Update golangci-lint configuration and fix code accordingly

.golangci.yml

@@ -29,17 +29,14 @@ issues:
       text: "does not use range value in test Run"
 
 linters-settings:
-  nolintlint:
-    # Disable to ensure that nolint directives don't have a leading space. Default is true.
-    allow-leading-space: false
   exhaustive:
     default-signifies-exhaustive: true
   govet:
-    check-shadowing: true
+    enable-all: true
+    disable:
+      - fieldalignment
   cyclop:
     max-complexity: 25
-  maligned:
-    suggest-new: true
   dupl:
     threshold: 150
   goconst:
@@ -52,6 +49,7 @@ linters-settings:
 linters:
   enable-all: true
   disable:
+    - depguard
     - nlreturn
     - gci
     - gochecknoinits
@@ -61,16 +59,11 @@ linters:
     - testpackage
     - wsl
     - gomnd
-    - goerr113 # most of the errors here are meant for humans
+    - err113
     - goheader
-    - exhaustivestruct
     - thelper
     - gocyclo # replaced by cyclop since it also calculates the package complexity
-    - maligned # replaced by govet 'fieldalignment'
-    - interfacer # deprecated
-    - scopelint # deprecated, replaced by exportloopref
     - wrapcheck # a little bit too much for k6, maybe after https://github.com/tomarrell/wrapcheck/issues/2 is fixed
-    - golint # this linter is deprecated
     - varnamelen
     - ireturn
     - tagliatelle
@@ -80,5 +73,4 @@ linters:
     - grouper
     - decorder
     - nonamedreturns
-    - nosnakecase
   fast: false

example_test.go

@@ -34,7 +34,12 @@ func ExampleGetField() {
 		if err != nil {
 			log.Fatal(err)
 		}
+
 		fmt.Println(value)
+
+		// output:
+		// first value
+		// third value
 	}
 }
 
@@ -62,6 +67,10 @@ func ExampleGetFieldKind() {
 		log.Fatal(err)
 	}
 	fmt.Println(secondFieldKind)
+
+	// output:
+	// string
+	// int
 }
 
 func ExampleGetFieldType() {
@@ -88,6 +97,10 @@ func ExampleGetFieldType() {
 		log.Fatal(err)
 	}
 	fmt.Println(secondFieldType)
+
+	// output:
+	// string
+	// int
 }
 
 func ExampleGetFieldTag() {
@@ -104,6 +117,10 @@ func ExampleGetFieldTag() {
 		log.Fatal(err)
 	}
 	fmt.Println(tag)
+
+	// output:
+	// first tag
+	// third tag
 }
 
 func ExampleHasField() {
@@ -120,6 +137,10 @@ func ExampleHasField() {
 	// has == false
 	has, _ = reflections.HasField(s, "FourthField")
 	fmt.Println(has)
+
+	// output:
+	// true
+	// false
 }
 
 func ExampleFields() {
@@ -136,6 +157,9 @@ func ExampleFields() {
 	// []string{"FirstField", "SecondField", "ThirdField"}
 	fields, _ = reflections.Fields(s)
 	fmt.Println(fields)
+
+	// output:
+	// [MyEmbeddedStruct FirstField SecondField ThirdField]
 }
 
 func ExampleItems() {
@@ -151,6 +175,9 @@ func ExampleItems() {
 	// field value map
 	structItems, _ = reflections.Items(s)
 	fmt.Println(structItems)
+
+	// output:
+	// map[FirstField:first value MyEmbeddedStruct:{} SecondField:2 ThirdField:third value]
 }
 
 func ExampleItemsDeep() {
@@ -170,6 +197,9 @@ func ExampleItemsDeep() {
 	// anonymous embedded structs
 	structItems, _ = reflections.ItemsDeep(s)
 	fmt.Println(structItems)
+
+	// output:
+	// map[EmbeddedField:embedded value FirstField:first value SecondField:2 ThirdField:third value]
 }
 
 func ExampleTags() {
@@ -191,6 +221,9 @@ func ExampleTags() {
 	// }
 	structTags, _ = reflections.Tags(s, "matched")
 	fmt.Println(structTags)
+
+	// output:
+	// map[FirstField:first tag MyEmbeddedStruct: SecondField:second tag ThirdField:]
 }
 
 func ExampleSetField() {
@@ -207,12 +240,11 @@ func ExampleSetField() {
 		log.Fatal(err)
 	}
 
-	// If you try to set a field's value using the wrong type,
+	// Note that if you try to set a field's value using the wrong type,
 	// an error will be returned
-	err = reflections.SetField(&s, "FirstField", 123) // err != nil
-	if err != nil {
-		log.Fatal(err)
-	}
+	_ = reflections.SetField(&s, "FirstField", 123) // err != nil
+
+	// output:
 }
 
 func ExampleGetFieldNameByTagValue() {

reflections.go

@@ -112,7 +112,7 @@ func GetFieldNameByTagValue(obj interface{}, tagKey, tagValue string) (string, e
 	objType := objValue.Type()
 	fieldsCount := objType.NumField()
 
-	for i := 0; i < fieldsCount; i++ {
+	for i := range fieldsCount {
 		structField := objType.Field(i)
 		if structField.Tag.Get(tagKey) == tagValue {
 			return structField.Name, nil
@@ -142,7 +142,7 @@ func SetField(obj interface{}, name string, value interface{}) error {
 	structFieldType := structFieldValue.Type()
 	val := reflect.ValueOf(value)
 	if !val.Type().AssignableTo(structFieldType) {
-		invalidTypeError := fmt.Errorf("provided value type not assignable to obj field type")
+		invalidTypeError := errors.New("provided value type not assignable to obj field type")
 		return invalidTypeError
 	}
 
@@ -175,7 +175,7 @@ func Fields(obj interface{}) ([]string, error) {
 
 // FieldsDeep returns "flattened" fields.
 //
-// Note that FieldsDeept treats fields from anonymous inner structs as normal fields.
+// Note that FieldsDeep treats fields from anonymous inner structs as normal fields.
 func FieldsDeep(obj interface{}) ([]string, error) {
 	return fields(obj, true)
 }
@@ -190,7 +190,7 @@ func fields(obj interface{}, deep bool) ([]string, error) {
 	fieldsCount := objType.NumField()
 
 	var allFields []string
-	for i := 0; i < fieldsCount; i++ {
+	for i := range fieldsCount {
 		field := objType.Field(i)
 		if isExportableField(field) {
 			if !deep || !field.Anonymous {
@@ -233,7 +233,7 @@ func items(obj interface{}, deep bool) (map[string]interface{}, error) {
 
 	allItems := make(map[string]interface{})
 
-	for i := 0; i < fieldsCount; i++ {
+	for i := range fieldsCount {
 		field := objType.Field(i)
 		fieldValue := objValue.Field(i)
 
@@ -281,7 +281,7 @@ func tags(obj interface{}, key string, deep bool) (map[string]string, error) {
 
 	allTags := make(map[string]string)
 
-	for i := 0; i < fieldsCount; i++ {
+	for i := range fieldsCount {
 		structField := objType.Field(i)
 		if isExportableField(structField) {
 			if !deep || !structField.Anonymous {