add failing test for #100

tests/issue_100.spec.ts

@@ -0,0 +1,44 @@
+import { describe, expect, it } from 'vitest';
+import { memoize } from 'proxy-memoize';
+
+describe('#100', () => {
+  it('should select correctly', () => {
+    type State = {
+      book1: {
+        staticProp: string;
+        priceString: string;
+      };
+    };
+
+    const state1: State = {
+      book1: {
+        staticProp: '5',
+        priceString: '10',
+      },
+    };
+
+    const state2: State = {
+      book1: {
+        staticProp: '5',
+        priceString: '20',
+      },
+    };
+
+    const selectAllBooks = memoize((state: State) => Object.values(state));
+
+    const selectPriceString = memoize(
+      (state: State) => state.book1.priceString,
+    );
+
+    const selectAdjustedPriceString = memoize((state: State) => {
+      const priceString = selectPriceString(state);
+      state.book1.staticProp; // touch the prop
+      return priceString;
+    });
+
+    selectAllBooks(state1);
+
+    expect(selectAdjustedPriceString(state1)).toBe('10');
+    expect(selectAdjustedPriceString(state2)).toBe('20');
+  });
+});