From f6db09e65ae9658d08f90be9e7f2cb0410bf0b47 Mon Sep 17 00:00:00 2001
From: Giulio Canti <giulio.canti@gmail.com>
Date: Fri, 8 Mar 2024 10:42:35 +0100
Subject: [PATCH] =?UTF-8?q?Either:=20fix=20`getEquivalence`=20parameter=20?=
 =?UTF-8?q?order=20from=20`Either.getEquivale=E2=80=A6=20(#2243)?=
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---
 .changeset/strong-falcons-exercise.md |  5 +++++
 packages/effect/src/Either.ts         | 12 ++++++------
 packages/effect/test/Either.test.ts   |  2 +-
 packages/schema/src/Schema.ts         |  2 +-
 4 files changed, 13 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/strong-falcons-exercise.md

diff --git a/.changeset/strong-falcons-exercise.md b/.changeset/strong-falcons-exercise.md
new file mode 100644
index 0000000000..4e2e3688b6
--- /dev/null
+++ b/.changeset/strong-falcons-exercise.md
@@ -0,0 +1,5 @@
+---
+"effect": minor
+---
+
+Either: fix `getEquivalence` parameter order from `Either.getEquivalence(left, right)` to `Either.getEquivalence({ left, right })`
diff --git a/packages/effect/src/Either.ts b/packages/effect/src/Either.ts
index ba37261459..13974f6159 100644
--- a/packages/effect/src/Either.ts
+++ b/packages/effect/src/Either.ts
@@ -287,15 +287,15 @@ export const getLeft: <R, L>(self: Either<R, L>) => Option<L> = either.getLeft
  * @category equivalence
  * @since 2.0.0
  */
-export const getEquivalence = <R, L>(
-  EquivalenceL: Equivalence.Equivalence<L>,
-  EquivalenceR: Equivalence.Equivalence<R>
-): Equivalence.Equivalence<Either<R, L>> =>
+export const getEquivalence = <R, L>({ left, right }: {
+  right: Equivalence.Equivalence<R>
+  left: Equivalence.Equivalence<L>
+}): Equivalence.Equivalence<Either<R, L>> =>
   Equivalence.make((x, y) =>
     x === y ||
     (isLeft(x) ?
-      isLeft(y) && EquivalenceL(x.left, y.left) :
-      isRight(y) && EquivalenceR(x.right, y.right))
+      isLeft(y) && left(x.left, y.left) :
+      isRight(y) && right(x.right, y.right))
   )
 
 /**
diff --git a/packages/effect/test/Either.test.ts b/packages/effect/test/Either.test.ts
index f8448f0239..158b492114 100644
--- a/packages/effect/test/Either.test.ts
+++ b/packages/effect/test/Either.test.ts
@@ -177,7 +177,7 @@ describe("Either", () => {
   })
 
   it("getEquivalence", () => {
-    const isEquivalent = Either.getEquivalence(S.Equivalence, N.Equivalence)
+    const isEquivalent = Either.getEquivalence({ right: N.Equivalence, left: S.Equivalence })
     Util.deepStrictEqual(isEquivalent(Either.right(1), Either.right(1)), true)
     Util.deepStrictEqual(isEquivalent(Either.right(1), Either.right(2)), false)
     Util.deepStrictEqual(isEquivalent(Either.right(1), Either.left("foo")), false)
diff --git a/packages/schema/src/Schema.ts b/packages/schema/src/Schema.ts
index a71c2fd103..3cc21caf45 100644
--- a/packages/schema/src/Schema.ts
+++ b/packages/schema/src/Schema.ts
@@ -5315,7 +5315,7 @@ export const eitherFromSelf = <R extends Schema.Any, L extends Schema.Any>({ lef
       description: `Either<${format(right)}, ${format(left)}>`,
       pretty: eitherPretty,
       arbitrary: eitherArbitrary,
-      equivalence: (right, left) => Either.getEquivalence(left, right)
+      equivalence: (right, left) => Either.getEquivalence({ left, right })
     }
   )
 }