Add apFirstW and apSecondW to ReaderTask (#1958)

Author: DenisFrezzato

docs/modules/ReaderTask.ts.md

@@ -105,7 +105,9 @@ Added in v2.3.0
   - [ApT](#apt)
   - [ap](#ap)
   - [apFirst](#apfirst)
+  - [apFirstW](#apfirstw)
   - [apSecond](#apsecond)
+  - [apSecondW](#apsecondw)
   - [apW](#apw)
   - [local](#local)
 - [zone of death](#zone-of-death)
@@ -1191,6 +1193,22 @@ export declare const apFirst: <E, B>(second: ReaderTask<E, B>) => <A>(first: Rea
 
 Added in v2.3.0
 
+## apFirstW
+
+Less strict version of [`apFirst`](#apfirst).
+
+The `W` suffix (short for **W**idening) means that the environment types will be merged.
+
+**Signature**
+
+```ts
+export declare const apFirstW: <R2, B>(
+  second: ReaderTask<R2, B>
+) => <R1, A>(first: ReaderTask<R1, A>) => ReaderTask<R1 & R2, A>
+```
+
+Added in v2.17.0
+
 ## apSecond
 
 Combine two effectful actions, keeping only the result of the second.
@@ -1203,6 +1221,22 @@ export declare const apSecond: <E, B>(second: ReaderTask<E, B>) => <A>(first: Re
 
 Added in v2.3.0
 
+## apSecondW
+
+Less strict version of [`apSecond`](#apsecond).
+
+The `W` suffix (short for **W**idening) means that the environment types will be merged.
+
+**Signature**
+
+```ts
+export declare const apSecondW: <R2, B>(
+  second: ReaderTask<R2, B>
+) => <R1, A>(first: ReaderTask<R1, A>) => ReaderTask<R1 & R2, B>
+```
+
+Added in v2.17.0
+
 ## apW
 
 Less strict version of [`ap`](#ap).

src/ReaderTask.ts

@@ -252,13 +252,35 @@ export const ApplyPar: Apply2<URI> = {
  */
 export const apFirst = /*#__PURE__*/ apFirst_(ApplyPar)
 
+/**
+ * Less strict version of [`apFirst`](#apfirst).
+ *
+ * The `W` suffix (short for **W**idening) means that the environment types will be merged.
+ *
+ * @since 2.17.0
+ */
+export const apFirstW: <R2, B>(
+  second: ReaderTask<R2, B>
+) => <R1, A>(first: ReaderTask<R1, A>) => ReaderTask<R1 & R2, A> = apFirst as any
+
 /**
  * Combine two effectful actions, keeping only the result of the second.
  *
  * @since 2.3.0
  */
 export const apSecond = /*#__PURE__*/ apSecond_(ApplyPar)
 
+/**
+ * Less strict version of [`apSecond`](#apsecond).
+ *
+ * The `W` suffix (short for **W**idening) means that the environment types will be merged.
+ *
+ * @since 2.17.0
+ */
+export const apSecondW: <R2, B>(
+  second: ReaderTask<R2, B>
+) => <R1, A>(first: ReaderTask<R1, A>) => ReaderTask<R1 & R2, B> = apSecond as any
+
 /**
  * Runs computations in parallel.
  *

test/ReaderTask.ts

@@ -28,10 +28,22 @@ describe('ReaderTask', () => {
     U.deepStrictEqual(await pipe(_.of('a'), _.apFirst(_.of('b')))({})(), 'a')
   })
 
+  it('apFirstW', async () => {
+    const fa = _.of<{ readonly k: string }, string>('a')
+    const fb = _.of<{ readonly x: number }, boolean>(true)
+    U.deepStrictEqual(await pipe(fa, _.apFirstW(fb))({ k: 'v', x: 42 })(), 'a')
+  })
+
   it('apSecond', async () => {
     U.deepStrictEqual(await pipe(_.of('a'), _.apSecond(_.of('b')))({})(), 'b')
   })
 
+  it('apSecondW', async () => {
+    const fa = _.of<{ readonly k: string }, string>('a')
+    const fb = _.of<{ readonly x: number }, boolean>(true)
+    U.deepStrictEqual(await pipe(fa, _.apSecondW(fb))({ k: 'v', x: 42 })(), true)
+  })
+
   it('flatMap', async () => {
     const f = (a: string) => _.of(a.length)
     U.deepStrictEqual(await pipe(_.of('foo'), _.flatMap(f))({})(), 3)