fix(core): harden remaining nil-safe rendering paths

Co-Authored-By: Virgil <virgil@lethean.io>

node.go

@@ -60,6 +60,9 @@ func Raw(content string) Node {
 }
 
 func (n *rawNode) Render(_ *Context) string {
+	if n == nil {
+		return ""
+	}
 	return n.content
 }
 
@@ -103,6 +106,10 @@ func Attr(n Node, key, value string) Node {
 }
 
 func (n *elNode) Render(ctx *Context) string {
+	if n == nil {
+		return ""
+	}
+
 	b := newTextBuilder()
 
 	b.WriteByte('<')
@@ -126,6 +133,9 @@ func (n *elNode) Render(ctx *Context) string {
 	}
 
 	for i := range len(n.children) {
+		if n.children[i] == nil {
+			continue
+		}
 		b.WriteString(n.children[i].Render(ctx))
 	}
 
@@ -158,6 +168,9 @@ func Text(key string, args ...any) Node {
 }
 
 func (n *textNode) Render(ctx *Context) string {
+	if n == nil {
+		return ""
+	}
 	return escapeHTML(translateText(ctx, n.key, n.args...))
 }
 

pipeline.go

@@ -51,7 +51,10 @@ func Imprint(node Node, ctx *Context) reversal.GrammarImprint {
 	if ctx == nil {
 		ctx = NewContext()
 	}
-	rendered := node.Render(ctx)
+	rendered := ""
+	if node != nil {
+		rendered = node.Render(ctx)
+	}
 	text := StripTags(rendered)
 	tok := reversal.NewTokeniser()
 	tokens := tok.Tokenise(text)
@@ -65,6 +68,9 @@ func CompareVariants(r *Responsive, ctx *Context) map[string]float64 {
 	if ctx == nil {
 		ctx = NewContext()
 	}
+	if r == nil {
+		return make(map[string]float64)
+	}
 
 	type named struct {
 		name string
@@ -73,6 +79,9 @@ func CompareVariants(r *Responsive, ctx *Context) map[string]float64 {
 
 	var imprints []named
 	for _, v := range r.variants {
+		if v.layout == nil {
+			continue
+		}
 		imp := Imprint(v.layout, ctx)
 		imprints = append(imprints, named{name: v.name, imp: imp})
 	}