chore: consolidate CI and expand Windows test coverage (#2498)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

internal/utils/testutils/testutils_test.go

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+
+package testutils
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/prometheus-community/windows_exporter/internal/pdh"
+	"github.com/prometheus-community/windows_exporter/internal/types"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNoDataOnly(t *testing.T) {
+	t.Parallel()
+
+	failure := errors.New("collector failed")
+	for _, tc := range []struct {
+		name string
+		err  error
+		want bool
+	}{
+		{name: "nil"},
+		{name: "PDH no data", err: pdh.ErrNoData, want: true},
+		{name: "collector no data", err: types.ErrNoData, want: true},
+		{name: "wrapped", err: fmt.Errorf("empty instances: %w", pdh.ErrNoData), want: true},
+		{name: "joined empty groups", err: errors.Join(pdh.ErrNoData, types.ErrNoData), want: true},
+		{name: "failure", err: failure},
+		{name: "mixed failures", err: errors.Join(pdh.ErrNoData, failure)},
+		{name: "nested mixed failures", err: fmt.Errorf("child: %w", errors.Join(pdh.ErrNoData, failure))},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			require.Equal(t, tc.want, noDataOnly(tc.err))
+		})
+	}
+}