Correct partition signature

lune-climate · Sep 7, 2024 · 2842549 · 2842549
1 parent 8019469
commit 2842549
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Showing 2 changed files with 17 additions and 6 deletions.
diff --git a/src/result.ts b/src/result.ts
@@ -545,7 +545,7 @@ export namespace Result {
     /**
      * Partitions a set of results, separating the `Ok` and `Err` values.
      */
-    export function partition<const T extends Result<any, any>[]>(results: T): [ResultOkTypes<T>, ResultErrTypes<T>] {
+    export function partition<T extends Result<any, any>[]>(results: T): [ResultOkTypes<T>, ResultErrTypes<T>] {
         return results.reduce(
             ([oks, errors], v) =>
                 v.isOk()

diff --git a/test/result.test.ts b/test/result.test.ts
@@ -48,7 +48,10 @@ test('andThen', () => {
     const result = new Ok('Ok') as Result<string, boolean>;
     const then = result.andThen(() => new Err('broke') as Result<boolean, string>);
     expect(then).toMatchResult(new Err('broke'));
-    function takesResult(result: Result<boolean, string | boolean>): void {}
+
+    function takesResult(result: Result<boolean, string | boolean>): void {
+    }
+
     takesResult(then);
 });
 
@@ -200,6 +203,7 @@ test('Result.wrap', () => {
     class CustomError {
         readonly message = 'hi';
     }
+
     const err = new CustomError();
 
     const b = Result.wrap<number, CustomError>(() => {
@@ -217,6 +221,7 @@ test('Result.wrapAsync', async () => {
     class CustomError {
         readonly message = 'hi';
     }
+
     const err = new CustomError();
 
     const b = await Result.wrapAsync<number, CustomError>(async () => {
@@ -239,29 +244,35 @@ test('Result.partition', async () => {
     const ok1 = new Ok(true);
     const err0 = Err(Symbol());
     const err1 = new Err(Error());
+    const result0 = Ok(3) as unknown as Result<number, symbol>;
+    const result1 = new Ok(true) as unknown as Result<boolean, Error>;
 
     const all0 = Result.partition([]);
     expect(all0).toEqual([[], []]);
-    eq<typeof all0, [[], []]>(true);
+    eq<typeof all0, [never[], never[]]>(true);
 
     const all1 = Result.partition([ok0, ok1, err0, err1]);
     expect(all1).toEqual([
         [ok0.value, ok1.value],
         [err0.error, err1.error],
     ]);
-    eq<typeof all1, [[number, boolean, never, never], [never, never, symbol, Error]]>(true);
+    eq<typeof all1, [(number | boolean)[], (symbol | Error)[]]>(true);
 
     const all2 = Result.partition([ok0, ok1]);
     expect(all2).toEqual([[ok0.value, ok1.value], []]);
-    eq<typeof all2, [[number, boolean], [never, never]]>(true);
+    eq<typeof all2, [(number | boolean)[], never[]]>(true);
 
     const all3 = Result.partition([err0, err1]);
     expect(all3).toEqual([[], [err0.error, err1.error]]);
-    eq<typeof all3, [[never, never], [symbol, Error]]>(true);
+    eq<typeof all3, [never[], (symbol | Error)[]]>(true);
 
     const all4 = Result.partition([1, 2, 3, 4].map((num) => Ok(num) as Result<number, Error>));
     expect(all4).toEqual([[1, 2, 3, 4], []]);
     eq<typeof all4, [number[], Error[]]>(true);
+
+    const all5 = Result.partition([result0, result1]);
+    expect(all5).toEqual([[(result0 as Ok<number>).value, (result1 as Ok<boolean>).value], []]);
+    eq<typeof all5, [(number | boolean)[], (symbol | Error)[]]>(true);
 });
 
 test('safeUnwrap', () => {