Added more support for YAML merge nodes, anchors and aliases

And added deeper support for Aliases. Also added in local file handling through renamed `FSHandler` configuration property for the index.

Also re-ran `go fmt`

Signed-off-by: Dave Shanley <dave@quobix.com>

utils/utils.go

@@ -196,9 +196,9 @@ func FindFirstKeyNode(key string, nodes []*yaml.Node, depth int) (keyNode *yaml.
 	for i, v := range nodes {
 		if key != "" && key == v.Value {
 			if i+1 >= len(nodes) {
-				return v, nodes[i] // this is the node we need.
+				return v, NodeAlias(nodes[i]) // this is the node we need.
 			}
-			return v, nodes[i+1] // next node is what we need.
+			return v, NodeAlias(nodes[i+1]) // next node is what we need.
 		}
 		if len(v.Content) > 0 {
 			depth++
@@ -283,12 +283,12 @@ func FindKeyNodeFull(key string, nodes []*yaml.Node) (keyNode *yaml.Node, labelN
 			if key == v.Content[x].Value {
 				if IsNodeMap(v) {
 					if x+1 == len(v.Content) {
-						return v, v.Content[x], v.Content[x]
+						return v, v.Content[x], NodeAlias(v.Content[x])
 					}
-					return v, v.Content[x], v.Content[x+1]
+					return v, v.Content[x], NodeAlias(v.Content[x+1])
 				}
 				if IsNodeArray(v) {
-					return v, v.Content[x], v.Content[x]
+					return v, v.Content[x], NodeAlias(v.Content[x])
 				}
 			}
 		}
@@ -304,7 +304,7 @@ func FindKeyNodeFullTop(key string, nodes []*yaml.Node) (keyNode *yaml.Node, lab
 			continue
 		}
 		if i%2 == 0 && key == nodes[i].Value {
-			return nodes[i], nodes[i], nodes[i+1] // next node is what we need.
+			return nodes[i], nodes[i], NodeAlias(nodes[i+1]) // next node is what we need.
 		}
 	}
 	return nil, nil, nil
@@ -322,7 +322,7 @@ func FindExtensionNodes(nodes []*yaml.Node) []*ExtensionNode {
 			if i+1 < len(nodes) {
 				extensions = append(extensions, &ExtensionNode{
 					Key:   v,
-					Value: nodes[i+1],
+					Value: NodeAlias(nodes[i+1]),
 				})
 			}
 		}
@@ -363,12 +363,38 @@ func IsNodeMap(node *yaml.Node) bool {
 	if node == nil {
 		return false
 	}
-	return node.Tag == "!!map"
+	n := NodeAlias(node)
+	return n.Tag == "!!map"
+}
+
+// IsNodeAlias checks if the node is an alias, and lifts out the anchor
+func IsNodeAlias(node *yaml.Node) (*yaml.Node, bool) {
+	if node == nil {
+		return nil, false
+	}
+	if node.Kind == yaml.AliasNode {
+		node = node.Alias
+		return node, true
+	}
+	return node, false
+}
+
+// NodeAlias checks if the node is an alias, and lifts out the anchor
+func NodeAlias(node *yaml.Node) *yaml.Node {
+	if node == nil {
+		return nil
+	}
+	if node.Kind == yaml.AliasNode {
+		node = node.Alias
+		return node
+	}
+	return node
 }
 
 // IsNodePolyMorphic will return true if the node contains polymorphic keys.
 func IsNodePolyMorphic(node *yaml.Node) bool {
-	for i, v := range node.Content {
+	n := NodeAlias(node)
+	for i, v := range n.Content {
 		if i%2 == 0 {
 			if v.Value == "anyOf" || v.Value == "oneOf" || v.Value == "allOf" {
 				return true
@@ -383,7 +409,8 @@ func IsNodeArray(node *yaml.Node) bool {
 	if node == nil {
 		return false
 	}
-	return node.Tag == "!!seq"
+	n := NodeAlias(node)
+	return n.Tag == "!!seq"
 }
 
 // IsNodeStringValue checks if a node is a string value
@@ -391,7 +418,8 @@ func IsNodeStringValue(node *yaml.Node) bool {
 	if node == nil {
 		return false
 	}
-	return node.Tag == "!!str"
+	n := NodeAlias(node)
+	return n.Tag == "!!str"
 }
 
 // IsNodeIntValue will check if a node is an int value
@@ -399,7 +427,8 @@ func IsNodeIntValue(node *yaml.Node) bool {
 	if node == nil {
 		return false
 	}
-	return node.Tag == "!!int"
+	n := NodeAlias(node)
+	return n.Tag == "!!int"
 }
 
 // IsNodeFloatValue will check is a node is a float value.
@@ -407,7 +436,8 @@ func IsNodeFloatValue(node *yaml.Node) bool {
 	if node == nil {
 		return false
 	}
-	return node.Tag == "!!float"
+	n := NodeAlias(node)
+	return n.Tag == "!!float"
 }
 
 // IsNodeNumberValue will check if a node can be parsed as a float value.
@@ -423,18 +453,20 @@ func IsNodeBoolValue(node *yaml.Node) bool {
 	if node == nil {
 		return false
 	}
-	return node.Tag == "!!bool"
+	n := NodeAlias(node)
+	return n.Tag == "!!bool"
 }
 
 func IsNodeRefValue(node *yaml.Node) (bool, *yaml.Node, string) {
+
 	if node == nil {
 		return false, nil, ""
 	}
-
-	for i, r := range node.Content {
+	n := NodeAlias(node)
+	for i, r := range n.Content {
 		if i%2 == 0 {
 			if r.Value == "$ref" {
-				return true, r, node.Content[i+1].Value
+				return true, r, n.Content[i+1].Value
 			}
 		}
 	}
@@ -691,3 +723,26 @@ func DetermineWhitespaceLength(input string) int {
 		return 0
 	}
 }
+
+// CheckForMergeNodes will check the top level of the schema for merge nodes. If any are found, then the merged nodes
+// will be appended to the end of the rest of the nodes in the schema.
+// Note: this is a destructive operation, so the in-memory node structure will be modified
+func CheckForMergeNodes(node *yaml.Node) {
+	if node == nil {
+		return
+	}
+	total := len(node.Content)
+	for i := 0; i < total; i++ {
+		mn := node.Content[i]
+		if i%2 == 0 {
+			if mn.Tag == "!!merge" {
+				an := node.Content[i+1].Alias
+				if an != nil {
+					node.Content = append(node.Content, an.Content...) // append the merged nodes
+					total = len(node.Content)
+					i += 2
+				}
+			}
+		}
+	}
+}