Relax primitive dependency warning in useDeepCompareEffect

src/useDeepCompareEffect.ts

@@ -1,20 +1,23 @@
-import { DependencyList, EffectCallback } from 'react';
-import useCustomCompareEffect from './useCustomCompareEffect';
-import isDeepEqual from './misc/isDeepEqual';
+import { DependencyList, EffectCallback } from "react";
+import useCustomCompareEffect from "./useCustomCompareEffect";
+import isDeepEqual from "./misc/isDeepEqual";
 
 const isPrimitive = (val: any) => val !== Object(val);
 
 const useDeepCompareEffect = (effect: EffectCallback, deps: DependencyList) => {
-  if (process.env.NODE_ENV !== 'production') {
+  if (process.env.NODE_ENV !== "production") {
     if (!(deps instanceof Array) || !deps.length) {
       console.warn(
-        '`useDeepCompareEffect` should not be used with no dependencies. Use React.useEffect instead.'
+        "`useDeepCompareEffect` should not be used with no dependencies. Use React.useEffect instead."
       );
     }
 
-    if (deps.every(isPrimitive)) {
+    const allPrimitive = deps.every(isPrimitive);
+    const hasSingleDep = deps.length === 1;
+
+    if (allPrimitive && !hasSingleDep) {
       console.warn(
-        '`useDeepCompareEffect` should not be used with dependencies that are all primitive values. Use React.useEffect instead.'
+        "`useDeepCompareEffect` should not be used with dependencies that are all primitive values. Use React.useEffect instead."
       );
     }
   }

tests/useDeepCompareEffect.test.ts

@@ -1,14 +1,14 @@
-import { renderHook } from '@testing-library/react-hooks';
-import { useDeepCompareEffect } from '../src';
-import { useEffect } from 'react';
+import { renderHook } from "@testing-library/react-hooks";
+import { useDeepCompareEffect } from "../src";
+import { useEffect } from "react";
 
 let options = { max: 10 };
 const mockEffectNormal = jest.fn();
 const mockEffectDeep = jest.fn();
 const mockEffectCleanup = jest.fn();
 const mockEffectCallback = jest.fn().mockReturnValue(mockEffectCleanup);
 
-it('should run provided object once', () => {
+it("should run provided object once", () => {
   const { rerender: rerenderNormal } = renderHook(() => useEffect(mockEffectNormal, [options]));
   const { rerender: rerenderDeep } = renderHook(() =>
     useDeepCompareEffect(mockEffectDeep, [options])
@@ -32,10 +32,24 @@ it('should run provided object once', () => {
   expect(mockEffectDeep).toHaveBeenCalledTimes(1);
 });
 
-it('should run clean-up provided on unmount', () => {
+it("should run clean-up provided on unmount", () => {
   const { unmount } = renderHook(() => useDeepCompareEffect(mockEffectCallback, [options]));
   expect(mockEffectCleanup).not.toHaveBeenCalled();
 
   unmount();
   expect(mockEffectCleanup).toHaveBeenCalledTimes(1);
 });
+
+it("does not warn when a single primitive dependency is used", () => {
+  const warnSpy = jest.spyOn(console, "warn").mockImplementation(() => {});
+
+  const effect = jest.fn();
+
+  renderHook(() => useDeepCompareEffect(effect, [undefined]));
+
+  expect(warnSpy).not.toHaveBeenCalledWith(
+    "`useDeepCompareEffect` should not be used with dependencies that are all primitive values. Use React.useEffect instead."
+  );
+
+  warnSpy.mockRestore();
+});