Allow revive to be called with extra linters (#650)

This change allows revive to be called from main.go
in other libraries and pass in a list of custom
linters to be added to the built-in linters found in config

Co-authored-by: Bernardo Heynemann <bernardo.heynemann@coinbase.com>
Co-authored-by: chavacava <salvadorcavadini+github@gmail.com>

cli/main.go

@@ -0,0 +1,281 @@
+package cli
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime/debug"
+	"strings"
+
+	"github.com/fatih/color"
+	"github.com/mgechev/dots"
+	"github.com/mgechev/revive/config"
+	"github.com/mgechev/revive/lint"
+	"github.com/mgechev/revive/logging"
+	"github.com/mitchellh/go-homedir"
+)
+
+var (
+	version = "dev"
+	commit  = "none"
+	date    = "unknown"
+	builtBy = "unknown"
+)
+
+func fail(err string) {
+	fmt.Fprintln(os.Stderr, err)
+	os.Exit(1)
+}
+
+// ExtraRule configures a new rule to be used with revive.
+type ExtraRule struct {
+	Rule          lint.Rule
+	DefaultConfig lint.RuleConfig
+}
+
+// NewExtraRule returns a configured extra rule
+func NewExtraRule(rule lint.Rule, defaultConfig lint.RuleConfig) ExtraRule {
+	return ExtraRule{
+		Rule:          rule,
+		DefaultConfig: defaultConfig,
+	}
+}
+
+// RunRevive runs the CLI for revive.
+func RunRevive(extraRules ...ExtraRule) {
+	log, err := logging.GetLogger()
+	if err != nil {
+		fail(err.Error())
+	}
+
+	formatter, err := config.GetFormatter(formatterName)
+	if err != nil {
+		fail(err.Error())
+	}
+
+	conf, err := config.GetConfig(configPath)
+	if err != nil {
+		fail(err.Error())
+	}
+
+	if setExitStatus {
+		conf.ErrorCode = 1
+		conf.WarningCode = 1
+	}
+
+	extraRuleInstances := make([]lint.Rule, len(extraRules))
+	for i, extraRule := range extraRules {
+		extraRuleInstances[i] = extraRule.Rule
+
+		ruleName := extraRule.Rule.Name()
+		_, isRuleAlreadyConfigured := conf.Rules[ruleName]
+		if !isRuleAlreadyConfigured {
+			conf.Rules[ruleName] = extraRule.DefaultConfig
+		}
+	}
+
+	lintingRules, err := config.GetLintingRules(conf, extraRuleInstances)
+	if err != nil {
+		fail(err.Error())
+	}
+
+	log.Println("Config loaded")
+
+	if len(excludePaths) == 0 { // if no excludes were set in the command line
+		excludePaths = conf.Exclude // use those from the configuration
+	}
+
+	packages, err := getPackages(excludePaths)
+	if err != nil {
+		fail(err.Error())
+	}
+	revive := lint.New(func(file string) ([]byte, error) {
+		return ioutil.ReadFile(file)
+	}, maxOpenFiles)
+
+	failures, err := revive.Lint(packages, lintingRules, *conf)
+	if err != nil {
+		fail(err.Error())
+	}
+
+	formatChan := make(chan lint.Failure)
+	exitChan := make(chan bool)
+
+	var output string
+	go (func() {
+		output, err = formatter.Format(formatChan, *conf)
+		if err != nil {
+			fail(err.Error())
+		}
+		exitChan <- true
+	})()
+
+	exitCode := 0
+	for f := range failures {
+		if f.Confidence < conf.Confidence {
+			continue
+		}
+		if exitCode == 0 {
+			exitCode = conf.WarningCode
+		}
+		if c, ok := conf.Rules[f.RuleName]; ok && c.Severity == lint.SeverityError {
+			exitCode = conf.ErrorCode
+		}
+		if c, ok := conf.Directives[f.RuleName]; ok && c.Severity == lint.SeverityError {
+			exitCode = conf.ErrorCode
+		}
+
+		formatChan <- f
+	}
+
+	close(formatChan)
+	<-exitChan
+	if output != "" {
+		fmt.Println(output)
+	}
+
+	os.Exit(exitCode)
+}
+
+func normalizeSplit(strs []string) []string {
+	res := []string{}
+	for _, s := range strs {
+		t := strings.Trim(s, " \t")
+		if len(t) > 0 {
+			res = append(res, t)
+		}
+	}
+	return res
+}
+
+func getPackages(excludePaths arrayFlags) ([][]string, error) {
+	globs := normalizeSplit(flag.Args())
+	if len(globs) == 0 {
+		globs = append(globs, ".")
+	}
+
+	packages, err := dots.ResolvePackages(globs, normalizeSplit(excludePaths))
+	if err != nil {
+		return nil, err
+	}
+
+	return packages, nil
+}
+
+type arrayFlags []string
+
+func (i *arrayFlags) String() string {
+	return strings.Join([]string(*i), " ")
+}
+
+func (i *arrayFlags) Set(value string) error {
+	*i = append(*i, value)
+	return nil
+}
+
+var (
+	configPath    string
+	excludePaths  arrayFlags
+	formatterName string
+	help          bool
+	versionFlag   bool
+	setExitStatus bool
+	maxOpenFiles  int
+)
+
+var originalUsage = flag.Usage
+
+func getLogo() string {
+	return color.YellowString(` _ __ _____   _(_)__  _____
+| '__/ _ \ \ / / \ \ / / _ \
+| | |  __/\ V /| |\ V /  __/
+|_|  \___| \_/ |_| \_/ \___|`)
+}
+
+func getCall() string {
+	return color.MagentaString("revive -config c.toml -formatter friendly -exclude a.go -exclude b.go ./...")
+}
+
+func getBanner() string {
+	return fmt.Sprintf(`
+%s
+
+Example:
+  %s
+`, getLogo(), getCall())
+}
+
+func buildDefaultConfigPath() string {
+	var result string
+	if homeDir, err := homedir.Dir(); err == nil {
+		result = filepath.Join(homeDir, "revive.toml")
+		if _, err := os.Stat(result); err != nil {
+			result = ""
+		}
+	}
+
+	return result
+}
+
+func init() {
+	// Force colorizing for no TTY environments
+	if os.Getenv("REVIVE_FORCE_COLOR") == "1" {
+		color.NoColor = false
+	}
+
+	flag.Usage = func() {
+		fmt.Println(getBanner())
+		originalUsage()
+	}
+
+	// command line help strings
+	const (
+		configUsage       = "path to the configuration TOML file, defaults to $HOME/revive.toml, if present (i.e. -config myconf.toml)"
+		excludeUsage      = "list of globs which specify files to be excluded (i.e. -exclude foo/...)"
+		formatterUsage    = "formatter to be used for the output (i.e. -formatter stylish)"
+		versionUsage      = "get revive version"
+		exitStatusUsage   = "set exit status to 1 if any issues are found, overwrites errorCode and warningCode in config"
+		maxOpenFilesUsage = "maximum number of open files at the same time"
+	)
+
+	defaultConfigPath := buildDefaultConfigPath()
+
+	flag.StringVar(&configPath, "config", defaultConfigPath, configUsage)
+	flag.Var(&excludePaths, "exclude", excludeUsage)
+	flag.StringVar(&formatterName, "formatter", "", formatterUsage)
+	flag.BoolVar(&versionFlag, "version", false, versionUsage)
+	flag.BoolVar(&setExitStatus, "set_exit_status", false, exitStatusUsage)
+	flag.IntVar(&maxOpenFiles, "max_open_files", 0, maxOpenFilesUsage)
+	flag.Parse()
+
+	// Output build info (version, commit, date and builtBy)
+	if versionFlag {
+		var buildInfo string
+		if date != "unknown" && builtBy != "unknown" {
+			buildInfo = fmt.Sprintf("Built\t\t%s by %s\n", date, builtBy)
+		}
+
+		if commit != "none" {
+			buildInfo = fmt.Sprintf("Commit:\t\t%s\n%s", commit, buildInfo)
+		}
+
+		if version == "dev" {
+			bi, ok := debug.ReadBuildInfo()
+			if ok {
+				version = bi.Main.Version
+				if strings.HasPrefix(version, "v") {
+					version = bi.Main.Version[1:]
+				}
+				if len(buildInfo) == 0 {
+					fmt.Printf("version %s\n", version)
+					os.Exit(0)
+				}
+			}
+		}
+
+		fmt.Printf("Version:\t%s\n%s", version, buildInfo)
+		os.Exit(0)
+	}
+}

