Tweak combining APIs

Author: eikemeier

.buildkite/pipeline.yaml

@@ -4,19 +4,14 @@ steps:
     commands:
       - golangci-lint run --timeout 10m0s
 
-  - label: ':hammer: Test'
+  - label: ':hammer: Test (:codecov: + :codeclimate:)'
     commands:
-      - gotestsum --junitfile test.xml ./...
+      - gotestsum --junitfile test.xml -- -race -coverprofile=cover.out ./...
+      - sh .buildkite/upload_coverage.sh cover.out
     plugins:
-      - test-collector#v1.10.0:
+      - test-collector#v1.10.1:
           files: test.xml
           format: junit
     env:
       GOEXPERIMENT: rangefunc
 
-  - label: ':codecov: + :codeclimate: Coverage'
-    commands:
-      - go test -race -coverprofile=cover.out ./...
-      - sh .buildkite/upload_coverage.sh cover.out
-    env:
-      GOEXPERIMENT: rangefunc

.codeclimate.yml

@@ -13,3 +13,6 @@ exclude_patterns:
   - "go.sum"
   - "LICENSE"
   - "nocopy.go"
+engines:
+  golangci:
+    enabled: true

.github/workflows/test.yml

@@ -26,7 +26,7 @@ jobs:
       - name: 🧸 golangci-lint
         uses: golangci/golangci-lint-action@v4
         with:
-          version: v1.56.1
+          version: v1.56.2
       - name: 🔨 Test
         run: go test -race ./...
         env:

README.md

@@ -7,6 +7,7 @@
 [![Maintainability](https://api.codeclimate.com/v1/badges/12a77c18122e2d1e1f6b/maintainability)](https://codeclimate.com/github/fillmore-labs/promise/maintainability)
 [![Go Report Card](https://goreportcard.com/badge/fillmore-labs.com/promise)](https://goreportcard.com/report/fillmore-labs.com/promise)
 [![License](https://img.shields.io/github/license/fillmore-labs/promise)](https://www.apache.org/licenses/LICENSE-2.0)
+[![FOSSA Status](https://app.fossa.com/api/projects/git%2Bgithub.com%2Ffillmore-labs%2Fpromise.svg?type=shield&issueType=license)](https://app.fossa.com/projects/git%2Bgithub.com%2Ffillmore-labs%2Fpromise?ref=badge_shield&issueType=license)
 
 The `promise` package provides interfaces and utilities for writing asynchronous code in Go.
 

combine.go

@@ -19,28 +19,48 @@ package promise
 import (
 	"context"
 	"fmt"
-	"runtime/trace"
+	"reflect"
 
 	"fillmore-labs.com/promise/result"
 )
 
-// List is a list of [Future], representing results of asynchronous tasks.
-type List[R any] []Future[R]
+// AnyFuture matches a [Future] of any type.
+type AnyFuture interface {
+	reflect() reflect.Value
+}
+
+// AwaitAll returns a function that yields the results of all futures.
+// If the context is canceled, it returns an error for the remaining futures.
+func AwaitAll[R any](ctx context.Context, futures ...Future[R]) func(yield func(int, result.Result[R]) bool) {
+	i := newIterator(ctx, convertValue[R], futures)
 
-// All returns a function that yields the results of all futures.
+	return i.yieldTo
+}
+
+// AwaitAllAny returns a function that yields the results of all futures.
 // If the context is canceled, it returns an error for the remaining futures.
-func (l List[R]) All(ctx context.Context) func(yield func(int, result.Result[R]) bool) {
-	defer trace.StartRegion(ctx, "asyncSeq").End()
-	s := newIterator(ctx, l)
+func AwaitAllAny(ctx context.Context, futures ...AnyFuture) func(yield func(int, result.Result[any]) bool) {
+	i := newIterator(ctx, convertValueAny, futures)
+
+	return i.yieldTo
+}
 
-	return s.yieldTo
+// AwaitAllResults waits for all futures to complete and returns the results.
+// If the context is canceled, it returns early with errors for the remaining futures.
+func AwaitAllResults[R any](ctx context.Context, futures ...Future[R]) []result.Result[R] {
+	return awaitAllResults(len(futures), AwaitAll(ctx, futures...))
 }
 
-// AwaitAll waits for all futures to complete and returns the results.
+// AwaitAllResultsAny waits for all futures to complete and returns the results.
 // If the context is canceled, it returns early with errors for the remaining futures.
-func (l List[R]) AwaitAll(ctx context.Context) []result.Result[R] {
-	results := make([]result.Result[R], len(l))
-	l.All(ctx)(func(i int, r result.Result[R]) bool {
+func AwaitAllResultsAny(ctx context.Context, futures ...AnyFuture) []result.Result[any] {
+	return awaitAllResults(len(futures), AwaitAllAny(ctx, futures...))
+}
+
+func awaitAllResults[R any](n int, iter func(yield func(int, result.Result[R]) bool)) []result.Result[R] {
+	results := make([]result.Result[R], n)
+
+	iter(func(i int, r result.Result[R]) bool {
 		results[i] = r
 
 		return true
@@ -51,10 +71,21 @@ func (l List[R]) AwaitAll(ctx context.Context) []result.Result[R] {
 
