importas: new option no-extra-aliases (golangci#2494)

.golangci.example.yml

@@ -559,8 +559,10 @@ linters-settings:
     max-decl-chars: 30
 
   importas:
-    # if set to `true`, force to use alias.
+    # Do not allow unaliased imports of aliased packages.
     no-unaliased: true
+    # Do not allow non-required aliases.
+    no-extra-aliases: true
     # List of aliases
     alias:
       # using `servingv1` alias for `knative.dev/serving/pkg/apis/serving/v1` package

go.mod

@@ -43,7 +43,7 @@ require (
 	github.com/jgautheron/goconst v1.5.1
 	github.com/jingyugao/rowserrcheck v1.1.1
 	github.com/jirfag/go-printf-func-name v0.0.0-20200119135958-7558a9eaa5af
-	github.com/julz/importas v0.0.0-20210419104244-841f0c0fe66d
+	github.com/julz/importas v0.1.0
 	github.com/kisielk/errcheck v1.6.0
 	github.com/kulti/thelper v0.5.0
 	github.com/kunwardeep/paralleltest v1.0.3

pkg/config/linters_settings.go

@@ -382,8 +382,9 @@ type IfshortSettings struct {
 }
 
 type ImportAsSettings struct {
-	Alias       []ImportAsAlias
-	NoUnaliased bool `mapstructure:"no-unaliased"`
+	Alias          []ImportAsAlias
+	NoUnaliased    bool `mapstructure:"no-unaliased"`
+	NoExtraAliases bool `mapstructure:"no-extra-aliases"`
 }
 
 type ImportAsAlias struct {

pkg/golinters/importas.go

@@ -28,8 +28,11 @@ func NewImportAs(settings *config.ImportAsSettings) *goanalysis.Linter {
 			lintCtx.Log.Infof("importas settings found, but no aliases listed. List aliases under alias: key.") // nolint: misspell
 		}
 
-		err := analyzer.Flags.Set("no-unaliased", strconv.FormatBool(settings.NoUnaliased))
-		if err != nil {
+		if err := analyzer.Flags.Set("no-unaliased", strconv.FormatBool(settings.NoUnaliased)); err != nil {
+			lintCtx.Log.Errorf("failed to parse configuration: %v", err)
+		}
+
+		if err := analyzer.Flags.Set("no-extra-aliases", strconv.FormatBool(settings.NoUnaliased)); err != nil {
 			lintCtx.Log.Errorf("failed to parse configuration: %v", err)
 		}