From 1aed347a125ed3847ec90863424810d6759cbc85 Mon Sep 17 00:00:00 2001
From: Giulio Canti <giulio.canti@gmail.com>
Date: Mon, 10 Jun 2024 16:02:35 +0200
Subject: [PATCH] =?UTF-8?q?Updated=20`Chunk.toArray`=20and=20`Chunk.toRead?=
 =?UTF-8?q?onlyArray`.=20Improved=20functio=E2=80=A6=20(#2970)?=
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---
 .changeset/lucky-seahorses-obey.md |  5 +++++
 packages/effect/dtslint/Chunk.ts   | 20 +++++++++++++++++++
 packages/effect/src/Chunk.ts       | 31 +++++++++++++++++++++---------
 3 files changed, 47 insertions(+), 9 deletions(-)
 create mode 100644 .changeset/lucky-seahorses-obey.md

diff --git a/.changeset/lucky-seahorses-obey.md b/.changeset/lucky-seahorses-obey.md
new file mode 100644
index 0000000000..d5a6efc64e
--- /dev/null
+++ b/.changeset/lucky-seahorses-obey.md
@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+Updated `Chunk.toArray` and `Chunk.toReadonlyArray`. Improved function signatures to preserve non-empty status of chunks during conversion.
diff --git a/packages/effect/dtslint/Chunk.ts b/packages/effect/dtslint/Chunk.ts
index 27b8bafaec..60648e1dee 100644
--- a/packages/effect/dtslint/Chunk.ts
+++ b/packages/effect/dtslint/Chunk.ts
@@ -487,3 +487,23 @@ Chunk.reverse(nonEmptyNumbers)
 
 // $ExpectType NonEmptyChunk<number>
 pipe(nonEmptyNumbers, Chunk.reverse)
+
+// -------------------------------------------------------------------------------------
+// toArray
+// -------------------------------------------------------------------------------------
+
+// $ExpectType string[]
+Chunk.toArray(hole<Chunk.Chunk<string>>())
+
+// $ExpectType [string, ...string[]]
+Chunk.toArray(hole<Chunk.NonEmptyChunk<string>>())
+
+// -------------------------------------------------------------------------------------
+// toArray
+// -------------------------------------------------------------------------------------
+
+// $ExpectType readonly string[]
+Chunk.toReadonlyArray(hole<Chunk.Chunk<string>>())
+
+// $ExpectType readonly [string, ...string[]]
+Chunk.toReadonlyArray(hole<Chunk.NonEmptyChunk<string>>())
diff --git a/packages/effect/src/Chunk.ts b/packages/effect/src/Chunk.ts
index e043723851..4e3aa3cb32 100644
--- a/packages/effect/src/Chunk.ts
+++ b/packages/effect/src/Chunk.ts
@@ -279,21 +279,21 @@ const copyToArray = <A>(self: Chunk<A>, array: Array<any>, initial: number): voi
   }
 }
 
-/**
- * Converts the specified `Chunk` to a `Array`.
- *
- * @category conversions
- * @since 2.0.0
- */
-export const toArray = <A>(self: Chunk<A>): Array<A> => toReadonlyArray(self).slice()
+const toArray_ = <A>(self: Chunk<A>): Array<A> => toReadonlyArray(self).slice()
 
 /**
- * Converts the specified `Chunk` to a `ReadonlyArray`.
+ * Converts a `Chunk` into an `Array`. If the provided `Chunk` is non-empty
+ * (`NonEmptyChunk`), the function will return a `NonEmptyArray`, ensuring the
+ * non-empty property is preserved.
  *
  * @category conversions
  * @since 2.0.0
  */
-export const toReadonlyArray = <A>(self: Chunk<A>): ReadonlyArray<A> => {
+export const toArray: <S extends Chunk<any>>(
+  self: S
+) => S extends NonEmptyChunk<any> ? RA.NonEmptyArray<Chunk.Infer<S>> : Array<Chunk.Infer<S>> = toArray_ as any
+
+const toReadonlyArray_ = <A>(self: Chunk<A>): ReadonlyArray<A> => {
   switch (self.backing._tag) {
     case "IEmpty": {
       return emptyArray
@@ -316,6 +316,19 @@ export const toReadonlyArray = <A>(self: Chunk<A>): ReadonlyArray<A> => {
   }
 }
 
+/**
+ * Converts a `Chunk` into a `ReadonlyArray`. If the provided `Chunk` is
+ * non-empty (`NonEmptyChunk`), the function will return a
+ * `NonEmptyReadonlyArray`, ensuring the non-empty property is preserved.
+ *
+ * @category conversions
+ * @since 2.0.0
+ */
+export const toReadonlyArray: <S extends Chunk<any>>(
+  self: S
+) => S extends NonEmptyChunk<any> ? RA.NonEmptyReadonlyArray<Chunk.Infer<S>> : ReadonlyArray<Chunk.Infer<S>> =
+  toReadonlyArray_ as any
+
 const reverseChunk = <A>(self: Chunk<A>): Chunk<A> => {
   switch (self.backing._tag) {
     case "IEmpty":