Use errcheck from main repo instead of golangci-lint

Author: Sergey Vilgelm

.github/workflows/pr.yml

@@ -33,6 +33,7 @@ jobs:
         uses: golangci/[email protected]
         with:
           version: latest
+          args: --verbose
   tests-on-windows:
     needs: golangci-lint # run after golangci-lint action to not produce duplicated errors
     runs-on: windows-latest

go.mod

@@ -17,7 +17,6 @@ require (
 	github.com/gofrs/flock v0.8.0
 	github.com/golangci/check v0.0.0-20180506172741-cfe4005ccda2
 	github.com/golangci/dupl v0.0.0-20180902072040-3e9179ac440a
-	github.com/golangci/errcheck v0.0.0-20181223084120-ef45e06d44b6
 	github.com/golangci/go-misc v0.0.0-20180628070357-927a3d87b613
 	github.com/golangci/gocyclo v0.0.0-20180528144436-0a533e8fa43d
 	github.com/golangci/gofmt v0.0.0-20190930125516-244bba706f1a
@@ -34,6 +33,8 @@ require (
 	github.com/kulti/thelper v0.1.0
 	github.com/kunwardeep/paralleltest v1.0.2
 	github.com/kyoh86/exportloopref v0.1.8
+	github.com/kisielk/errcheck v1.4.1-0.20200802052755-ea6ea2fa7078
+	github.com/kyoh86/exportloopref v0.1.7
 	github.com/maratori/testpackage v1.0.1
 	github.com/matoous/godox v0.0.0-20190911065817-5d6d842e92eb // v1.0
 	github.com/mattn/go-colorable v0.1.8
@@ -77,3 +78,5 @@ require (
 	mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b // indirect
 	mvdan.cc/unparam v0.0.0-20200501210554-b37ab49443f7
 )
+
+replace github.com/kisielk/errcheck => /Users/[email protected]/icloud/projects/errcheck

go.sum

@@ -205,7 +205,9 @@ func computeConfigSalt(cfg *config.Config) ([]byte, error) {
 	configData.WriteString("\nbuild-tags=%s" + strings.Join(cfg.Run.BuildTags, ","))
 
 	h := sha256.New()
-	h.Write(configData.Bytes()) //nolint:errcheck
+	if _, err := h.Write(configData.Bytes()); err != nil {
+		return nil, err
+	}
 	return h.Sum(nil), nil
 }
 

pkg/commands/executor.go

@@ -10,9 +10,10 @@ import (
 	"strings"
 	"sync"
 
-	errcheck "github.com/golangci/errcheck/golangci"
+	"github.com/kisielk/errcheck/errcheck"
 	"github.com/pkg/errors"
 	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/packages"
 
 	"github.com/golangci/golangci-lint/pkg/config"
 	"github.com/golangci/golangci-lint/pkg/fsutils"
@@ -36,17 +37,23 @@ func NewErrcheck() *goanalysis.Linter {
 		[]*analysis.Analyzer{analyzer},
 		nil,
 	).WithContextSetter(func(lintCtx *linter.Context) {
+		// copied from errcheck
+		checker, err := getChecker(&lintCtx.Settings().Errcheck)
+		if err != nil {
+			panic(err.Error())
+		}
+		checker.Verbose = lintCtx.Cfg.Run.IsVerbose
+		checker.Tags = lintCtx.Cfg.Run.BuildTags
+
 		analyzer.Run = func(pass *analysis.Pass) (interface{}, error) {
-			prog := goanalysis.MakeFakeLoaderProgram(pass)
-			errCfg, err := genConfig(&lintCtx.Settings().Errcheck)
-			if err != nil {
-				return nil, err
-			}
-			errcheckIssues, err := errcheck.RunWithConfig(prog, errCfg)
-			if err != nil {
-				return nil, err
+			pkg := &packages.Package{
+				Fset:      pass.Fset,
+				Syntax:    pass.Files,
+				Types:     pass.Pkg,
+				TypesInfo: pass.TypesInfo,
 			}
 
+			errcheckIssues := checker.CheckPackage(pkg)
 			if len(errcheckIssues) == 0 {
 				return nil, nil
 			}
@@ -104,27 +111,32 @@ func parseIgnoreConfig(s string) (map[string]*regexp.Regexp, error) {
 	return cfg, nil
 }
 
-func genConfig(errCfg *config.ErrcheckSettings) (*errcheck.Config, error) {
+func getChecker(errCfg *config.ErrcheckSettings) (*errcheck.Checker, error) {
+	checker := errcheck.NewChecker()
+	checker.Blank = errCfg.CheckAssignToBlank
+	checker.Asserts = errCfg.CheckTypeAssertions
+
 	ignoreConfig, err := parseIgnoreConfig(errCfg.Ignore)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to parse 'ignore' directive")
 	}
 
-	c := &errcheck.Config{
-		Ignore:  ignoreConfig,
-		Blank:   errCfg.CheckAssignToBlank,
-		Asserts: errCfg.CheckTypeAssertions,
+	checker.Ignore = map[string]*regexp.Regexp{}
+	for pkg, re := range ignoreConfig {
+		checker.Ignore[pkg] = re
 	}
+	checker.UpdateNonVendoredIgnore()
 
+	checker.AddExcludes(errcheck.DefaultExcludes)
 	if errCfg.Exclude != "" {
 		exclude, err := readExcludeFile(errCfg.Exclude)
 		if err != nil {
 			return nil, err
 		}
-		c.Exclude = exclude
+		checker.AddExcludes(exclude)
 	}
 
