fix(useAsyncIterState): disallow user manipulation of the state iterable's current value property (#43)

Author: shtaif

eslint.config.mjs

@@ -43,6 +43,7 @@ export default [
       ['@typescript-eslint/no-explicit-any']: 'off',
       ['@typescript-eslint/no-non-null-assertion']: 'off',
       ['@typescript-eslint/no-empty-function']: 'off',
+      ['@typescript-eslint/no-this-alias']: 'off',
       ['@typescript-eslint/no-unused-expressions']: 'warn',
       ['@typescript-eslint/no-unused-vars']: [
         'warn',

spec/tests/useAsyncIterState.spec.tsx

@@ -153,4 +153,12 @@ describe('`useAsyncIterState` hook', () => {
       expect(currentValues).toStrictEqual([undefined, 'a', 'b', 'c']);
     }
   );
+
+  it(gray("The state iterable's `.current.value` property is read-only"), async () => {
+    const [values] = renderHook(() => useAsyncIterState<number>()).result.current;
+
+    expect(() => {
+      (values.value as any).current = "can't do this...";
+    }).toThrow(TypeError);
+  });
 });

src/useAsyncIterState/IterableChannel.ts

@@ -6,10 +6,11 @@ export { IterableChannel, type AsyncIterableSubject };
 class IterableChannel<T> {
   #isClosed = false;
   #nextIteration = promiseWithResolvers<IteratorResult<T, void>>();
+  #currentValue: T | undefined;
 
   put(value: T): void {
     if (!this.#isClosed) {
-      this.values.value.current = value;
+      this.#currentValue = value;
       this.#nextIteration.resolve({ done: false, value });
       this.#nextIteration = promiseWithResolvers();
     }
@@ -21,9 +22,14 @@ class IterableChannel<T> {
   }
 
   values: AsyncIterableSubject<T> = {
-    value: {
-      current: undefined,
-    },
+    value: (() => {
+      const self = this;
+      return {
+        get current() {
+          return self.#currentValue;
+        },
+      };
+    })(),
 
     [Symbol.asyncIterator]: () => {
       const whenIteratorClosed = promiseWithResolvers<IteratorReturnResult<undefined>>();
@@ -52,7 +58,7 @@ type AsyncIterableSubject<T> = {
   /**
    * A React Ref-like object whose inner `current` property shows the most up to date state value.
    */
-  value: MutableRefObject<T | undefined>;
+  value: Readonly<MutableRefObject<T | undefined>>;
 
   /**
    * Returns an async iterator to iterate over. All iterators returned by this share the same source