From 8ae84df993f63d1255a9b40a614fcc79fea8ad68 Mon Sep 17 00:00:00 2001
From: gcanti <giulio.canti@gmail.com>
Date: Sun, 16 Oct 2022 08:33:31 +0200
Subject: [PATCH] SemigroupKind: fix combineKind signature

---
 .changeset/heavy-laws-clean.md   |  5 +++++
 docs/modules/SemigroupKind.ts.md |  8 ++++----
 dtslint/ts4.1/SemigroupKind.ts   | 18 ++++++++++++++++++
 src/SemigroupKind.ts             |  8 ++++----
 4 files changed, 31 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/heavy-laws-clean.md
 create mode 100644 dtslint/ts4.1/SemigroupKind.ts

diff --git a/.changeset/heavy-laws-clean.md b/.changeset/heavy-laws-clean.md
new file mode 100644
index 000000000..f2722570a
--- /dev/null
+++ b/.changeset/heavy-laws-clean.md
@@ -0,0 +1,5 @@
+---
+"@fp-ts/core": patch
+---
+
+SemigroupKind: fix combineKind signature
diff --git a/docs/modules/SemigroupKind.ts.md b/docs/modules/SemigroupKind.ts.md
index 011af942d..cfd34f22b 100644
--- a/docs/modules/SemigroupKind.ts.md
+++ b/docs/modules/SemigroupKind.ts.md
@@ -25,10 +25,10 @@ Added in v3.0.0
 
 ```ts
 export interface SemigroupKind<F extends TypeLambda> extends Functor<F> {
-  readonly combineKind: <S, R, O, E, A, B>(
-    first: Kind<F, S, R, O, E, A>,
-    second: Kind<F, S, R, O, E, A>
-  ) => Kind<F, S, R, O, E, A | B>
+  readonly combineKind: <S, R1, O1, E1, A, R2, O2, E2, B>(
+    first: Kind<F, S, R1, O1, E1, A>,
+    second: Kind<F, S, R2, O2, E2, B>
+  ) => Kind<F, S, R1 & R2, O1 | O2, E1 | E2, A | B>
 
   readonly combineKindMany: <S, R, O, E, A>(
     start: Kind<F, S, R, O, E, A>,
diff --git a/dtslint/ts4.1/SemigroupKind.ts b/dtslint/ts4.1/SemigroupKind.ts
new file mode 100644
index 000000000..f08768768
--- /dev/null
+++ b/dtslint/ts4.1/SemigroupKind.ts
@@ -0,0 +1,18 @@
+import * as semigroupKind from "@fp-ts/core/SemigroupKind"
+import type { TypeLambda } from "@fp-ts/core/HKT"
+
+export interface ReaderAsyncWriter<R, E, A> {
+  (r: R): () => Promise<[E, A]>
+}
+
+export interface ReaderAsyncWriterTypeLambda extends TypeLambda {
+  readonly type: ReaderAsyncWriter<this["In1"], this["Out2"], this["Out1"]>
+}
+
+declare const fa: ReaderAsyncWriter<{ a: string }, "a", string>
+declare const fb: ReaderAsyncWriter<{ b: number }, "b", number>
+
+export declare const SemigroupKind: semigroupKind.SemigroupKind<ReaderAsyncWriterTypeLambda>
+
+// $ExpectType ReaderAsyncWriter<{ a: string; } & { b: number; }, "a" | "b", string | number>
+SemigroupKind.combineKind(fa, fb)
diff --git a/src/SemigroupKind.ts b/src/SemigroupKind.ts
index 81970b664..09dd36649 100644
--- a/src/SemigroupKind.ts
+++ b/src/SemigroupKind.ts
@@ -9,10 +9,10 @@ import type { Kind, TypeLambda } from "@fp-ts/core/HKT"
  * @since 3.0.0
  */
 export interface SemigroupKind<F extends TypeLambda> extends Functor<F> {
-  readonly combineKind: <S, R, O, E, A, B>(
-    first: Kind<F, S, R, O, E, A>,
-    second: Kind<F, S, R, O, E, A>
-  ) => Kind<F, S, R, O, E, A | B>
+  readonly combineKind: <S, R1, O1, E1, A, R2, O2, E2, B>(
+    first: Kind<F, S, R1, O1, E1, A>,
+    second: Kind<F, S, R2, O2, E2, B>
+  ) => Kind<F, S, R1 & R2, O1 | O2, E1 | E2, A | B>
 
   readonly combineKindMany: <S, R, O, E, A>(
     start: Kind<F, S, R, O, E, A>,