fix: emit an error when no linters enabled (#6323)

Author: ldez

pkg/lint/runner.go

@@ -59,6 +59,15 @@ func NewRunner(log logutils.Log, cfg *config.Config, goenv *goutil.Env,
 		}
 	}
 
+	switch len(enabledLinters) {
+	case 0:
+		return nil, errors.New("no linters enabled")
+	case 1:
+		if _, ok := enabledLinters["typecheck"]; ok {
+			return nil, errors.New("no linters enabled")
+		}
+	}
+
 	formattersCfg := &config.Formatters{
 		Enable:   enabledFormatters,
 		Settings: cfg.Linters.Settings.FormatterSettings,

test/run_test.go

@@ -70,6 +70,24 @@ func TestNotExistingDirRun(t *testing.T) {
 		ExpectOutputContains(testshared.NormalizeFileInString("/testdata/no_such_dir"))
 }
 
+func TestNoLintersEnabled(t *testing.T) {
+	cfg := `
+version: "2"
+linters:
+	default: none
+	enable: []
+`
+
+	testshared.NewRunnerBuilder(t).
+		WithConfig(cfg).
+		WithArgs("--show-stats=false").
+		WithTargetPath(testdataDir, "autogenerated").
+		Runner().
+		Install().
+		Run().
+		ExpectOutputContains("Running error: no linters enabled")
+}
+
 func TestSymlinkLoop(t *testing.T) {
 	testshared.NewRunnerBuilder(t).
 		WithArgs("--show-stats=false").

test/testdata/notcompiles/typecheck.go

@@ -1,4 +1,5 @@
-//golangcitest:args -Etypecheck
+//golangcitest:args -Emodernize
+//golangcitest:expected_linter typecheck
 package testdata
 
 fun NotCompiles() { // want "expected declaration, found.* fun"

test/testdata/notcompiles/typecheck_many_issues.go

@@ -1,6 +1,7 @@
 //go:build go1.20
 
-//golangcitest:args -Etypecheck
+//golangcitest:args -Emodernize
+//golangcitest:expected_linter typecheck
 package testdata
 
 func TypeCheckBadCalls() {