revert: changes to isObject (#472)

README.md

@@ -13,41 +13,44 @@ Function documentation available [here](https://alcalzone.github.io/shared-utils
 <!--
 	Placeholder for the next version (at the beginning of the line):
 	### __WORK IN PROGRESS__
--->
+-->
+### __WORK IN PROGRESS__
+Undo changes to `isObject` from `4.0.6`. TS narrowing in 4.8.2 is broken.
+
 ### 4.0.6 (2022-09-07)
-* Fix: correctly narrow return type of `isObject`
-
+* Fix: correctly narrow return type of `isObject`
+
 ### 4.0.5 (2022-09-07)
-* Fix: correctly narrow return type of isArray for `{}` arguments
-
+* Fix: correctly narrow return type of isArray for `{}` arguments
+
 ### 4.0.4 (2022-09-07)
-* Fix: narrowed type for `isArray` is inferred correctly for `readonly` arrays
-
+* Fix: narrowed type for `isArray` is inferred correctly for `readonly` arrays
+
 ### 4.0.3 (2022-08-27)
-* Update `isArray` to be compatible with TS 4.8 changes
-
+* Update `isArray` to be compatible with TS 4.8 changes
+
 ### 4.0.1 (2021-11-15)
-`SortedQueue`: Fixed an issue where inserting an item before the first one would cause the queue to lose track of items
-
+`SortedQueue`: Fixed an issue where inserting an item before the first one would cause the queue to lose track of items
+
 ### 4.0.0 (2021-06-19)
-* Node.js 12+ is now required
-
+* Node.js 12+ is now required
+
 ### 3.0.4 (2021-04-24)
 * Fix compatibility of `wait()` with Electron if `unref` is `true`
-* Dependency updates
-
+* Dependency updates
+
 ### 3.0.3 (2021-03-09)
 #### Fixes
-* Fixed compatibility with TypeScript 4.2
-
+* Fixed compatibility with TypeScript 4.2
+
 ### 3.0.2 (2021-01-16)
 #### Fixes
-* The argument to `resolve` of `DeferredPromise` is no longer optional, except for `Promise<void>`
-
+* The argument to `resolve` of `DeferredPromise` is no longer optional, except for `Promise<void>`
+
 ### 3.0.1 (2020-12-05)
 #### Fixes
-* The typeguard `isObject` no longer narrows the type of the argument to `object`
-
+* The typeguard `isObject` no longer narrows the type of the argument to `object`
+
 ### 3.0.0 (2020-08-16)
 #### Breaking changes
 * Renamed the following types:
@@ -72,7 +75,7 @@ Function documentation available [here](https://alcalzone.github.io/shared-utils
 
 #### Fixes
 * The type `CallbackAPIReturnType` now works with `strictNullChecks`.
-* The type `Promisify` is no longer experimental and no longer messes up the inferred signature argument names
-
+* The type `Promisify` is no longer experimental and no longer messes up the inferred signature argument names
+
 ### 2.3.0 (2020-06-08)
 * Added optional `unref` parameter to `async` -> `wait(ms, [unref])`

src/sorted-list/sorted-list.test.ts

@@ -251,7 +251,7 @@ describe("sorted-list => ", () => {
 		expect(list[list.length]).to.be.undefined;
 	});
 
-	it.only("adding and removing should not break the doubly linked list", () => {
+	it("adding and removing should not break the doubly linked list", () => {
 		const list = new SortedList<number>();
 		list.add(2);
 		list.add(1);

src/typeguards/index.ts

@@ -1,14 +1,8 @@
-type ExtractObject<T> =
-	T extends readonly unknown[] ? never
-	: {} extends T ? Record<string | number | symbol, unknown>
-	: T extends Record<string | number | symbol, unknown> ? T
-	: never;
-
 /**
  * Tests whether the given variable is a real object and not an Array
  * @param it The variable to test
  */
-export function isObject<T>(it: T): it is T & ExtractObject<T> {
+export function isObject<T>(it: T): it is T & Record<string, unknown> {
 	// This is necessary because:
 	// typeof null === 'object'
 	// typeof [] === 'object'

src/typeguards/typeguards.test.ts

@@ -7,7 +7,9 @@ import type { Equals } from "../types";
 function assertTrue<T extends true>() {
 	return undefined!;
 }
-type UnspecifiedObject = Record<string | number | symbol, unknown>;
+function assertFalse<T extends false>() {
+	return undefined!;
+}
 
 describe("lib/typeguards =>", () => {
 	describe("isObject() => ", () => {
@@ -35,79 +37,6 @@ describe("lib/typeguards =>", () => {
 			const foo = { a: { b: "c" } } as unknown;
 			isObject(foo) && isObject(foo.a) && isObject(foo.a.b);
 		});
-
-		it("inferred types are correct", () => {
-			const _any = undefined as any;
-			const _unknown = undefined as unknown;
-			const _unknownArray = _unknown as unknown[];
-			const _number = _unknown as number;
-			const _numberArray = _unknown as number[];
-			const _readonlyNumberArray = _unknown as readonly number[];
-			const _nonNullish = _unknown as {};
-			const _specificObjectNullable = _unknown as
-				| { a: number }
-				| undefined;
-			const _objectOrArray = _unknown as { a: number } | string[];
-
-			if (isObject(_any)) {
-				assertTrue<Equals<typeof _any, any>>();
-				_any;
-				// ^?
-			}
-
-			if (isObject(_unknown)) {
-				assertTrue<Equals<typeof _unknown, UnspecifiedObject>>();
-				_unknown;
-				// ^?
-			}
-
-			if (isObject(_unknownArray)) {
-				assertTrue<Equals<typeof _unknownArray, never>>();
-				_unknownArray;
-				// ^?
-			}
-
-			if (isObject(_number)) {
-				assertTrue<Equals<typeof _number, never>>();
-				_number;
-				// ^?
-			}
-
-			if (isObject(_numberArray)) {
-				assertTrue<Equals<typeof _numberArray, never>>();
-				_numberArray;
-				// ^?
-			}
-
-			if (isObject(_readonlyNumberArray)) {
-				assertTrue<Equals<typeof _readonlyNumberArray, never>>();
-				_readonlyNumberArray;
-				// ^?
-			}
-
-			if (isObject(_nonNullish)) {
-				assertTrue<Equals<typeof _nonNullish, UnspecifiedObject>>();
-				_nonNullish;
-				// ^?
-			}
-
-			if (isObject(_specificObjectNullable)) {
-				assertTrue<
-					Equals<
-						typeof _specificObjectNullable,
-						NonNullable<typeof _specificObjectNullable>
-					>
-				>();
-				_specificObjectNullable;
-				// ^?
-			}
-
-			if (isObject(_objectOrArray)) {
-				assertTrue<Equals<typeof _objectOrArray, { a: number }>>();
-				_objectOrArray;
-				// ^?
-			}
-		});
 	});
 
 	describe("isArray() => ", () => {