 // AwaitAllValues returns the values of completed futures.
 // If any future fails or the context is canceled, it returns early with an error.
-func (l List[R]) AwaitAllValues(ctx context.Context) ([]R, error) {
-	results := make([]R, len(l))
+func AwaitAllValues[R any](ctx context.Context, futures ...Future[R]) ([]R, error) {
+	return awaitAllValues(len(futures), AwaitAll(ctx, futures...))
+}
+
+// AwaitAllValuesAny returns the values of completed futures.
+// If any future fails or the context is canceled, it returns early with an error.
+func AwaitAllValuesAny(ctx context.Context, futures ...AnyFuture) ([]any, error) {
+	return awaitAllValues(len(futures), AwaitAllAny(ctx, futures...))
+}
+
+func awaitAllValues[R any](n int, iter func(yield func(int, result.Result[R]) bool)) ([]R, error) {
+	results := make([]R, n)
 	var yieldErr error
-	l.All(ctx)(func(i int, r result.Result[R]) bool {
+
+	iter(func(i int, r result.Result[R]) bool {
 		if r.Err() != nil {
 			yieldErr = fmt.Errorf("list AwaitAllValues result %d: %w", i, r.Err())
 
@@ -70,13 +101,25 @@ func (l List[R]) AwaitAllValues(ctx context.Context) ([]R, error) {
 
 // AwaitFirst returns the result of the first completed future.
 // If the context is canceled, it returns early with an error.
-func (l List[R]) AwaitFirst(ctx context.Context) (R, error) {
+func AwaitFirst[R any](ctx context.Context, futures ...Future[R]) (R, error) {
+	return awaitFirst(AwaitAll(ctx, futures...))
+}
+
+// AwaitFirstAny returns the result of the first completed future.
+// If the context is canceled, it returns early with an error.
+func AwaitFirstAny(ctx context.Context, futures ...AnyFuture) (any, error) {
+	return awaitFirst(AwaitAllAny(ctx, futures...))
+}
+
+func awaitFirst[R any](iter func(yield func(int, result.Result[R]) bool)) (R, error) {
 	var v result.Result[R]
-	l.All(ctx)(func(_ int, r result.Result[R]) bool {
+
+	iter(func(_ int, r result.Result[R]) bool {
 		v = r
 
 		return false
 	})
+
 	if v == nil {
 		return *new(R), ErrNoResult
 	}

combine_all_test.go

@@ -42,16 +42,15 @@ func TestAll(t *testing.T) {
 	}
 
 	for i, v := range values {
-		value, err := v.value, v.err
-		go promises[i].Do(func() (int, error) { return value, err })
+		promises[i].Do(func() (int, error) { return v.value, v.err })
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
 	// when
-	var results [3]result.Result[int]
-	for i, r := range futures.All(ctx) { //nolint:typecheck
+	results := make([]result.Result[int], len(futures))
+	for i, r := range promise.AwaitAll(ctx, futures...) { //nolint:typecheck
 		results[i] = r
 	}
 
@@ -74,13 +73,50 @@ func TestAllEmpty(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	var futures promise.List[int]
-
 	// when
-	allFutures := futures.All(ctx)
+	allFutures := promise.AwaitAllResults[int](ctx)
 
 	// then
+	assert.Zero(t, len(allFutures))
 	for _, v := range allFutures { //nolint:typecheck
 		t.Errorf("Invalid value %v", v)
 	}
 }
+
+func TestAnyAll(t *testing.T) {
+	t.Parallel()
+
+	// given
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	p1, f1 := promise.New[int]()
+	p2, f2 := promise.New[string]()
+	p3, f3 := promise.New[struct{}]()
+
+	p1.Resolve(1)
+	p2.Resolve("test")
+	p3.Resolve(struct{}{})
+
+	// when
+	results := make([]result.Result[any], 3)
+	for i, r := range promise.AwaitAllAny(ctx, f1, f2, f3) { //nolint:typecheck
+		results[i] = r
+	}
+
+	// then
+	for i, r := range results {
+		if assert.NoError(t, r.Err()) {
+			switch i {
+			case 0:
+				assert.Equal(t, 1, r.Value())
+			case 1:
+				assert.Equal(t, "test", r.Value())
+			case 2:
+				assert.Equal(t, struct{}{}, r.Value())
+			default:
+				assert.Fail(t, "unexpected index")
+			}
+		}
+	}
+}