improve typecheck errors parsing

pkg/golinters/megacheck.go

@@ -88,7 +88,7 @@ func (m Megacheck) Run(ctx context.Context, lintCtx *linter.Context) ([]result.I
 		var errors []packages.Error
 		for _, p := range lintCtx.NotCompilingPackages {
 			errPkgs = append(errPkgs, p.String())
-			errors = append(errors, libpackages.ExtractErrors(p)...)
+			errors = append(errors, libpackages.ExtractErrors(p, lintCtx.ASTCache)...)
 		}
 
 		warnText := fmt.Sprintf("Can't run megacheck because of compilation errors in packages %s",

pkg/golinters/typecheck.go

@@ -2,12 +2,7 @@ package golinters
 
 import (
 	"context"
-	"fmt"
-	"go/token"
-	"strconv"
-	"strings"
 
-	"github.com/pkg/errors"
 	"golang.org/x/tools/go/packages"
 
 	"github.com/golangci/golangci-lint/pkg/lint/linter"
@@ -26,44 +21,31 @@ func (TypeCheck) Desc() string {
 }
 
 func (lint TypeCheck) parseError(srcErr packages.Error) (*result.Issue, error) {
-	// file:line(<optional>:colon)
-	parts := strings.Split(srcErr.Pos, ":")
-	if len(parts) == 1 {
-		return nil, errors.New("no colons")
-	}
-
-	file := parts[0]
-	line, err := strconv.Atoi(parts[1])
+	pos, err := libpackages.ParseErrorPosition(srcErr.Pos)
 	if err != nil {
-		return nil, fmt.Errorf("can't parse line number %q: %s", parts[1], err)
-	}
-
-	var column int
-	if len(parts) == 3 { // no column
-		column, err = strconv.Atoi(parts[2])
-		if err != nil {
-			return nil, errors.Wrapf(err, "failed to parse column from %q", parts[2])
-		}
+		return nil, err
 	}
 
 	return &result.Issue{
-		Pos: token.Position{
-			Filename: file,
-			Line:     line,
-			Column:   column,
-		},
+		Pos:        *pos,
 		Text:       srcErr.Msg,
 		FromLinter: lint.Name(),
 	}, nil
 }
 
 func (lint TypeCheck) Run(ctx context.Context, lintCtx *linter.Context) ([]result.Issue, error) {
+	uniqReportedIssues := map[string]bool{}
+
 	var res []result.Issue
 	for _, pkg := range lintCtx.NotCompilingPackages {
-		errors := libpackages.ExtractErrors(pkg)
+		errors := libpackages.ExtractErrors(pkg, lintCtx.ASTCache)
 		for _, err := range errors {
 			i, perr := lint.parseError(err)
 			if perr != nil { // failed to parse
+				if uniqReportedIssues[err.Msg] {
+					continue
+				}
+				uniqReportedIssues[err.Msg] = true
 				lintCtx.Log.Errorf("typechecking error: %s", err.Msg)
 			} else {
 				res = append(res, *i)

pkg/lint/load.go

@@ -334,7 +334,7 @@ func (cl ContextLoader) Load(ctx context.Context, linters []linter.Config) (*lin
 	} else {
 		for _, pkg := range pkgs {
 			if pkg.IllTyped {
-				cl.log.Infof("Pkg %s errors: %v", pkg.ID, libpackages.ExtractErrors(pkg))
+				cl.log.Infof("Pkg %s errors: %v", pkg.ID, libpackages.ExtractErrors(pkg, astCache))
 			}
 		}
 	}

pkg/packages/errors.go

@@ -0,0 +1,38 @@
+package packages
+
+import (
+	"fmt"
+	"go/token"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+func ParseErrorPosition(pos string) (*token.Position, error) {
+	// file:line(<optional>:colon)
+	parts := strings.Split(pos, ":")
+	if len(parts) == 1 {
+		return nil, errors.New("no colons")
+	}
+
+	file := parts[0]
+	line, err := strconv.Atoi(parts[1])
+	if err != nil {
+		return nil, fmt.Errorf("can't parse line number %q: %s", parts[1], err)
+	}
+
+	var column int
+	if len(parts) == 3 { // no column
+		column, err = strconv.Atoi(parts[2])
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to parse column from %q", parts[2])
+		}
+	}
+
+	return &token.Position{
+		Filename: file,
+		Line:     line,
+		Column:   column,
+	}, nil
+}

pkg/packages/util.go

@@ -3,10 +3,13 @@ package packages
 import (
 	"fmt"
 
+	"github.com/golangci/golangci-lint/pkg/lint/astcache"
+
 	"golang.org/x/tools/go/packages"
 )
 
-func ExtractErrors(pkg *packages.Package) []packages.Error {
+//nolint:gocyclo
+func ExtractErrors(pkg *packages.Package, astCache *astcache.Cache) []packages.Error {
 	errors := extractErrorsImpl(pkg)
 	if len(errors) == 0 {
 		return errors
@@ -22,17 +25,18 @@ func ExtractErrors(pkg *packages.Package) []packages.Error {
 		uniqErrors = append(uniqErrors, err)
 	}
 
-	if len(pkg.Errors) == 0 && len(pkg.GoFiles) != 0 {
-		// erorrs were extracted from deps and have at leat one file in package
-		for i := range uniqErrors {
-			// change pos to local file to properly process it by processors (properly read line etc)
-			uniqErrors[i].Msg = fmt.Sprintf("%s: %s", uniqErrors[i].Pos, uniqErrors[i].Msg)
-			uniqErrors[i].Pos = fmt.Sprintf("%s:1", pkg.GoFiles[0])
-		}
-	}
-
-	// some errors like "code in directory  expects import" don't have Pos, set it here
 	if len(pkg.GoFiles) != 0 {
+		// errors were extracted from deps and have at leat one file in package
+		for i := range uniqErrors {
+			errPos, parseErr := ParseErrorPosition(uniqErrors[i].Pos)
+			if parseErr != nil || astCache.Get(errPos.Filename) == nil {
+				// change pos to local file to properly process it by processors (properly read line etc)
+				uniqErrors[i].Msg = fmt.Sprintf("%s: %s", uniqErrors[i].Pos, uniqErrors[i].Msg)
+				uniqErrors[i].Pos = fmt.Sprintf("%s:1", pkg.GoFiles[0])
+			}
+		}
+
+		// some errors like "code in directory  expects import" don't have Pos, set it here
 		for i := range uniqErrors {
 			err := &uniqErrors[i]
 			if err.Pos == "" {

pkg/result/processors/autogenerated_exclude.go

@@ -42,6 +42,11 @@ func (p *AutogeneratedExclude) Process(issues []result.Issue) ([]result.Issue, e
 }
 
 func (p *AutogeneratedExclude) shouldPassIssue(i *result.Issue) (bool, error) {
+	if i.FromLinter == "typecheck" {
+		// don't hide typechecking errors in generated files: users expect to see why the project isn't compiling
+		return true, nil
+	}
+
 	fs, err := p.getOrCreateFileSummary(i)
 	if err != nil {
 		return false, err

test/run_test.go

@@ -24,7 +24,8 @@ func TestEmptyDirRun(t *testing.T) {
 
 func TestNotExistingDirRun(t *testing.T) {
 	testshared.NewLintRunner(t).Run(getTestDataDir("no_such_dir")).
-		ExpectHasIssue(`cannot find package \"./testdata/no_such_dir\"`)
+		ExpectExitCode(exitcodes.WarningInTest).
+		ExpectOutputContains(`cannot find package \"./testdata/no_such_dir\"`)
 }
 
 func TestSymlinkLoop(t *testing.T) {