Add "revive" linter (#1729)

Author: sspaink

.golangci.example.yml

@@ -350,6 +350,13 @@ linters-settings:
   rowserrcheck:
     packages:
       - github.com/jmoiron/sqlx
+  revive:
+    # see https://github.com/mgechev/revive#available-rules for details.
+    ignore-generated-header: true
+    severity: warning
+    rules:
+      - name: indent-error-flow
+        severity: warning
   testpackage:
     # regexp pattern to skip files
     skip-regexp: (export|internal)_test\.go

.golangci.yml

@@ -117,6 +117,7 @@ linters:
   # - nestif
   # - prealloc
   # - testpackage
+  # - revive
   # - wsl
 
 issues:

go.mod

@@ -39,6 +39,8 @@ require (
 	github.com/matoous/godox v0.0.0-20190911065817-5d6d842e92eb // v1.0
 	github.com/mattn/go-colorable v0.1.8
 	github.com/mbilski/exhaustivestruct v1.2.0
+	github.com/mgechev/dots v0.0.0-20190921121421-c36f7dcfbb81
+	github.com/mgechev/revive v1.0.3
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mitchellh/go-ps v1.0.0
 	github.com/moricho/tparallel v0.2.1
@@ -69,9 +71,8 @@ require (
 	github.com/ultraware/whitespace v0.0.4
 	github.com/uudashr/gocognit v1.0.1
 	github.com/valyala/quicktemplate v1.6.3
-	golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634 // indirect
 	golang.org/x/text v0.3.4 // indirect
-	golang.org/x/tools v0.0.0-20210105210202-9ed45478a130
+	golang.org/x/tools v0.1.0
 	gopkg.in/yaml.v2 v2.4.0
 	honnef.co/go/tools v0.0.1-2020.1.6
 	mvdan.cc/gofumpt v0.1.0

go.sum

@@ -268,6 +268,7 @@ type LintersSettings struct {
 	Gofumpt     GofumptSettings
 	ErrorLint   ErrorLintSettings
 	Makezero    MakezeroSettings
+	Revive      ReviveSettings
 	Thelper     ThelperSettings
 	Forbidigo   ForbidigoSettings
 	Ifshort     IfshortSettings
@@ -397,6 +398,23 @@ type MakezeroSettings struct {
 	Always bool
 }
 
+type ReviveSettings struct {
+	IgnoreGeneratedHeader bool `mapstructure:"ignore-generated-header"`
+	Confidence            float64
+	Severity              string
+	Rules                 []struct {
+		Name      string
+		Arguments []interface{}
+		Severity  string
+	}
+	ErrorCode   int `mapstructure:"error-code"`
+	WarningCode int `mapstructure:"warning-code"`
+	Directives  []struct {
+		Name     string
+		Severity string
+	}
+}
+
 type ThelperSettings struct {
 	Test struct {
 		First bool `mapstructure:"first"`

