actor/test: extend TestAwaitFuture to cover fn.Err result path
What the developer wrote
Authored by Olaoluwa Osuntokun
actor/test: extend TestAwaitFuture to cover fn.Err result path
In this commit, we extend TestAwaitFuture to cover the case where the
future is completed with an fn.Err result. The existing test only
exercised the fn.Ok (success) and context cancellation paths.
The new case calls promise.Complete(fn.Err[string](sentinel)) directly
and verifies that AwaitFuture surfaces the error as the second return
value while returning the zero string value in the first, which is the
documented contract for Result[T].Unpack().
What changed, and why it matters
This commit only adds a new test case to an existing unit test. It checks that a helper function correctly returns an error when a future/promise is completed with an error value. There are no changes to production code, no bug fixes, and no security-relevant behavior changes.
No action needed. This is a benign test-only change.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The change extends TestAwaitFuture in actor/future_test.go to cover the fn.Err result path of AwaitFuture. It adds a test scenario where a Promise[string] is completed with fn.Errstring, and asserts that AwaitFuture returns the zero string value and the sentinel error. This is purely a test-coverage improvement; no implementation code was modified.
Changed components
actor/future_test.goInspect captured patch +12 / −1
diff --git a/actor/future_test.go b/actor/future_test.go
index 45d6314..519f0d4 100644
--- a/actor/future_test.go
+++ b/actor/future_test.go
@@ -458,7 +458,8 @@ func TestCompleteWith(t *testing.T) {
}
// TestAwaitFuture verifies that AwaitFuture unpacks a resolved future into a
-// (value, nil) pair and that context cancellation before resolution is
+// (value, nil) pair, that a future completed with fn.Err is reported as a
+// (zero, err) pair, and that context cancellation before resolution is
// reported as a (zero, ctx.Err()) pair.
func TestAwaitFuture(t *testing.T) {
t.Parallel()
@@ -471,6 +472,16 @@ func TestAwaitFuture(t *testing.T) {
require.NoError(t, err)
require.Equal(t, "hello", val)
+ // Future completed with fn.Err — should surface the error as the
+ // second return value with the zero string value.
+ sentinel := fmt.Errorf("result-level error")
+ errPromise := NewPromise[string]()
+ errPromise.Complete(fn.Err[string](sentinel))
+
+ val3, err3 := AwaitFuture(context.Background(), errPromise.Future())
+ require.ErrorIs(t, err3, sentinel)
+ require.Equal(t, "", val3, "zero value expected on fn.Err result")
+
// Cancelled context — should return the zero value and ctx.Err().
unresolved := NewPromise[string]()
ctx, cancel := context.WithCancel(context.Background())
Why this scored 15/100
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