-	return c, nil
+	return checker, nil
 }
 
 func getFirstPathArg() string {
@@ -192,7 +204,7 @@ func setupConfigFileSearch(name string) []string {
 	return configSearchPaths
 }
 
-func readExcludeFile(name string) (map[string]bool, error) {
+func readExcludeFile(name string) ([]string, error) {
 	var err error
 	var fh *os.File
 
@@ -206,12 +218,12 @@ func readExcludeFile(name string) (map[string]bool, error) {
 		return nil, errors.Wrapf(err, "failed reading exclude file: %s", name)
 	}
 	scanner := bufio.NewScanner(fh)
-	exclude := make(map[string]bool)
+	excludes := []string{}
 	for scanner.Scan() {
-		exclude[scanner.Text()] = true
+		excludes = append(excludes, scanner.Text())
 	}
 	if err := scanner.Err(); err != nil {
 		return nil, errors.Wrapf(err, "failed scanning file: %s", name)
 	}
-	return exclude, nil
+	return excludes, nil
 }

pkg/golinters/errcheck.go

@@ -55,7 +55,9 @@ func updateStateFile(replacements map[string]string) error {
 	}
 
 	h := sha256.New()
-	h.Write(replBytes) //nolint:errcheck
+	if _, err := h.Write(replBytes); err != nil {
+		return err
+	}
 
 	var contentBuf bytes.Buffer
 	contentBuf.WriteString("This file stores hash of website templates to trigger " +

scripts/expand_website_templates/main.go

@@ -135,7 +135,7 @@ func TestSortedResults(t *testing.T) {
 			"--sort-results=false",
 			strings.Join([]string{
 				"testdata/sort_results/main.go:12:5: `db` is unused (deadcode)",
-				"testdata/sort_results/main.go:15:13: Error return value of `returnError` is not checked (errcheck)",
+				"testdata/sort_results/main.go:15:13: Error return value is not checked (errcheck)",
 				"testdata/sort_results/main.go:8:6: func `returnError` is unused (unused)",
 			}, "\n"),
 		},
@@ -144,7 +144,7 @@ func TestSortedResults(t *testing.T) {
 			strings.Join([]string{
 				"testdata/sort_results/main.go:8:6: func `returnError` is unused (unused)",
 				"testdata/sort_results/main.go:12:5: `db` is unused (deadcode)",
-				"testdata/sort_results/main.go:15:13: Error return value of `returnError` is not checked (errcheck)",
+				"testdata/sort_results/main.go:15:13: Error return value is not checked (errcheck)",
 			}, "\n"),
 		},
 	}

test/run_test.go

@@ -12,7 +12,7 @@ func RetErr() error {
 }
 
 func MissedErrorCheck() {
-	RetErr() // ERROR "Error return value of `RetErr` is not checked"
+	RetErr() // ERROR "Error return value is not checked"
 }
 
 func IgnoreCloseMissingErrHandling() error {

test/testdata/errcheck.go

@@ -13,6 +13,6 @@ func TestErrcheckExclude() []byte {
 }
 
 func TestErrcheckNoExclude() []byte {
-	ret, _ := ioutil.ReadAll(nil) // ERROR "Error return value of `ioutil.ReadAll` is not checked"
+	ret, _ := ioutil.ReadAll(nil) // ERROR "Error return value is not checked"
 	return ret
 }

test/testdata/errcheck_exclude.go

@@ -13,7 +13,7 @@ func TestErrcheckIgnoreOs() {
 }
 
 func TestErrcheckNoIgnoreFmt(s string) int {
-	n, _ := fmt.Println(s) // ERROR "Error return value of `fmt.Println` is not checked"
+	n, _ := fmt.Println(s) // ERROR "Error return value is not checked"
 	return n
 }
 
@@ -23,6 +23,6 @@ func TestErrcheckIgnoreIoutil() []byte {
 }
 
 func TestErrcheckNoIgnoreIoutil() []byte {
-	ret, _ := ioutil.ReadAll(nil) // ERROR "Error return value of `ioutil.ReadAll` is not checked"
+	ret, _ := ioutil.ReadAll(nil) // ERROR "Error return value is not checked"
 	return ret
 }

test/testdata/errcheck_ignore.go

@@ -3,15 +3,22 @@
 package testdata
 
 import (
+	"crypto/sha256"
 	"fmt"
 	"os"
 )
 
+func TestErrcheckIgnoreHashWriteByDefault() []byte {
+	h := sha256.New()
+	h.Write([]byte("food"))
+	return h.Sum(nil)
+}
+
 func TestErrcheckIgnoreFmtByDefault(s string) int {
 	n, _ := fmt.Println(s)
 	return n
 }
 
 func TestErrcheckNoIgnoreOs() {
-	_, _ = os.Open("f.txt") // ERROR "Error return value of `os.Open` is not checked"
+	_, _ = os.Open("f.txt") // ERROR "Error return value is not checked"
 }

test/testdata/errcheck_ignore_default.go

@@ -0,0 +1,7 @@
+//args: -Eerrcheck
+//config: linters-settings.errcheck.check-type-assertions=true
+package testdata
+
+func ErrorTypeAssertion(filter map[string]interface{}) bool {
+	return filter["messages_sent.messageid"].(map[string]interface{})["$ne"] != nil
+}