pkg/config/config.go

@@ -0,0 +1,173 @@
+package golinters
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/token"
+	"io/ioutil"
+
+	"github.com/mgechev/dots"
+	reviveConfig "github.com/mgechev/revive/config"
+	"github.com/mgechev/revive/lint"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/config"
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+	"github.com/golangci/golangci-lint/pkg/lint/linter"
+	"github.com/golangci/golangci-lint/pkg/result"
+)
+
+const reviveName = "revive"
+
+// jsonObject defines a JSON object of an failure
+type jsonObject struct {
+	Severity     lint.Severity
+	lint.Failure `json:",inline"`
+}
+
+// NewNewRevive returns a new Revive linter.
+func NewRevive(cfg *config.ReviveSettings) *goanalysis.Linter {
+	var issues []goanalysis.Issue
+
+	analyzer := &analysis.Analyzer{
+		Name: goanalysis.TheOnlyAnalyzerName,
+		Doc:  goanalysis.TheOnlyanalyzerDoc,
+	}
+
+	return goanalysis.NewLinter(
+		reviveName,
+		"Fast, configurable, extensible, flexible, and beautiful linter for Go. Drop-in replacement of golint.",
+		[]*analysis.Analyzer{analyzer},
+		nil,
+	).WithContextSetter(func(lintCtx *linter.Context) {
+		analyzer.Run = func(pass *analysis.Pass) (interface{}, error) {
+			var files []string
+
+			for _, file := range pass.Files {
+				files = append(files, pass.Fset.PositionFor(file.Pos(), false).Filename)
+			}
+
+			conf, err := setReviveConfig(cfg)
+			if err != nil {
+				return nil, err
+			}
+
+			formatter, err := reviveConfig.GetFormatter("json")
+			if err != nil {
+				return nil, err
+			}
+
+			revive := lint.New(ioutil.ReadFile)
+
+			lintingRules, err := reviveConfig.GetLintingRules(conf)
+			if err != nil {
+				return nil, err
+			}
+
+			packages, err := dots.ResolvePackages(files, []string{})
+			if err != nil {
+				return nil, err
+			}
+
+			failures, err := revive.Lint(packages, lintingRules, *conf)
+			if err != nil {
+				return nil, err
+			}
+
+			formatChan := make(chan lint.Failure)
+			exitChan := make(chan bool)
+
+			var output string
+			go func() {
+				output, err = formatter.Format(formatChan, *conf)
+				if err != nil {
+					lintCtx.Log.Errorf("Format error: %v", err)
+				}
+				exitChan <- true
+			}()
+
+			for f := range failures {
+				if f.Confidence < conf.Confidence {
+					continue
+				}
+
+				formatChan <- f
+			}
+
+			close(formatChan)
+			<-exitChan
+
+			var results []jsonObject
+			err = json.Unmarshal([]byte(output), &results)
+			if err != nil {
+				return nil, err
+			}
+
+			for i := range results {
+				issues = append(issues, goanalysis.NewIssue(&result.Issue{
+					Severity: string(results[i].Severity),
+					Text:     fmt.Sprintf("%q", results[i].Failure.Failure),
+					Pos: token.Position{
+						Filename: results[i].Position.Start.Filename,
+						Line:     results[i].Position.Start.Line,
+						Offset:   results[i].Position.Start.Offset,
+						Column:   results[i].Position.Start.Column,
+					},
+					LineRange: &result.Range{
+						From: results[i].Position.Start.Line,
+						To:   results[i].Position.End.Line,
+					},
+					FromLinter: reviveName,
+				}, pass))
+			}
+
+			return nil, nil
+		}
+	}).WithIssuesReporter(func(*linter.Context) []goanalysis.Issue {
+		return issues
+	}).WithLoadMode(goanalysis.LoadModeSyntax)
+}
+
+func setReviveConfig(cfg *config.ReviveSettings) (*lint.Config, error) {
+	// Get revive default configuration
+	conf, err := reviveConfig.GetConfig("")
+	if err != nil {
+		return nil, err
+	}
+
+	// Default is false
+	conf.IgnoreGeneratedHeader = cfg.IgnoreGeneratedHeader
+
+	if cfg.Severity != "" {
+		conf.Severity = lint.Severity(cfg.Severity)
+	}
+
+	if cfg.Confidence != 0 {
+		conf.Confidence = cfg.Confidence
+	}
+
+	// By default golangci-lint ignores missing doc comments, follow same convention by removing this default rule
+	// Relevant issue: https://github.com/golangci/golangci-lint/issues/456
+	delete(conf.Rules, "exported")
+
+	if len(cfg.Rules) != 0 {
+		// Clear default rules, only use rules defined in config
+		conf.Rules = make(map[string]lint.RuleConfig, len(cfg.Rules))
+	}
+	for _, r := range cfg.Rules {
+		conf.Rules[r.Name] = lint.RuleConfig{Arguments: r.Arguments, Severity: lint.Severity(r.Severity)}
+	}
+
+	conf.ErrorCode = cfg.ErrorCode
+	conf.WarningCode = cfg.WarningCode
+
+	if len(cfg.Directives) != 0 {
+		// Clear default Directives, only use Directives defined in config
+		conf.Directives = make(map[string]lint.DirectiveConfig, len(cfg.Directives))
+	}
+	for _, d := range cfg.Directives {
+		conf.Directives[d.Name] = lint.DirectiveConfig{Severity: lint.Severity(d.Severity)}
+	}
+
+	return conf, nil
+}

pkg/golinters/revive.go

@@ -96,6 +96,7 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 	var thelperCfg *config.ThelperSettings
 	var predeclaredCfg *config.PredeclaredSettings
 	var ifshortCfg *config.IfshortSettings
+	var reviveCfg *config.ReviveSettings
 	if m.cfg != nil {
 		govetCfg = &m.cfg.LintersSettings.Govet
 		testpackageCfg = &m.cfg.LintersSettings.Testpackage
@@ -104,6 +105,7 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 		thelperCfg = &m.cfg.LintersSettings.Thelper
 		predeclaredCfg = &m.cfg.LintersSettings.Predeclared
 		ifshortCfg = &m.cfg.LintersSettings.Ifshort
+		reviveCfg = &m.cfg.LintersSettings.Revive
 	}
 	const megacheckName = "megacheck"
 	lcs := []*linter.Config{
@@ -352,6 +354,9 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 		linter.NewConfig(golinters.NewPredeclared(predeclaredCfg)).
 			WithPresets(linter.PresetStyle).
 			WithURL("https://github.com/nishanths/predeclared"),
+		linter.NewConfig(golinters.NewRevive(reviveCfg)).
+			WithPresets(linter.PresetStyle).
+			WithURL("https://github.com/mgechev/revive"),
 
 		// nolintlint must be last because it looks at the results of all the previous linters for unused nolint directives
 		linter.NewConfig(golinters.NewNoLintLint()).

pkg/lint/lintersdb/manager.go

@@ -0,0 +1,7 @@
+linters-settings:
+  revive:
+    ignore-generated-header: true
+    severity: warning
+    rules:
+      - name: indent-error-flow
+        severity: warning

test/testdata/configs/revive.yml

@@ -0,0 +1,13 @@
+//args: -Erevive
+//config_path: testdata/configs/revive.yml
+package testdata
+
+import "time"
+
+func testRevive(t *time.Duration) error {
+	if t == nil {
+		return nil
+	} else { // ERROR "if block ends with a return statement, so drop this else and outdent its block"
+		return nil
+	}
+}