#156, #157: properly detect type errors in dependencies

pkg/golinters/megacheck.go

@@ -60,7 +60,7 @@ func (m Megacheck) Desc() string {
 }
 
 func prettifyCompilationError(err error) error {
-	i := TypeCheck{}.parseError(err)
+	i, _ := TypeCheck{}.parseError(err)
 	if i == nil {
 		return err
 	}

pkg/golinters/typecheck.go

@@ -2,6 +2,8 @@ package golinters
 
 import (
 	"context"
+	"errors"
+	"fmt"
 	"go/token"
 	"strconv"
 	"strings"
@@ -20,17 +22,19 @@ func (TypeCheck) Desc() string {
 	return "Like the front-end of a Go compiler, parses and type-checks Go code"
 }
 
-func (lint TypeCheck) parseError(err error) *result.Issue {
+func (lint TypeCheck) parseError(srcErr error) (*result.Issue, error) {
+	// TODO: cast srcErr to types.Error and just use it
+
 	// file:line(<optional>:colon): message
-	parts := strings.Split(err.Error(), ":")
+	parts := strings.Split(srcErr.Error(), ":")
 	if len(parts) < 3 {
-		return nil
+		return nil, errors.New("too few colons")
 	}
 
 	file := parts[0]
 	line, err := strconv.Atoi(parts[1])
 	if err != nil {
-		return nil
+		return nil, fmt.Errorf("can't parse line number %q: %s", parts[1], err)
 	}
 
 	var column int
@@ -48,7 +52,7 @@ func (lint TypeCheck) parseError(err error) *result.Issue {
 
 	message = strings.TrimSpace(message)
 	if message == "" {
-		return nil
+		return nil, fmt.Errorf("empty message")
 	}
 
 	return &result.Issue{
@@ -59,19 +63,17 @@ func (lint TypeCheck) parseError(err error) *result.Issue {
 		},
 		Text:       message,
 		FromLinter: lint.Name(),
-	}
+	}, nil
 }
 
 func (lint TypeCheck) Run(ctx context.Context, lintCtx *linter.Context) ([]result.Issue, error) {
-	if lintCtx.NotCompilingPackages == nil {
-		return nil, nil
-	}
-
 	var res []result.Issue
 	for _, pkg := range lintCtx.NotCompilingPackages {
 		for _, err := range pkg.Errors {
-			i := lint.parseError(err)
-			if i != nil {
+			i, perr := lint.parseError(err)
+			if perr != nil {
+				lintCtx.Log.Warnf("Can't parse type error %s: %s", err, perr)
+			} else {
 				res = append(res, *i)
 			}
 		}

pkg/golinters/typecheck_test.go

@@ -35,7 +35,7 @@ func TestParseError(t *testing.T) {
 
 	lint := TypeCheck{}
 	for _, c := range cases {
-		i := lint.parseError(errors.New(c.in))
+		i, _ := lint.parseError(errors.New(c.in))
 		if !c.good {
 			assert.Nil(t, i)
 			continue

pkg/lint/load.go

@@ -231,11 +231,14 @@ func buildSSAProgram(lprog *loader.Program, log logutils.Log) *ssa.Program {
 func separateNotCompilingPackages(lintCtx *linter.Context) {
 	prog := lintCtx.Program
 
+	notCompilingPackagesSet := map[*loader.PackageInfo]bool{}
+
 	if prog.Created != nil {
 		compilingCreated := make([]*loader.PackageInfo, 0, len(prog.Created))
 		for _, info := range prog.Created {
 			if len(info.Errors) != 0 {
 				lintCtx.NotCompilingPackages = append(lintCtx.NotCompilingPackages, info)
+				notCompilingPackagesSet[info] = true
 			} else {
 				compilingCreated = append(compilingCreated, info)
 			}
@@ -245,10 +248,27 @@ func separateNotCompilingPackages(lintCtx *linter.Context) {
 
 	if prog.Imported != nil {
 		for k, info := range prog.Imported {
-			if len(info.Errors) != 0 {
-				lintCtx.NotCompilingPackages = append(lintCtx.NotCompilingPackages, info)
-				delete(prog.Imported, k)
+			if len(info.Errors) == 0 {
+				continue
 			}
+
+			lintCtx.NotCompilingPackages = append(lintCtx.NotCompilingPackages, info)
+			notCompilingPackagesSet[info] = true
+			delete(prog.Imported, k)
+		}
+	}
+
+	if prog.AllPackages != nil {
+		for k, info := range prog.AllPackages {
+			if len(info.Errors) == 0 {
+				continue
+			}
+
+			if !notCompilingPackagesSet[info] {
+				lintCtx.NotCompilingPackages = append(lintCtx.NotCompilingPackages, info)
+				notCompilingPackagesSet[info] = true
+			}
+			delete(prog.AllPackages, k)
 		}
 	}