feat: foreach preserve non emptyness. (#2608)

Co-authored-by: Tim <hello@timsmart.co>
Effect-TS · Apr 25, 2024 · 868ed2a · 868ed2a
1 parent 6222404
commit 868ed2a
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Showing 4 changed files with 125 additions and 13 deletions.
diff --git a/.changeset/fair-adults-chew.md b/.changeset/fair-adults-chew.md
@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+feat: foreach preserve non emptyness.
diff --git a/packages/effect/dtslint/Effect.ts b/packages/effect/dtslint/Effect.ts
@@ -1,3 +1,4 @@
+import type { NonEmptyReadonlyArray } from "effect/Array"
 import type { Cause } from "effect/Cause"
 import * as Effect from "effect/Effect"
 import { pipe } from "effect/Function"
@@ -15,19 +16,19 @@ declare const numberArray: Array<number>
 declare const numberEffectIterable: Array<Effect.Effect<number>>
 
 // -------------------------------------------------------------------------------------
-// forEach
+// forEach - array
 // -------------------------------------------------------------------------------------
 
 // $ExpectType Effect<string[], "err-1", "dep-1">
-Effect.forEach(["a", "b"], (
+Effect.forEach(["a", "b"] as Array<string>, (
   // $ExpectType string
   _a,
   // $ExpectType number
   _i
 ) => string)
 
 // $ExpectType Effect<void, "err-1", "dep-1">
-Effect.forEach(["a", "b"], (
+Effect.forEach(["a", "b"] as Array<string>, (
   // $ExpectType string
   _a,
   // $ExpectType number
@@ -56,6 +57,90 @@ pipe(
   ) => string, { discard: true })
 )
 
+// -------------------------------------------------------------------------------------
+// forEach - nonempty
+// -------------------------------------------------------------------------------------
+
+// $ExpectType Effect<[string, ...string[]], "err-1", "dep-1">
+Effect.forEach(["a", "b"], (
+  // $ExpectType string
+  _a,
+  // $ExpectType number
+  _i
+) => string)
+
+// $ExpectType Effect<void, "err-1", "dep-1">
+Effect.forEach(["a", "b"], (
+  // $ExpectType string
+  _a,
+  // $ExpectType number
+  _i
+) => string, { discard: true })
+
+// $ExpectType Effect<[string, ...string[]], "err-1", "dep-1">
+pipe(
+  ["a", "b"] as NonEmptyReadonlyArray<string>,
+  Effect.forEach((
+    // $ExpectType string
+    _a,
+    // $ExpectType number
+    _i
+  ) => string)
+)
+
+// $ExpectType Effect<void, "err-1", "dep-1">
+pipe(
+  ["a", "b"] as NonEmptyReadonlyArray<string>,
+  Effect.forEach((
+    // $ExpectType string
+    _a,
+    // $ExpectType number
+    _i
+  ) => string, { discard: true })
+)
+
+// -------------------------------------------------------------------------------------
+// forEach - tuple as non empty array
+// -------------------------------------------------------------------------------------
+
+// $ExpectType Effect<[string, ...string[]], "err-1", "dep-1">
+Effect.forEach(["a", "b"] as const, (
+  // $ExpectType "a" | "b"
+  _a,
+  // $ExpectType number
+  _i
+) => string)
+
+// $ExpectType Effect<void, "err-1", "dep-1">
+Effect.forEach(["a", "b"] as const, (
+  // $ExpectType "a" | "b"
+  _a,
+  // $ExpectType number
+  _i
+) => string, { discard: true })
+
+// $ExpectType Effect<[string, ...string[]], "err-1", "dep-1">
+pipe(
+  ["a", "b"] as const,
+  Effect.forEach((
+    // $ExpectType "a" | "b"
+    _a,
+    // $ExpectType number
+    _i
+  ) => string)
+)
+
+// $ExpectType Effect<void, "err-1", "dep-1">
+pipe(
+  ["a", "b"] as const,
+  Effect.forEach((
+    // $ExpectType "a" | "b"
+    _a,
+    // $ExpectType number
+    _i
+  ) => string, { discard: true })
+)
+
 // -------------------------------------------------------------------------------------
 // all - tuple
 // -------------------------------------------------------------------------------------

