enable revive linter

.github/workflows/go.yml

@@ -16,6 +16,12 @@ jobs:
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
       
+    - name: Setup golangci-lint
+      uses: golangci/golangci-lint-action@v2
+      with:
+        version: latest
+        args: --verbose
+       
     - name: Get dependencies
       run: |
         go get -v -t -d ./...

.golangci.yml

@@ -8,9 +8,16 @@ linters:
     - goimports
     - gosec
     - misspell
+    - revive
 issues:
   exclude-rules:
   - linters:
     - gosec
     text:  "Implicit memory aliasing in for loop."
     path: _test\.go
+  - linters:
+    - revive
+    text: "unexported-return"
+  - linters:
+    - revive
+    text: "var-naming"

pkg/yqlib/all_at_once_evaluator.go

@@ -50,7 +50,7 @@ func (e *allAtOnceEvaluator) EvaluateFiles(expression string, filenames []string
 	fileIndex := 0
 	firstFileLeadingContent := ""
 
-	var allDocuments *list.List = list.New()
+	var allDocuments = list.New()
 	for _, filename := range filenames {
 		reader, leadingContent, err := readStream(filename, fileIndex == 0 && leadingContentPreProcessing)
 		if err != nil {

pkg/yqlib/candidate_node.go

@@ -56,7 +56,7 @@ func (n *CandidateNode) AsList() *list.List {
 }
 
 func (n *CandidateNode) CreateChildInMap(key *yaml.Node, node *yaml.Node) *CandidateNode {
-	var value interface{} = nil
+	var value interface{}
 	if key != nil {
 		value = key.Value
 	}

pkg/yqlib/operator_anchors_aliases.go

@@ -220,7 +220,7 @@ func explodeNode(node *yaml.Node, context Context) error {
 		if hasAlias {
 			// this is a slow op, which is why we want to check before running it.
 			return reconstructAliasedMap(node, context)
-		} else {
+		}
 		// this map has no aliases, but it's kids might
 		for index := 0; index < len(node.Content); index = index + 2 {
 			keyNode := node.Content[index]
@@ -235,7 +235,6 @@ func explodeNode(node *yaml.Node, context Context) error {
 			}
 		}
 		return nil
-		}
 	default:
 		return nil
 	}

pkg/yqlib/operator_collect_object.go

@@ -28,7 +28,7 @@ func collectObjectOperator(d *dataTreeNavigator, originalContext Context, expres
 		return context.SingleChildContext(candidate), nil
 	}
 	first := context.MatchingNodes.Front().Value.(*CandidateNode)
-	var rotated []*list.List = make([]*list.List, len(first.Node.Content))
+	var rotated = make([]*list.List, len(first.Node.Content))
 
 	for i := 0; i < len(first.Node.Content); i++ {
 		rotated[i] = list.New()

pkg/yqlib/operator_create_map.go

@@ -14,7 +14,7 @@ func createMapOperator(d *dataTreeNavigator, context Context, expressionNode *Ex
 
 	var path []interface{}
 
-	var document uint = 0
+	var document uint
 
 	sequences := list.New()
 
@@ -42,7 +42,7 @@ func createMapOperator(d *dataTreeNavigator, context Context, expressionNode *Ex
 
 func sequenceFor(d *dataTreeNavigator, context Context, matchingNode *CandidateNode, expressionNode *ExpressionNode) (*CandidateNode, error) {
 	var path []interface{}
-	var document uint = 0
+	var document uint
 	var matches = list.New()
 
 	if matchingNode != nil {

pkg/yqlib/operator_multiply.go

@@ -114,7 +114,7 @@ func mergeObjects(d *dataTreeNavigator, context Context, lhs *CandidateNode, rhs
 		return nil, err
 	}
 
-	var pathIndexToStartFrom int = 0
+	var pathIndexToStartFrom int
 	if results.Front() != nil {
 		pathIndexToStartFrom = len(results.Front().Value.(*CandidateNode).Path)
 	}

pkg/yqlib/operator_split_document.go

@@ -3,7 +3,7 @@ package yqlib
 func splitDocumentOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
 	log.Debugf("-- splitDocumentOperator")
 
-	var index uint = 0
+	var index uint
 	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
 		candidate := el.Value.(*CandidateNode)
 		candidate.Document = index

pkg/yqlib/operator_strings.go

@@ -62,7 +62,7 @@ func substituteStringOperator(d *dataTreeNavigator, context Context, expressionN
 		candidate := el.Value.(*CandidateNode)
 		node := unwrapDoc(candidate.Node)
 		if node.Tag != "!!str" {
-			return Context{}, fmt.Errorf("cannot substitute with %v, can only substitute strings. Hint: Most often you'll want to use '|=' over '=' for this operation.", node.Tag)
+			return Context{}, fmt.Errorf("cannot substitute with %v, can only substitute strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
 		}
 
 		targetNode := substitute(node.Value, regEx, replacementText)

pkg/yqlib/operators_test.go

@@ -91,7 +91,7 @@ func testScenario(t *testing.T, s *expressionScenario) {
 }
 
 func resultsToString(t *testing.T, results *list.List) []string {
-	var pretty []string = make([]string, 0)
+	var pretty = make([]string, 0)
 
 	for el := results.Front(); el != nil; el = el.Next() {
 		n := el.Value.(*CandidateNode)

pkg/yqlib/stream_evaluator.go

@@ -52,7 +52,7 @@ func (s *streamEvaluator) EvaluateNew(expression string, printer Printer, leadin
 }
 
 func (s *streamEvaluator) EvaluateFiles(expression string, filenames []string, printer Printer, leadingContentPreProcessing bool) error {
-	var totalProcessDocs uint = 0
+	var totalProcessDocs uint
 	node, err := s.treeCreator.ParseExpression(expression)
 	if err != nil {
 		return err

pkg/yqlib/utils.go

@@ -110,7 +110,7 @@ func processReadStream(reader *bufio.Reader) (io.Reader, string, error) {
 func readDocuments(reader io.Reader, filename string, fileIndex int) (*list.List, error) {
 	decoder := yaml.NewDecoder(reader)
 	inputList := list.New()
-	var currentIndex uint = 0
+	var currentIndex uint
 
 	for {
 		var dataBucket yaml.Node