Defer formatting when only one error is returned

format.go

@@ -11,9 +11,13 @@ type ErrorFormatFunc func([]error) string
 
 // ListFormatFunc is a basic formatter that outputs the number of errors
 // that occurred along with a bullet point list of the errors.
+//
+// If only one error is within the errror slice,
+// the formatting should be deferred to the one and only error present
 func ListFormatFunc(es []error) string {
 	if len(es) == 1 {
-		return fmt.Sprintf("1 error occurred:\n\t* %s\n\n", es[0])
+		// Formatting should be deferred to the single error present
+		return es[0].Error()
 	}
 
 	points := make([]string, len(es))

format_test.go

@@ -6,19 +6,33 @@ import (
 )
 
 func TestListFormatFuncSingle(t *testing.T) {
-	expected := `1 error occurred:
-	* foo
-
-`
-
-	errors := []error{
-		errors.New("foo"),
-	}
-
-	actual := ListFormatFunc(errors)
-	if actual != expected {
-		t.Fatalf("bad: %#v", actual)
-	}
+	t.Run("Flat", func(t *testing.T) {
+		expected := `foo`
+
+		errors := []error{
+			errors.New("foo"),
+		}
+
+		actual := ListFormatFunc(errors)
+		if actual != expected {
+			t.Fatalf("bad: %#v", actual)
+		}
+	})
+
+	t.Run("Nested", func(t *testing.T) {
+		expected := `foo`
+
+		nestedErrors := &Error{
+			Errors: []error{
+				&Error{Errors: []error{errors.New("foo")}},
+			},
+		}
+
+		actual := ListFormatFunc(nestedErrors.Errors)
+		if actual != expected {
+			t.Fatalf("bad: %#v", actual)
+		}
+	})
 }
 
 func TestListFormatFuncMultiple(t *testing.T) {