🔊 Annotate yaml when an error occurs

cmd/cmd.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/clevyr/go-yampl/internal/config"
+	"github.com/clevyr/go-yampl/internal/node"
 	"github.com/clevyr/go-yampl/internal/parser"
 	"github.com/clevyr/go-yampl/internal/visitor"
 	"github.com/goccy/go-yaml/ast"
@@ -152,8 +153,13 @@ func templateReader(conf config.Config, r io.Reader) (string, error) {
 
 	v := visitor.NewTemplateComments(conf)
 	for _, doc := range file.Docs {
-		if ast.Walk(&v, doc.Body); v.Error() != nil {
-			return "", v.Error()
+		ast.Walk(&v, doc.Body)
+		if err := v.Error(); err != nil {
+			switch err := err.(type) {
+			case node.PrintableError:
+				return "", fmt.Errorf("%w\n%v", err, err.AnnotateSource(file.String(), colored))
+			}
+			return "", err
 		}
 	}
 

cmd/flag_log.go

@@ -8,6 +8,7 @@ import (
 var (
 	logLevel  string
 	logFormat string
+	colored   bool
 )
 
 func init() {
@@ -54,8 +55,9 @@ func initLogFormat(format string) log.Formatter {
 	var formatter log.Formatter = &log.TextFormatter{}
 	switch format {
 	case "auto", "a":
-		break
+		colored = true
 	case "color", "c":
+		colored = true
 		formatter.(*log.TextFormatter).ForceColors = true
 	case "plain", "p":
 		formatter.(*log.TextFormatter).DisableColors = true

internal/node/printable_error.go

@@ -0,0 +1,36 @@
+package node
+
+import (
+	"github.com/goccy/go-yaml"
+	"github.com/goccy/go-yaml/ast"
+)
+
+func NewPrintableError(err error, node ast.Node) PrintableError {
+	return PrintableError{
+		err:  err,
+		node: node,
+	}
+}
+
+type PrintableError struct {
+	err  error
+	node ast.Node
+}
+
+func (p PrintableError) Error() string {
+	return p.err.Error()
+}
+
+func (p PrintableError) AnnotateSource(src string, colored bool) string {
+	path, err := yaml.PathString(p.node.GetPath())
+	if err != nil {
+		return ""
+	}
+
+	source, err := path.AnnotateSource([]byte(src), colored)
+	if err != nil {
+		return ""
+	}
+
+	return string(source)
+}

internal/visitor/template_comments.go

@@ -29,15 +29,15 @@ func (v *TemplateComments) Visit(n ast.Node) ast.Visitor {
 			newNode, err := templateComment(v.conf, comment, n.Value)
 			if err != nil {
 				if v.err == nil {
-					v.err = err
+					v.err = node.NewPrintableError(err, n)
 				}
 				return nil
 			}
 
 			if newNode != nil {
 				if err := n.Replace(newNode); err != nil {
 					if v.err == nil {
-						v.err = err
+						v.err = node.NewPrintableError(err, n)
 					}
 					return nil
 				}
@@ -49,15 +49,15 @@ func (v *TemplateComments) Visit(n ast.Node) ast.Visitor {
 				newNode, err := templateComment(v.conf, comment, value)
 				if err != nil {
 					if v.err == nil {
-						v.err = err
+						v.err = node.NewPrintableError(err, value)
 					}
 					return nil
 				}
 
 				if newNode != nil {
 					if err := n.Replace(i, newNode); err != nil {
 						if v.err == nil {
-							v.err = err
+							v.err = node.NewPrintableError(err, value)
 						}
 						return nil
 					}