Add ForceTypeAssert linter (#1789)

Author: ldez

go.mod

@@ -31,6 +31,7 @@ require (
 	github.com/golangci/revgrep v0.0.0-20210208091834-cd28932614b5
 	github.com/golangci/unconvert v0.0.0-20180507085042-28b1c447d1f4
 	github.com/gordonklaus/ineffassign v0.0.0-20210225214923-2e10b2664254
+	github.com/gostaticanalysis/forcetypeassert v0.0.0-20200621232751-01d4955beaa5
 	github.com/gostaticanalysis/nilerr v0.1.1
 	github.com/jgautheron/goconst v1.4.0
 	github.com/jingyugao/rowserrcheck v0.0.0-20210130005344-c6a0c12dd98d

go.sum

@@ -0,0 +1,19 @@
+package golinters
+
+import (
+	"github.com/gostaticanalysis/forcetypeassert"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+)
+
+func NewForceTypeAssert() *goanalysis.Linter {
+	a := forcetypeassert.Analyzer
+
+	return goanalysis.NewLinter(
+		a.Name,
+		"finds forced type assertions",
+		[]*analysis.Analyzer{a},
+		nil,
+	).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}

pkg/golinters/forcetypeassert.go

@@ -390,6 +390,10 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithLoadForGoAnalysis().
 			WithPresets(linter.PresetBugs).
 			WithURL("https://github.com/gostaticanalysis/nilerr"),
+		linter.NewConfig(golinters.NewForceTypeAssert()).
+			WithPresets(linter.PresetStyle).
+			WithLoadForGoAnalysis().
+			WithURL("https://github.com/gostaticanalysis/forcetypeassert"),
 
 		// 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 +1,20 @@
+//args: -Eforcetypeassert
+package testdata
+
+import "fmt"
+
+func forcetypeassertInvalid() {
+	var a interface{}
+	_ = a.(int) // ERROR "type assertion must be checked"
+
+	var b interface{}
+	bi := b.(int) // ERROR "type assertion must be checked"
+	fmt.Println(bi)
+}
+
+func forcetypeassertValid() {
+	var a interface{}
+	if ai, ok := a.(int); ok {
+		fmt.Println(ai)
+	}
+}