Make $array and $tuple readonly

kshramt · Dec 30, 2023 · 504d273 · 504d273
1 parent 41db141
commit 504d273
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Showing 2 changed files with 23 additions and 10 deletions.
diff --git a/src/index.spec.ts b/src/index.spec.ts
@@ -359,12 +359,14 @@ type NExpect<T extends false> = T;
   }
   {
     const validator = T.$tuple([T.$number(), T.$string()]);
-    type _ = Expect<Check<T.$infer<typeof validator>, [number, string]>>;
+    type _ = Expect<
+      Check<T.$infer<typeof validator>, readonly [number, string]>
+    >;
   }
   {
     const validator = T.$tuple([T.$number(), T.$string()], T.$boolean());
     type _ = Expect<
-      Check<T.$infer<typeof validator>, [number, string, ...boolean[]]>
+      Check<T.$infer<typeof validator>, readonly [number, string, ...boolean[]]>
     >;
   }
   {
@@ -377,7 +379,12 @@ type NExpect<T extends false> = T;
     type _ = Expect<
       Check<
         T.$infer<typeof validator>,
-        { a: null; b: undefined; c: boolean; d: null | [string[]] }
+        {
+          a: null;
+          b: undefined;
+          c: boolean;
+          d: null | readonly [readonly string[]];
+        }
       >
     >;
   }

diff --git a/src/index.ts b/src/index.ts
@@ -87,19 +87,25 @@ export const $typeGuard = <T>(
   };
 };
 
-export function $tuple<T extends unknown[]>(
-  validators: [...{ [K in keyof T]: TValidator<T[K]> }],
-): (value: unknown, path?: TRef<TPath>) => value is T;
+export function $tuple<TTuple extends unknown[]>(
+  validators: [...{ [K in keyof TTuple]: TValidator<TTuple[K]> }],
+): (value: unknown, path?: TRef<TPath>) => value is readonly [...TTuple];
 export function $tuple<TTuple extends unknown[], TRest>(
   validators: [...{ [K in keyof TTuple]: TValidator<TTuple[K]> }],
   rest: TValidator<TRest>,
-): (value: unknown, path?: TRef<TPath>) => value is [...TTuple, ...TRest[]];
+): (
+  value: unknown,
+  path?: TRef<TPath>,
+) => value is readonly [...TTuple, ...TRest[]];
 export function $tuple<TTuple extends unknown[], TRest>(
   validators: [...{ [K in keyof TTuple]: TValidator<TTuple[K]> }],
   rest?: TValidator<TRest>,
 ) {
   if (rest === undefined) {
-    return (value: unknown, path?: TRef<TPath>): value is TTuple => {
+    return (
+      value: unknown,
+      path?: TRef<TPath>,
+    ): value is readonly [...TTuple] => {
       if (!Array.isArray(value)) {
         if (path) {
           path.value = { not_array: value };
@@ -130,7 +136,7 @@ export function $tuple<TTuple extends unknown[], TRest>(
     return (
       value: unknown,
       path?: TRef<TPath>,
-    ): value is [...TTuple, ...TRest[]] => {
+    ): value is readonly [...TTuple, ...TRest[]] => {
       if (!Array.isArray(value)) {
         if (path) {
           path.value = { not_array: value };
@@ -192,7 +198,7 @@ export const $literal = <T extends TNarrowable>(val: T) => {
 };
 
 export const $array = <T>(validator: TValidator<T>) => {
-  return (value: unknown, path?: TRef<TPath>): value is T[] => {
+  return (value: unknown, path?: TRef<TPath>): value is readonly T[] => {
     if (!Array.isArray(value)) {
       if (path) {
         path.value = { not_array: value };