feat: sharable config presets

.golangci.example.yml

@@ -1,6 +1,11 @@
 # This file contains all available configuration options
 # with their default values.
 
+# configuration presets to use, each can be:
+# - a file path beginning with '.', which will be resolved relative to this config file
+# - a go module path, which will be searched for .golangci.yaml, .golangci.json etc
+presets: []
+
 # options for analysis running
 run:
   # default concurrency is a available CPU number

go.mod

@@ -78,6 +78,7 @@ require (
 	github.com/stretchr/testify v1.7.0
 	github.com/tdakkota/asciicheck v0.0.0-20200416200610-e657995f937b
 	github.com/tetafro/godot v1.4.10
+	github.com/thepwagner/golangci-lint-yaml v0.0.1 // indirect
 	github.com/timakin/bodyclose v0.0.0-20200424151742-cb6215831a94
 	github.com/tomarrell/wrapcheck/v2 v2.3.0
 	github.com/tommy-muehle/go-mnd/v2 v2.4.0

pkg/config/config.go

@@ -1,7 +1,8 @@
 package config
 
 type Config struct {
-	Run Run
+	Run     Run
+	Presets []string
 
 	Output Output
 

pkg/config/reader.go

@@ -5,10 +5,12 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"github.com/mitchellh/go-homedir"
 	"github.com/spf13/viper"
+	"golang.org/x/tools/go/packages"
 
 	"github.com/golangci/golangci-lint/pkg/fsutils"
 	"github.com/golangci/golangci-lint/pkg/logutils"
@@ -43,25 +45,26 @@ func (r *FileReader) Read() error {
 		return fmt.Errorf("can't parse --config option: %s", err)
 	}
 
+	v := viper.New()
 	if configFile != "" {
-		viper.SetConfigFile(configFile)
+		v.SetConfigFile(configFile)
 	} else {
-		r.setupConfigFileSearch()
+		r.setupConfigFileSearch(v)
 	}
 
-	return r.parseConfig()
+	return r.parseConfig(v)
 }
 
-func (r *FileReader) parseConfig() error {
-	if err := viper.ReadInConfig(); err != nil {
+func (r *FileReader) parseConfig(v *viper.Viper) error {
+	if err := v.ReadInConfig(); err != nil {
 		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
 			return nil
 		}
 
 		return fmt.Errorf("can't read viper config: %s", err)
 	}
 
-	usedConfigFile := viper.ConfigFileUsed()
+	usedConfigFile := v.ConfigFileUsed()
 	if usedConfigFile == "" {
 		return nil
 	}
@@ -72,10 +75,14 @@ func (r *FileReader) parseConfig() error {
 	}
 	r.log.Infof("Used config file %s", usedConfigFile)
 
-	if err := viper.Unmarshal(r.cfg); err != nil {
+	if err := v.Unmarshal(r.cfg); err != nil {
 		return fmt.Errorf("can't unmarshal config by viper: %s", err)
 	}
 
+	if err := r.mergePresets(v); err != nil {
+		return fmt.Errorf("can't merge presets: %s", err)
+	}
+
 	if err := r.validateConfig(); err != nil {
 		return fmt.Errorf("can't validate config: %s", err)
 	}
@@ -128,6 +135,105 @@ func (r *FileReader) validateConfig() error {
 	return nil
 }
 