config/config.go

@@ -107,11 +107,17 @@ func getFormatters() map[string]lint.Formatter {
 }
 
 // GetLintingRules yields the linting rules that must be applied by the linter
-func GetLintingRules(config *lint.Config) ([]lint.Rule, error) {
+func GetLintingRules(config *lint.Config, extraRules []lint.Rule) ([]lint.Rule, error) {
 	rulesMap := map[string]lint.Rule{}
 	for _, r := range allRules {
 		rulesMap[r.Name()] = r
 	}
+	for _, r := range extraRules {
+		if _, ok := rulesMap[r.Name()]; ok {
+			continue
+		}
+		rulesMap[r.Name()] = r
+	}
 
 	var lintingRules []lint.Rule
 	for name, ruleConfig := range config.Rules {

config/config_test.go

@@ -92,7 +92,7 @@ func TestGetLintingRules(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Unexpected error while loading conf: %v", err)
 			}
-			rules, err := GetLintingRules(cfg)
+			rules, err := GetLintingRules(cfg, []lint.Rule{})
 			switch {
 			case err != nil:
 				t.Fatalf("Unexpected error\n\t%v", err)
@@ -130,7 +130,7 @@ func TestGetGlobalSeverity(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Unexpected error while loading conf: %v", err)
 			}
-			rules, err := GetLintingRules(cfg)
+			rules, err := GetLintingRules(cfg, []lint.Rule{})
 			if err != nil {
 				t.Fatalf("Unexpected error while loading conf: %v", err)
 			}