Paths: Ensure it doesn't recurse into Map or Set's prototype pr…

…operties (#772)
sindresorhus · Nov 28, 2023 · 6759853 · 6759853
1 parent 7144aed
commit 6759853
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/source/paths.d.ts b/source/paths.d.ts
@@ -78,7 +78,7 @@ open('listB.1'); // TypeError. Because listB only has one element.
 @category Array
 */
 export type Paths<T> =
-	T extends NonRecursiveType
+	T extends NonRecursiveType | ReadonlyMap<unknown, unknown> | ReadonlySet<unknown>
 		? never
 		: IsAny<T> extends true
 			? never

diff --git a/test-d/paths.ts b/test-d/paths.ts
@@ -67,6 +67,24 @@ expectType<'a'>(record);
 declare const record2: Paths<Record<1, unknown>>;
 expectType<1 | '1'>(record2);
 
+declare const map: Paths<{foo?: {bar?: Map<string, number>}}>;
+expectType<'foo' | 'foo.bar'>(map);
+
+declare const map2: Paths<Map<string, number>>;
+expectType<never>(map2);
+
+declare const readonlyMap: Paths<{foo?: {bar?: ReadonlyMap<string, number>}}>;
+expectType<'foo' | 'foo.bar'>(readonlyMap);
+
+declare const set: Paths<{foo?: {bar?: Set<string>}}>;
+expectType<'foo' | 'foo.bar'>(set);
+
+declare const set2: Paths<Set<string>>;
+expectType<never>(set2);
+
+declare const readonlySet: Paths<{foo?: {bar?: ReadonlySet<string>}}>;
+expectType<'foo' | 'foo.bar'>(readonlySet);
+
 // Test for unknown length array
 declare const trailingSpreadTuple: Paths<[{a: string}, ...Array<{b: number}>]>;
 expectType<number | `${number}` | '0.a' | `${number}.b`>(trailingSpreadTuple);