Preserve output value when only when error is produced

hashicorp · Oct 19, 2016 · a907df9 · a907df9
1 parent 4ad7911
commit a907df9
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/append.go b/append.go
@@ -40,10 +40,12 @@ func AppendNonNil(err error, errs ...error) error {
 
 	errs = removeNils(errs)
 	// Preserve input value when no errors have occurred
+	// Preserve output value when only one error is produced
 	if len(errs) == 0 {
 		return err
+	} else if (err == nil) && len(errs) == 1 {
+		return errs[0]
 	}
-
 	return Append(err, errs...)
 }
 

diff --git a/append_test.go b/append_test.go
@@ -79,6 +79,11 @@ func TestAppendNonNil(t *testing.T) {
 	if result != err1 {
 		t.Fatalf("input error modified: %s", result.Error())
 	}
+	err1 = errors.New("foo")
+	result = AppendNonNil(nil, err1, nil, nil)
+	if result != err1 {
+		t.Fatalf("input error modified: %s", result.Error())
+	}
 }
 
 func TestAppendNonNilStruct(t *testing.T) {