feat: add getContext.

Author: ghosind

all.go

@@ -35,9 +35,7 @@ func all(parent context.Context, funcs ...AsyncFn) (int, error) {
 		return -1, nil
 	}
 
-	if parent == nil {
-		parent = context.Background()
-	}
+	parent = getContext(parent)
 
 	ctx, canFunc := context.WithCancel(parent)
 	defer canFunc()
@@ -114,9 +112,7 @@ func allCompleted(
 		return
 	}
 
-	if parent == nil {
-		parent = context.Background()
-	}
+	parent = getContext(parent)
 
 	wg := sync.WaitGroup{}
 	wg.Add(len(funcs))

async.go

@@ -15,3 +15,13 @@ type executeResult struct {
 	// Index is the index of the function in the parameters list.
 	Index int
 }
+
+// getContext returns the specified non-nil context from the parameter, or creates and returns a
+// new empty context.
+func getContext(ctx context.Context) context.Context {
+	if ctx != nil {
+		return ctx
+	}
+
+	return context.Background()
+}

async_test.go

@@ -0,0 +1,21 @@
+package async
+
+import (
+	"context"
+	"testing"
+
+	"github.com/ghosind/go-assert"
+)
+
+func TestGetContext(t *testing.T) {
+	a := assert.New(t)
+
+	todoCtx := context.TODO()
+	ctx := getContext(todoCtx)
+	a.EqualNow(ctx, todoCtx)
+
+	//lint:ignore SA1012 for test case only
+	ctx = getContext(nil)
+	a.NotNilNow(ctx)
+	a.NotEqualNow(ctx, todoCtx)
+}

race.go

@@ -28,9 +28,7 @@ func race(ctx context.Context, funcs ...AsyncFn) (int, error) {
 		return -1, nil
 	}
 
-	if ctx == nil {
-		ctx = context.Background()
-	}
+	ctx = getContext(ctx)
 
 	finished := atomic.Bool{}
 	ch := make(chan executeResult)