chore: neutral configuration loader

Author: ldez

pkg/config/base_loader.go

@@ -0,0 +1,228 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+
+	"github.com/go-viper/mapstructure/v2"
+	"github.com/mitchellh/go-homedir"
+	"github.com/spf13/viper"
+
+	"github.com/golangci/golangci-lint/pkg/exitcodes"
+	"github.com/golangci/golangci-lint/pkg/fsutils"
+	"github.com/golangci/golangci-lint/pkg/logutils"
+)
+
+type CFG interface {
+	IsInternalTest() bool
+	SetConfigDir(dir string)
+}
+
+type BaseLoader struct {
+	opts LoaderOptions
+
+	viper *viper.Viper
+
+	log logutils.Log
+
+	cfg  CFG
+	args []string
+}
+
+func NewBaseLoader(log logutils.Log, v *viper.Viper, opts LoaderOptions, cfg CFG, args []string) *BaseLoader {
+	return &BaseLoader{
+		opts:  opts,
+		viper: v,
+		log:   log,
+		cfg:   cfg,
+		args:  args,
+	}
+}
+
+func (l *BaseLoader) Load() error {
+	err := l.setConfigFile()
+	if err != nil {
+		return err
+	}
+
+	err = l.parseConfig()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (l *BaseLoader) setConfigFile() error {
+	configFile, err := l.evaluateOptions()
+	if err != nil {
+		if errors.Is(err, errConfigDisabled) {
+			return nil
+		}
+
+		return fmt.Errorf("can't parse --config option: %w", err)
+	}
+
+	if configFile != "" {
+		l.viper.SetConfigFile(configFile)
+
+		// Assume YAML if the file has no extension.
+		if filepath.Ext(configFile) == "" {
+			l.viper.SetConfigType("yaml")
+		}
+	} else {
+		l.setupConfigFileSearch()
+	}
+
+	return nil
+}
+
+func (l *BaseLoader) evaluateOptions() (string, error) {
+	if l.opts.NoConfig && l.opts.Config != "" {
+		return "", errors.New("can't combine option --config and --no-config")
+	}
+
+	if l.opts.NoConfig {
+		return "", errConfigDisabled
+	}
+
+	configFile, err := homedir.Expand(l.opts.Config)
+	if err != nil {
+		return "", errors.New("failed to expand configuration path")
+	}
+
+	return configFile, nil
+}
+
+func (l *BaseLoader) setupConfigFileSearch() {
+	l.viper.SetConfigName(".golangci")
+
+	configSearchPaths := l.getConfigSearchPaths()
+
+	l.log.Infof("Config search paths: %s", configSearchPaths)
+
+	for _, p := range configSearchPaths {
+		l.viper.AddConfigPath(p)
+	}
+}
+
+func (l *BaseLoader) getConfigSearchPaths() []string {
+	firstArg := "./..."
+	if len(l.args) > 0 {
+		firstArg = l.args[0]
+	}
+
+	absPath, err := filepath.Abs(firstArg)
+	if err != nil {
+		l.log.Warnf("Can't make abs path for %q: %s", firstArg, err)
+		absPath = filepath.Clean(firstArg)
+	}
+
+	// start from it
+	var currentDir string
+	if fsutils.IsDir(absPath) {
+		currentDir = absPath
+	} else {
+		currentDir = filepath.Dir(absPath)
+	}
+
+	// find all dirs from it up to the root
+	searchPaths := []string{"./"}
+
+	for {
+		searchPaths = append(searchPaths, currentDir)
+
+		parent := filepath.Dir(currentDir)
+		if currentDir == parent || parent == "" {
+			break
+		}
+
+		currentDir = parent
+	}
+
+	// find home directory for global config
+	if home, err := homedir.Dir(); err != nil {
+		l.log.Warnf("Can't get user's home directory: %v", err)
+	} else if !slices.Contains(searchPaths, home) {
+		searchPaths = append(searchPaths, home)
+	}
+
+	return searchPaths
+}
+
+func (l *BaseLoader) parseConfig() error {
+	if err := l.viper.ReadInConfig(); err != nil {
+		var configFileNotFoundError viper.ConfigFileNotFoundError
+		if errors.As(err, &configFileNotFoundError) {
+			// Load configuration from flags only.
+			err = l.viper.Unmarshal(l.cfg, customDecoderHook())
+			if err != nil {
+				return fmt.Errorf("can't unmarshal config by viper (flags): %w", err)
+			}
+
+			return nil
+		}
+
+		return fmt.Errorf("can't read viper config: %w", err)
+	}
+
+	err := l.setConfigDir()
+	if err != nil {
+		return err
+	}
+
+	// Load configuration from all sources (flags, file).
+	if err := l.viper.Unmarshal(l.cfg, customDecoderHook()); err != nil {
+		return fmt.Errorf("can't unmarshal config by viper (flags, file): %w", err)
+	}
+
+	if l.cfg.IsInternalTest() { // just for testing purposes: to detect config file usage
+		_, _ = fmt.Fprintln(logutils.StdOut, "test")
+		os.Exit(exitcodes.Success)
+	}
+
+	return nil
+}
+
+func (l *BaseLoader) setConfigDir() error {
+	usedConfigFile := l.viper.ConfigFileUsed()
+	if usedConfigFile == "" {
+		return nil
+	}
+
+	if usedConfigFile == os.Stdin.Name() {
+		usedConfigFile = ""
+		l.log.Infof("Reading config file stdin")
+	} else {
+		var err error
+		usedConfigFile, err = fsutils.ShortestRelPath(usedConfigFile, "")
+		if err != nil {
+			l.log.Warnf("Can't pretty print config file path: %v", err)
+		}
+
+		l.log.Infof("Used config file %s", usedConfigFile)
+	}
+
+	usedConfigDir, err := filepath.Abs(filepath.Dir(usedConfigFile))
+	if err != nil {
+		return errors.New("can't get config directory")
+	}
+
+	l.cfg.SetConfigDir(usedConfigDir)
+
+	return nil
+}
+
+func customDecoderHook() viper.DecoderConfigOption {
+	return viper.DecodeHook(mapstructure.ComposeDecodeHookFunc(
+		// Default hooks (https://github.com/spf13/viper/blob/518241257478c557633ab36e474dfcaeb9a3c623/viper.go#L135-L138).
+		mapstructure.StringToTimeDurationHookFunc(),
+		mapstructure.StringToSliceHookFunc(","),
+
+		// Needed for forbidigo, and output.formats.
+		mapstructure.TextUnmarshallerHookFunc(),
+	))
+}

pkg/config/config.go

@@ -46,10 +46,19 @@ func (c *Config) GetConfigDir() string {
 	return c.cfgDir
 }
 
+// SetConfigDir sets the path to directory that contains golangci-lint config file.
+func (c *Config) SetConfigDir(dir string) {
+	c.cfgDir = dir
+}
+
 func (c *Config) GetBasePath() string {
 	return c.basePath
 }
 
+func (c *Config) IsInternalTest() bool {
+	return c.InternalTest
+}
+
 func (c *Config) Validate() error {
 	validators := []func() error{
 		c.Run.Validate,