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

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

internal/config/config.go

@@ -104,12 +104,12 @@ func ParseConfigFile(args []string) string {
 			return configFile
 		}
 
-		if strings.HasSuffix(cliFlag, "-config.file") {
-			if len(os.Args) <= i+1 {
+		if cliFlag == "--config.file" || cliFlag == "-config.file" {
+			if len(args) <= i+1 {
 				return ""
 			}
 
-			return os.Args[i+1]
+			return args[i+1]
 		}
 	}
 

internal/config/config_test.go

@@ -0,0 +1,130 @@
+// 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 config_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/alecthomas/kingpin/v2"
+	"github.com/prometheus-community/windows_exporter/internal/config"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseConfigFile(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name string
+		args []string
+		want string
+	}{
+		{name: "absent"},
+		{name: "long joined", args: []string{"--config.file=test.yaml"}, want: "test.yaml"},
+		{name: "short joined", args: []string{"-config.file=test.yaml"}, want: "test.yaml"},
+		{name: "long separate", args: []string{"--config.file", "test.yaml"}, want: "test.yaml"},
+		{name: "short separate", args: []string{"-config.file", "test.yaml"}, want: "test.yaml"},
+		{name: "after other flags", args: []string{"--log.level=debug", "--config.file", "test.yaml"}, want: "test.yaml"},
+		{name: "missing value", args: []string{"--config.file"}},
+		{name: "empty value", args: []string{"--config.file="}},
+		{name: "unrelated suffix", args: []string{"--other-config.file", "test.yaml"}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			require.Equal(t, tc.want, config.ParseConfigFile(tc.args))
+		})
+	}
+}
+
+func TestNewConfigFileResolver(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name      string
+		contents  string
+		errorText string
+	}{
+		{name: "empty"},
+		{name: "valid", contents: "log:\n  level: debug\nweb:\n  listen-address: ['127.0.0.1:9182', '[::1]:9182']\n"},
+		{name: "unknown key", contents: "unknown: value", errorText: "configuration file validation error"},
+		{name: "unknown collector option", contents: "collector:\n  cpu:\n    unknown: true\n", errorText: "configuration file validation error"},
+		{name: "malformed YAML", contents: "log: [", errorText: "configuration file validation error"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			path := filepath.Join(t.TempDir(), "config.yaml")
+			require.NoError(t, os.WriteFile(path, []byte(tc.contents), 0o600))
+
+			resolver, err := config.NewConfigFileResolver(path)
+			if tc.errorText != "" {
+				require.ErrorContains(t, err, tc.errorText)
+
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotNil(t, resolver)
+		})
+	}
+
+	t.Run("missing file", func(t *testing.T) {
+		t.Parallel()
+		_, err := config.NewConfigFileResolver(filepath.Join(t.TempDir(), "missing.yaml"))
+		require.ErrorContains(t, err, "failed to open configuration file")
+	})
+}
+
+func TestParse(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name      string
+		extraArgs []string
+		want      string
+		errorText string
+	}{
+		{name: "config defaults", want: "debug"},
+		{name: "CLI overrides config", extraArgs: []string{"--log.level=error"}, want: "error"},
+		{name: "invalid CLI flag", extraArgs: []string{"--unknown"}, errorText: "failed to bind configuration"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			path := filepath.Join(t.TempDir(), "config.yaml")
+			require.NoError(t, os.WriteFile(path, []byte("log:\n  level: debug\n"), 0o600))
+
+			app := kingpin.New("test", "test")
+			app.Flag("config.file", "config").String()
+			level := app.Flag("log.level", "level").Default("info").String()
+
+			args := append([]string{"--config.file=" + path}, tc.extraArgs...)
+
+			err := config.Parse(app, args)
+			if tc.errorText != "" {
+				require.ErrorContains(t, err, tc.errorText)
+
+				return
+			}
+
+			require.NoError(t, err)
+			require.Equal(t, tc.want, *level)
+		})
+	}
+}