Add more information in some errors

pkg/processors/frontmatter.go

@@ -5,6 +5,7 @@
 package processors
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/gardener/docforge/pkg/api"
@@ -59,7 +60,7 @@ func (f *FrontMatter) Process(document *Document) error {
 	fmBytes = document.FrontMatter
 	docFm = map[string]interface{}{}
 	if err := yaml.Unmarshal(fmBytes, docFm); err != nil {
-		return err
+		return fmt.Errorf("failed to unmarsal the document frontmatter. %+v", err)
 	}
 
 	for propertyKey, propertyValue := range docFm {

pkg/reactor/document_worker.go

@@ -142,12 +142,12 @@ func (w *DocumentWorker) Work(ctx context.Context, task interface{}) error {
 			doc.Append(documentBytes)
 			if w.Processor != nil {
 				if err := w.Processor.Process(doc); err != nil {
-					return err
+					return fmt.Errorf("failed to process the document: %s. %+v", doc.Node.Source, err)
 				}
 			}
 			documentBytes = doc.DocumentBytes
 			if documentBytes, err = markdown.InsertFrontMatter(doc.FrontMatter, documentBytes); err != nil {
-				return err
+				return fmt.Errorf("failed to insert frontmatter to document: %s. %+v", doc.Node.Source, err)
 			}
 		}
 

pkg/reactor/reactor.go

@@ -148,7 +148,7 @@ func (r *Reactor) Run(ctx context.Context, manifest *api.Documentation, dryRun b
 	}()
 
 	if err := ResolveManifest(ctx, manifest, r.ResourceHandlers, r.manifestAbsPath, r.IndexFileNames); err != nil {
-		return err
+		return fmt.Errorf("failed to resolve manifest: %s. %+v", r.manifestAbsPath, err)
 	}
 
 	if err := checkForCollisions(manifest.Structure); err != nil {
@@ -190,7 +190,7 @@ func addSourceLocation(locations map[string][]*api.Node, node *api.Node) {
 func printResolved(ctx context.Context, manifest *api.Documentation, writer io.Writer) error {
 	s, err := api.Serialize(manifest)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to serialize the manifest. %+v", err)
 	}
 	writer.Write([]byte(s))
 	writer.Write([]byte("\n\n"))