayBuffer view `.buffer`.                                                                              | ✅ ☑️ |    | 💡 |    |
 | [no-unsafe-dom-html](docs/rules/no-unsafe-dom-html.md)                                                     | Disallow unsafe DOM HTML APIs.                                                                                                 |      |    |    |    |
+| [no-unsafe-promise-all-settled-values](docs/rules/no-unsafe-promise-all-settled-values.md)                 | Disallow reading `.value` from `Promise.allSettled()` results without a fulfilled status guard.                                | ✅ ☑️ |    |    |    |
 | [no-unsafe-property-key](docs/rules/no-unsafe-property-key.md)                                             | Disallow unsafe values as property keys.                                                                                       | ✅    |    |    |    |
 | [no-unsafe-string-replacement](docs/rules/no-unsafe-string-replacement.md)                                 | Disallow non-literal replacement values in `String#replace()` and `String#replaceAll()`.                                       | ✅    |    |    |    |
 | [no-unused-array-method-return](docs/rules/no-unused-array-method-return.md)                               | Disallow ignoring the return value of selected array methods.                                                                  | ✅ ☑️ |    |    |    |

rules/index.js

@@ -144,6 +144,7 @@ export {default as 'no-unreadable-new-expression'} from './no-unreadable-new-exp
 export {default as 'no-unreadable-object-destructuring'} from './no-unreadable-object-destructuring.js';
 export {default as 'no-unsafe-buffer-conversion'} from './no-unsafe-buffer-conversion.js';
 export {default as 'no-unsafe-dom-html'} from './no-unsafe-dom-html.js';
+export {default as 'no-unsafe-promise-all-settled-values'} from './no-unsafe-promise-all-settled-values.js';
 export {default as 'no-unsafe-property-key'} from './no-unsafe-property-key.js';
 export {default as 'no-unsafe-string-replacement'} from './no-unsafe-string-replacement.js';
 export {default as 'no-unused-array-method-return'} from './no-unused-array-method-return.js';