+func (r *FileReader) mergePresets(v *viper.Viper) error {
+	if len(r.cfg.Presets) == 0 {
+		return nil
+	}
+	presets, err := r.loadPresets(v)
+	if err != nil {
+		return err
+	}
+
+	// Merge via viper, with special handling for .linters.{en,dis}abled slice
+	mergedV := viper.New()
+	lintersEnabled := map[string]struct{}{}
+	lintersDisabled := map[string]struct{}{}
+	for _, cfg := range append(presets, v) {
+		if err := mergedV.MergeConfigMap(cfg.AllSettings()); err != nil {
+			return fmt.Errorf("can't merge config %q: %w", cfg.ConfigFileUsed(), err)
+		}
+
+		for _, l := range cfg.GetStringSlice("linters.enable") {
+			lintersEnabled[l] = struct{}{}
+			delete(lintersDisabled, l)
+		}
+		for _, l := range cfg.GetStringSlice("linters.disable") {
+			lintersDisabled[l] = struct{}{}
+			delete(lintersEnabled, l)
+		}
+	}
+
+	if err := mergedV.Unmarshal(r.cfg); err != nil {
+		return fmt.Errorf("can't unmarshal merged config: %w", err)
+	}
+
+	if len(lintersEnabled) > 0 {
+		r.cfg.Linters.Enable = make([]string, 0, len(lintersEnabled))
+		for l := range lintersEnabled {
+			r.cfg.Linters.Enable = append(r.cfg.Linters.Enable, l)
+		}
+		sort.Strings(r.cfg.Linters.Enable)
+	} else {
+		r.cfg.Linters.Enable = nil
+	}
+	if len(lintersDisabled) > 0 {
+		r.cfg.Linters.Disable = make([]string, 0, len(lintersDisabled))
+		for l := range lintersDisabled {
+			r.cfg.Linters.Disable = append(r.cfg.Linters.Disable, l)
+		}
+		sort.Strings(r.cfg.Linters.Disable)
+	} else {
+		r.cfg.Linters.Disable = nil
+	}
+
+	return nil
+}
+
+const configName = ".golangci"
+
+func (r *FileReader) loadPresets(v *viper.Viper) ([]*viper.Viper, error) {
+	cfgBase := filepath.Dir(v.ConfigFileUsed())
+	presets := make([]*viper.Viper, 0, len(r.cfg.Presets))
+	for _, preset := range r.cfg.Presets {
+		presetV := viper.New()
+		if strings.HasPrefix(preset, ".") {
+			cfgFile := filepath.Join(cfgBase, preset)
+			presetV.SetConfigFile(cfgFile)
+		} else {
+			modDir, err := findModDir(preset)
+			if err != nil {
+				return nil, err
+			}
+			presetV.AddConfigPath(modDir)
+			presetV.SetConfigName(configName)
+		}
+
+		if err := presetV.ReadInConfig(); err != nil {
+			return nil, fmt.Errorf("can't read preset config %q: %w", preset, err)
+		}
+		r.log.Infof("Read preset module config file %s", presetV.ConfigFileUsed())
+
+		presets = append(presets, presetV)
+	}
+	return presets, nil
+}
+
+func findModDir(mod string) (string, error) {
+	cfg := &packages.Config{Mode: packages.NeedFiles}
+	pkgs, err := packages.Load(cfg, mod)
+	if err != nil {
+		return "", fmt.Errorf("can't load preset module %q: %w", mod, err)
+	}
+	pkg := pkgs[0]
+	if len(pkg.Errors) > 0 {
+		return "", fmt.Errorf("can't load preset module package %q: %+v", mod, pkg.Errors)
+	}
+	if len(pkg.GoFiles) == 0 {
+		return "", fmt.Errorf("empty preset module package: add at least one .go file %s", mod)
+	}
+	return filepath.Dir(pkg.GoFiles[0]), nil
+}
+
 func getFirstPathArg() string {
 	args := os.Args
 
@@ -153,7 +259,7 @@ func getFirstPathArg() string {
 	return firstArg
 }
 
-func (r *FileReader) setupConfigFileSearch() {
+func (r *FileReader) setupConfigFileSearch(v *viper.Viper) {
 	firstArg := getFirstPathArg()
 	absStartPath, err := filepath.Abs(firstArg)
 	if err != nil {
@@ -189,9 +295,10 @@ func (r *FileReader) setupConfigFileSearch() {
 	}
 
