From aa6f07920e5fae874e536e69f5e725c571a40fba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Valverd=C3=A9?= <julien.valverde@mailo.com>
Date: Wed, 26 Aug 2026 00:21:06 +0200
Subject: [PATCH] Fix Mutation

---
 packages/effect-view/src/Mutation.test.ts | 23 +++++++++++++++++++++++
 packages/effect-view/src/Mutation.ts      | 20 +++++++++++---------
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/packages/effect-view/src/Mutation.test.ts b/packages/effect-view/src/Mutation.test.ts
index ad714e2..5e84e86 100644
--- a/packages/effect-view/src/Mutation.test.ts
+++ b/packages/effect-view/src/Mutation.test.ts
@@ -77,6 +77,29 @@ describe("Mutation", () => {
             expect(result.result.previousSuccess.value.value).toBe("saved")
     })
 
+    it("runs a second mutation with its own key, not the previous one", async () => {
+        const result = await runMutationTest(Effect.gen(function*() {
+            const calls: Array<string> = []
+            const mutation = yield* Mutation.make({
+                f: (key: string) => Effect.sync(() => {
+                    calls.push(key)
+                    return key
+                }),
+            })
+
+            const first = yield* mutation.mutate("a")
+            const second = yield* mutation.mutate("b")
+
+            return { calls, first, second }
+        }))
+
+        expect(result.calls).toEqual(["a", "b"])
+        expect(result.first.key.value).toBe("a")
+        expect(expectSuccessValue(result.first)).toBe("a")
+        expect(result.second.key.value).toBe("b")
+        expect(expectSuccessValue(result.second)).toBe("b")
+    })
+
     it("mutateView returns a waiting state without waiting for completion", async () => {
         const result = await runMutationTest(Effect.gen(function*() {
             const deferred = yield* Deferred.make<string>()
diff --git a/packages/effect-view/src/Mutation.ts b/packages/effect-view/src/Mutation.ts
index 073630d..18c8766 100644
--- a/packages/effect-view/src/Mutation.ts
+++ b/packages/effect-view/src/Mutation.ts
@@ -78,8 +78,10 @@ extends Pipeable.Class implements Mutation<K, A, E, R> {
         Scope.Scope | R
     > {
         return Effect.gen({ self: this }, function*() {
+            const currentKey = Option.some(key) as Option.Some<K>
+
             const previous: MutationState<K, A, E> = Option.getOrElse(yield* Lens.get(this.latestFinalState), () => ({
-                key: Option.some(key) as Option.Some<K>,
+                key: currentKey,
                 result: AsyncResult.initial(),
             }))
             const state = yield* makeMutationStateLens(previous)
@@ -89,17 +91,17 @@ extends Pipeable.Class implements Mutation<K, A, E, R> {
                     state,
                     previous => AsyncResult.match(previous.result, {
                         onInitial: () => ({
-                            key: previous.key,
+                            key: currentKey,
                             result: AsyncResult.initial(true),
                         }),
                         onSuccess: result => ({
-                            key: previous.key,
+                            key: currentKey,
                             result: AsyncResult.success(result.value, {
                                 waiting: true,
                             }),
                         }),
                         onFailure: result => ({
-                            key: previous.key,
+                            key: currentKey,
                             result: AsyncResult.failure(result.cause, {
                                 waiting: true,
                                 previousSuccess: result.previousSuccess,
@@ -108,7 +110,7 @@ extends Pipeable.Class implements Mutation<K, A, E, R> {
                     }
                 )),
 
-                Effect.onExit(this.f(previous.key.value), exit => Effect.gen({ self: this }, function*() {
+                Effect.onExit(this.f(key), exit => Effect.gen({ self: this }, function*() {
                     const fiberId = yield* Effect.fiberId
                     const fiber = yield* Lens.get(this.fiber)
 
@@ -119,24 +121,24 @@ extends Pipeable.Class implements Mutation<K, A, E, R> {
                         state,
                         previous => Exit.match(exit, {
                             onSuccess: v => ({
-                                key: previous.key,
+                                key: currentKey,
                                 result: AsyncResult.success(v),
                             }),
                             onFailure: c => Cause.hasInterruptsOnly(c)
                                 ? previous
                                 : AsyncResult.match(previous.result, {
                                     onInitial: () => ({
-                                        key: previous.key,
+                                        key: currentKey,
                                         result: AsyncResult.failure(c),
                                     }),
                                     onSuccess: v => ({
-                                        key: previous.key,
+                                        key: currentKey,
                                         result: AsyncResult.failure(c, {
                                             previousSuccess: Option.some(v),
                                         }),
                                     }),
                                     onFailure: v => ({
-                                        key: previous.key,
+                                        key: currentKey,
                                         result: AsyncResult.failure(c, {
                                             previousSuccess: v.previousSuccess,
                                         }),