diff --git a/packages/effect/src/Effect.ts b/packages/effect/src/Effect.ts
@@ -1,6 +1,7 @@
 /**
  * @since 2.0.0
  */
+import type * as RA from "./Array.js"
 import type * as Cause from "./Cause.js"
 import type * as Chunk from "./Chunk.js"
 import type * as Clock from "./Clock.js"
@@ -648,20 +649,21 @@ export const findFirst: {
 export const firstSuccessOf: <Eff extends Effect<any, any, any>>(
   effects: Iterable<Eff>
 ) => Effect<Effect.Success<Eff>, Effect.Error<Eff>, Effect.Context<Eff>> = effect.firstSuccessOf
-
 /**
  * @since 2.0.0
  * @category collecting & elements
  */
 export const forEach: {
-  <A, B, E, R>(
-    f: (a: A, i: number) => Effect<B, E, R>,
+  <B, E, R, S extends Iterable<any>>(
+    f: (a: RA.ReadonlyArray.Infer<S>, i: number) => Effect<B, E, R>,
     options?: {
       readonly concurrency?: Concurrency | undefined
       readonly batching?: boolean | "inherit" | undefined
       readonly discard?: false | undefined
     } | undefined
-  ): (self: Iterable<A>) => Effect<Array<B>, E, R>
+  ): (
+    self: S
+  ) => Effect<RA.ReadonlyArray.With<S, B>, E, R>
   <A, B, E, R>(
     f: (a: A, i: number) => Effect<B, E, R>,
     options: {
@@ -670,6 +672,15 @@ export const forEach: {
       readonly discard: true
     }
   ): (self: Iterable<A>) => Effect<void, E, R>
+  <A, B, E, R>(
+    self: RA.NonEmptyReadonlyArray<A>,
+    f: (a: A, i: number) => Effect<B, E, R>,
+    options?: {
+      readonly concurrency?: Concurrency | undefined
+      readonly batching?: boolean | "inherit" | undefined
+      readonly discard?: false | undefined
+    } | undefined
+  ): Effect<RA.NonEmptyArray<B>, E, R>
   <A, B, E, R>(
     self: Iterable<A>,
     f: (a: A, i: number) => Effect<B, E, R>,
@@ -688,7 +699,7 @@ export const forEach: {
       readonly discard: true
     }
   ): Effect<void, E, R>
-} = fiberRuntime.forEach
+} = fiberRuntime.forEach as any
 
 /**
  * Returns a successful effect with the head of the collection if the collection

diff --git a/packages/effect/src/internal/fiberRuntime.ts b/packages/effect/src/internal/fiberRuntime.ts
@@ -1883,14 +1883,16 @@ export const replicateEffect: {
 
 /* @internal */
 export const forEach: {
-  <A, B, E, R>(
-    f: (a: A, i: number) => Effect.Effect<B, E, R>,
+  <B, E, R, S extends Iterable<any>>(
+    f: (a: RA.ReadonlyArray.Infer<S>, i: number) => Effect.Effect<B, E, R>,
     options?: {
       readonly concurrency?: Concurrency | undefined
       readonly batching?: boolean | "inherit" | undefined
       readonly discard?: false | undefined
-    }
-  ): (self: Iterable<A>) => Effect.Effect<Array<B>, E, R>
+    } | undefined
+  ): (
+    self: S
+  ) => Effect.Effect<RA.ReadonlyArray.With<S, B>, E, R>
   <A, B, E, R>(
     f: (a: A, i: number) => Effect.Effect<B, E, R>,
     options: {
@@ -1899,14 +1901,23 @@ export const forEach: {
       readonly discard: true
     }
   ): (self: Iterable<A>) => Effect.Effect<void, E, R>
+  <A, B, E, R>(
+    self: RA.NonEmptyReadonlyArray<A>,
+    f: (a: A, i: number) => Effect.Effect<B, E, R>,
+    options?: {
+      readonly concurrency?: Concurrency | undefined
+      readonly batching?: boolean | "inherit" | undefined
+      readonly discard?: false | undefined
+    } | undefined
+  ): Effect.Effect<RA.NonEmptyArray<B>, E, R>
   <A, B, E, R>(
     self: Iterable<A>,
     f: (a: A, i: number) => Effect.Effect<B, E, R>,
     options?: {
       readonly concurrency?: Concurrency | undefined
       readonly batching?: boolean | "inherit" | undefined
       readonly discard?: false | undefined
-    }
+    } | undefined
   ): Effect.Effect<Array<B>, E, R>
   <A, B, E, R>(
     self: Iterable<A>,