docs: improve goconst documentation. (#2128)

Author: ldez

.golangci.example.yml

@@ -179,8 +179,20 @@ linters-settings:
   goconst:
     # minimal length of string constant, 3 by default
     min-len: 3
-    # minimal occurrences count to trigger, 3 by default
+    # minimum occurrences of constant string count to trigger issue, 3 by default
     min-occurrences: 3
+    # ignore test files, false by default
+    ignore-tests: false
+    # look for existing constants matching the values, true by default
+    match-constant: true
+    # search also for duplicated numbers, false by default
+    numbers: false
+    # minimum value, only works with goconst.numbers, 3 by default
+    min: 3
+    # maximum value, only works with goconst.numbers, 3 by default
+    max: 3
+    # ignore when constant is not used as function argument, true by default
+    ignore-calls: true
 
   gocritic:
     # Which checks should be enabled; can't be combined with 'disabled-checks';

pkg/golinters/goconst.go

@@ -46,19 +46,23 @@ func NewGoconst() *goanalysis.Linter {
 }
 
 func checkConstants(pass *analysis.Pass, lintCtx *linter.Context) ([]goanalysis.Issue, error) {
+	settings := lintCtx.Settings().Goconst
+
 	cfg := goconstAPI.Config{
-		IgnoreTests:        lintCtx.Settings().Goconst.IgnoreTests,
-		MatchWithConstants: lintCtx.Settings().Goconst.MatchWithConstants,
-		MinStringLength:    lintCtx.Settings().Goconst.MinStringLen,
-		MinOccurrences:     lintCtx.Settings().Goconst.MinOccurrencesCount,
-		ParseNumbers:       lintCtx.Settings().Goconst.ParseNumbers,
-		NumberMin:          lintCtx.Settings().Goconst.NumberMin,
-		NumberMax:          lintCtx.Settings().Goconst.NumberMax,
+		IgnoreTests:        settings.IgnoreTests,
+		MatchWithConstants: settings.MatchWithConstants,
+		MinStringLength:    settings.MinStringLen,
+		MinOccurrences:     settings.MinOccurrencesCount,
+		ParseNumbers:       settings.ParseNumbers,
+		NumberMin:          settings.NumberMin,
+		NumberMax:          settings.NumberMax,
 		ExcludeTypes:       map[goconstAPI.Type]bool{},
 	}
-	if lintCtx.Settings().Goconst.IgnoreCalls {
+
+	if settings.IgnoreCalls {
 		cfg.ExcludeTypes[goconstAPI.Call] = true
 	}
+
 	goconstIssues, err := goconstAPI.Run(pass.Files, pass.Fset, &cfg)
 	if err != nil {
 		return nil, err