new yaml parser, runner

engine/runner/parse/node_error.go

@@ -0,0 +1,40 @@
+package parse
+
+import "fmt"
+
+// ErrorNode executes the body node, and then executes the error node if
+// the body node errors. This is similar to defer but only executes on error.
+type ErrorNode struct {
+	NodeType `json:"type"`
+
+	Body  Node `json:"body"`  // evaluate node
+	Defer Node `json:"defer"` // defer evaluation of node on error.
+}
+
+// NewErrorNode returns a new ErrorNode.
+func NewErrorNode() *ErrorNode {
+	return &ErrorNode{NodeType: NodeError}
+}
+
+func (n *ErrorNode) SetBody(node Node) *ErrorNode {
+	n.Body = node
+	return n
+}
+
+func (n *ErrorNode) SetDefer(node Node) *ErrorNode {
+	n.Defer = node
+	return n
+}
+
+func (n *ErrorNode) Validate() error {
+	switch {
+	case n.NodeType != NodeError:
+		return fmt.Errorf("Error Node uses an invalid type")
+	case n.Body == nil:
+		return fmt.Errorf("Error Node body is empty")
+	case n.Defer == nil:
+		return fmt.Errorf("Error Node defer is empty")
+	default:
+		return nil
+	}
+}