Added shuffle command #1503

pkg/yqlib/operator_shuffle.go

@@ -0,0 +1,37 @@
+package yqlib
+
+import (
+	"container/list"
+	"fmt"
+	"math/rand"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func shuffleOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
+
+	// ignore CWE-338 gosec issue of not using crypto/rand
+	// this is just to shuffle an array rather generating a
+	// secret or something that needs proper rand.
+	myRand := rand.New(rand.NewSource(Now().UnixNano())) // #nosec
+
+	results := list.New()
+
+	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+
+		candidateNode := unwrapDoc(candidate.Node)
+
+		if candidateNode.Kind != yaml.SequenceNode {
+			return context, fmt.Errorf("node at path [%v] is not an array (it's a %v)", candidate.GetNicePath(), candidate.GetNiceTag())
+		}
+
+		result := deepClone(candidateNode)
+
+		a := result.Content
+
+		myRand.Shuffle(len(a), func(i, j int) { a[i], a[j] = a[j], a[i] })
+		results.PushBack(candidate.CreateReplacement(result))
+	}
+	return context.ChildContext(results), nil
+}