 	r.log.Infof("Config search paths: %s", configSearchPaths)
-	viper.SetConfigName(".golangci")
+
+	v.SetConfigName(configName)
 	for _, p := range configSearchPaths {
-		viper.AddConfigPath(p)
+		v.AddConfigPath(p)
 	}
 }
 

pkg/config/reader_test.go

@@ -0,0 +1,73 @@
+package config
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/golangci/golangci-lint/pkg/logutils"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFileReader_Read(t *testing.T) {
+	cases := map[string]Config{
+		"preset_parent.yml": {
+			Linters: Linters{
+				EnableAll: true,
+				Fast:      true,
+				Enable:    []string{"deadcode", "errcheck", "gosimple"},
+			},
+		},
+		"preset_single.yml": {
+			Linters: Linters{
+				Fast:    true,
+				Enable:  []string{"errcheck", "gosimple", "govet"},
+				Disable: []string{"deadcode"},
+			},
+			Presets: []string{"./preset_parent.yml"},
+		},
+		"preset_double.yml": {
+			Linters: Linters{
+				Enable:  []string{"errcheck", "gosimple", "govet"},
+				Disable: []string{"deadcode"},
+			},
+			Output: Output{
+				PrintIssuedLine: true,
+			},
+			Presets: []string{"./preset_parent.yml", "./preset_single.yml"},
+		},
+		"preset_order.yml": {
+			Linters: Linters{
+				Fast:    true,
+				Disable: []string{"deadcode", "errcheck", "gosimple", "govet"},
+			},
+			Presets: []string{"./preset_parent.yml", "./preset_single.yml", "./disable_all.yml"},
+		},
+	}
+
+	for cfgFile, expected := range cases {
+		t.Run(cfgFile, func(t *testing.T) {
+			cfg := readConfig(t, cfgFile)
+			assert.Equal(t, expected, cfg)
+		})
+	}
+}
+
+func TestFileReader_Read_Module(t *testing.T) {
+	cfg := readConfig(t, "preset_module.yml")
+	assert.NotEmpty(t, cfg.Linters.Enable)
+}
+
+func readConfig(t *testing.T, fn string) Config {
+	var cfg, cmdCfg Config
+	cmdCfg.Run.Config = filepath.Join("..", "..", "test", "testdata", "configs", fn)
+	log := logutils.NewMockLog()
+	log.On("Infof", mock.Anything, mock.Anything).Maybe()
+
+	r := NewFileReader(&cfg, &cmdCfg, log)
+	err := r.Read()
+	require.NoError(t, err)
+	return cfg
+}

test/testdata/configs/disable_all.yml

@@ -0,0 +1,6 @@
+linters:
+  disable:
+    - deadcode
+    - errcheck
+    - gosimple
+    - govet

test/testdata/configs/preset_double.yml

@@ -0,0 +1,11 @@
+linters:
+  # overwrite the value in preset_single.yml
+  fast: false
+
+# add a new value
+output:
+  print-issued-lines: true
+
+presets:
+  - ./preset_parent.yml
+  - ./preset_single.yml

test/testdata/configs/preset_module.yml

@@ -0,0 +1,3 @@
+# TODO: host a preset in the golangci org?
+presets:
+ - github.com/thepwagner/golangci-lint-yaml

test/testdata/configs/preset_order.yml

@@ -0,0 +1,5 @@
+presets:
+ - ./preset_parent.yml
+ - ./preset_single.yml
+ # appears last, overwriting previously enabled checks
+ - ./disable_all.yml

test/testdata/configs/preset_parent.yml

@@ -0,0 +1,7 @@
+linters:
+   enable-all: true
+   fast: true
+   enable:
+      - deadcode
+      - errcheck
+      - gosimple

test/testdata/configs/preset_single.yml

@@ -0,0 +1,11 @@
+linters:
+  # overwrite a value in preset_parent.yml
+  enable-all: false
+  # enable and disable a linter
+  enable:
+    - govet
+  disable:
+    - deadcode
+
+presets:
+ - ./preset_parent.yml