Skip private attributes incells serialization

internal/document/edit/cell.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"strconv"
+	"strings"
 
 	"github.com/stateful/runme/internal/document"
 	"github.com/yuin/goldmark/ast"
@@ -155,12 +156,16 @@ func serializeFencedCodeAttributes(w io.Writer, cell *Cell) {
 
 	_, _ = w.Write([]byte{' ', '{', ' '})
 
-	// Sort attributes by key, however, keep the element
-	// with the key "name" in front.
+	// Filter out private keys, i.e. starting with "_" or "runme.dev/".
 	keys := make([]string, 0, len(cell.Metadata))
 	for k := range cell.Metadata {
+		if strings.HasPrefix(k, "_") || strings.HasPrefix(k, "runme.dev/") {
+			continue
+		}
 		keys = append(keys, k)
 	}
+	// Sort attributes by key, however, keep the element
+	// with the key "name" in front.
 	slices.SortFunc(keys, func(a, b string) bool {
 		if a == "name" {
 			return true
@@ -176,7 +181,7 @@ func serializeFencedCodeAttributes(w io.Writer, cell *Cell) {
 		v := cell.Metadata[k]
 		_, _ = w.Write([]byte(fmt.Sprintf("%s=%v", k, v)))
 		i++
-		if i < len(cell.Metadata) {
+		if i < len(keys) {
 			_, _ = w.Write([]byte{' '})
 		}
 	}

internal/document/edit/cell_test.go

@@ -248,26 +248,40 @@ pre-commit install
 	)
 }
 
-func Test_serializeCells_unknownLang(t *testing.T) {
-	data := []byte(`## Non-Supported Languages
-
-` + "```py { readonly=true }" + `
-def hello():
-    print("Hello World")
-` + "```" + `
-`)
+func Test_serializeCells_attributes(t *testing.T) {
+	data := []byte("```sh { name=echo first= second=2 }\necho 1\n```\n")
 	doc := document.New(data, cmark.Render)
 	node, _, err := doc.Parse()
 	require.NoError(t, err)
 	cells := toCells(node, data)
 	assert.Equal(t, string(data), string(serializeCells(cells)))
 }
 
-func Test_serializeCells_attributes(t *testing.T) {
+func Test_serializeCells_privateFields(t *testing.T) {
 	data := []byte("```sh { name=echo first= second=2 }\necho 1\n```\n")
 	doc := document.New(data, cmark.Render)
 	node, _, err := doc.Parse()
 	require.NoError(t, err)
+
+	cells := toCells(node, data)
+	// Add private fields whcih will be filtered out durign serialization.
+	cells[0].Metadata["_private"] = "private"
+	cells[0].Metadata["runme.dev/internal"] = "internal"
+
+	assert.Equal(t, string(data), string(serializeCells(cells)))
+}
+
+func Test_serializeCells_unknownLang(t *testing.T) {
+	data := []byte(`## Non-Supported Languages
+
+` + "```py { readonly=true }" + `
+def hello():
+    print("Hello World")
+` + "```" + `
+`)
+	doc := document.New(data, cmark.Render)
+	node, _, err := doc.Parse()
+	require.NoError(t, err)
 	cells := toCells(node, data)
 	assert.Equal(t, string(data), string(serializeCells(cells)))
 }