fix Result to consider waiting flag in equality (#357)

Co-authored-by: Tim Smart <hello@timsmart.co>

Author: 0xh3x

.changeset/bumpy-pears-push.md

@@ -0,0 +1,5 @@
+---
+"@effect-atom/atom": patch
+---
+
+fix Result to consider waiting flag in equality

packages/atom/src/Result.ts

@@ -84,7 +84,7 @@ const ResultProto = {
     return pipeArguments(this, arguments)
   },
   [Equal.symbol](this: Result<any, any>, that: Result<any, any>): boolean {
-    if (this._tag !== that._tag && this.waiting !== that.waiting) {
+    if (this._tag !== that._tag || this.waiting !== that.waiting) {
       return false
     }
     switch (this._tag) {

packages/atom/test/Atom.test.ts

@@ -1170,7 +1170,7 @@ describe("Atom", () => {
 
       // optimistic phase: the optimistic value is set, but the true value is not
       expect(r.get(atom)).toEqual(Result.success(0))
-      expect(r.get(optimisticAtom)).toEqual(Result.success(1))
+      expect(r.get(optimisticAtom)).toEqual(Result.success(1, { waiting: true }))
 
       latch.unsafeOpen()
       await Effect.runPromise(Effect.yieldNow())

packages/atom/test/Result.test.ts

@@ -1,5 +1,5 @@
 import * as _ from "@effect-atom/atom/Result"
-import { Cause } from "effect"
+import { Cause, Equal } from "effect"
 import { describe, expect, it } from "vitest"
 
 describe("Result", () => {
@@ -14,4 +14,14 @@ describe("Result", () => {
     expect(matcher(_.failure(Cause.empty))).toEqual("fail")
     expect(matcher(_.success(1))).toEqual(1)
   })
+
+  it("considers waiting flag in equality", () => {
+    const success = _.success("value")
+    const waiting = _.waiting(success)
+
+    expect(Equal.isEqual(success)).toBe(true)
+    expect(Equal.isEqual(waiting)).toBe(true)
+    expect(Equal.equals(success, waiting)).toBe(false)
+    expect((success as any)[Equal.symbol](waiting)).toBe(false)
+  })
 })