2 files changed, 96 insertions, 0 deletions
diff --git a/pkg/coroutine/coroutine.go b/pkg/coroutine/coroutine.go
new file mode 100644
index 0000000..96d149e
--- /dev/null
+++ b/pkg/coroutine/coroutine.go
@@ -0,0 +1,33 @@
+package coroutine
+
+import (
+	"context"
+)
+
+// WrapProcess wraps process into a go routine and make it cancelable through context
+func WrapProcess[V any](ctx context.Context, fun func() (V, error)) (V, error) {
+	c := make(chan V)
+	e := make(chan error)
+	go func() {
+		defer close(c)
+		defer close(e)
+
+		v, err := fun()
+		if err != nil {
+			e <- err
+		} else {
+			c <- v
+		}
+	}()
+
+	select {
+	case <-ctx.Done():
+		var zero V
+		return zero, ctx.Err()
+	case m := <-c:
+		return m, nil
+	case err := <-e:
+		var zero V
+		return zero, err
+	}
+}
diff --git a/pkg/coroutine/coroutine_test.go b/pkg/coroutine/coroutine_test.go
new file mode 100644
index 0000000..e876ec3
--- /dev/null
+++ b/pkg/coroutine/coroutine_test.go
@@ -0,0 +1,63 @@
+//go:build unit
+
+package coroutine
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"testing"
+	"time"
+
+	"git.sr.ht/~gabrielgio/img/pkg/testkit"
+)
+
+var rError = errors.New("This is a error")
+
+func imediatReturn() (string, error) {
+	return "A string", nil
+}
+
+func imediatErrorReturn() (string, error) {
+	return "", rError
+}
+
+func haltedReturn() (string, error) {
+	time.Sleep(time.Hour)
+	return "", nil
+}
+
+func TestImediatReturn(t *testing.T) {
+	ctx := context.Background()
+	v, err := WrapProcess(ctx, imediatReturn)
+	testkit.TestError(t, "WrapProcess", nil, err)
+	testkit.TestValue(t, "WrapProcess", "A string", v)
+}
+
+func TestImediatErrorReturn(t *testing.T) {
+	ctx := context.Background()
+	v, err := WrapProcess(ctx, imediatErrorReturn)
+	testkit.TestError(t, "WrapProcess", rError, err)
+	testkit.TestValue(t, "WrapProcess", "", v)
+}
+
+func TestHaltedReturn(t *testing.T) {
+	ctx := context.Background()
+	ctx, cancel := context.WithCancel(ctx)
+
+	var (
+		err error
+		wg  sync.WaitGroup
+	)
+
+	wg.Add(1)
+	go func(err *error) {
+		defer wg.Done()
+		_, *err = WrapProcess(ctx, haltedReturn)
+	}(&err)
+
+	cancel()
+	wg.Wait()
+
+	testkit.TestError(t, "WrapProcess", context.Canceled, err)
+}