optimize for static contenteditable value

src/compiler/compile/render_dom/wrappers/MustacheTag.ts

@@ -25,10 +25,14 @@ export default class MustacheTagWrapper extends Tag {
 			this.parent instanceof ElementWrapper &&
 			this.parent.attributes.filter((a) => a.node.is_spread);
 
-		let contenteditable_attr_value: Expression | undefined = undefined;
+		let contenteditable_attr_value: Expression | true | undefined = undefined;
 		if (contenteditable_attributes.length > 0) {
-			const value = (contenteditable_attributes[0] as AttributeWrapper).get_value(block);
+			const attribute = contenteditable_attributes[0] as AttributeWrapper;
-			contenteditable_attr_value = x`${value}`;
+			if ([true, 'true', ''].includes(attribute.node.get_static_value())) {
+				contenteditable_attr_value = true;
+			} else {
+				contenteditable_attr_value = x`${attribute.get_value(block)}`;
+			}
 		}	else if (spread_attributes.length > 0 && data.element_data_name) {
 			contenteditable_attr_value = x`${data.element_data_name}['contenteditable']`;
 		}
@@ -37,7 +41,11 @@ export default class MustacheTagWrapper extends Tag {
 			block,
 			value => {
 				if (contenteditable_attr_value) {
+					if (contenteditable_attr_value === true) {
+						return x`@set_data_contenteditable(${this.var}, ${value})`;
+					} else {
 						return x`@set_data_maybe_contenteditable(${this.var}, ${value}, ${contenteditable_attr_value})`;
+					}
 				} else {
 					return x`@set_data(${this.var}, ${value})`;
 				}

src/runtime/internal/dev.ts

@@ -91,12 +91,16 @@ export function set_data_dev(text: Text, data: unknown) {
 	text.data = (data as string);
 }
 
-export function set_data_maybe_contenteditable_dev(text: Text, data: unknown, attr_value: string) {
+export function set_data_contenteditable_dev(text: Text, data: unknown) {
-	if (~contenteditable_truthy_values.indexOf(attr_value)) {
 	data = '' + data;
 	if (text.wholeText === data) return;
 	dispatch_dev('SvelteDOMSetData', { node: text, data });
 	text.data = (data as string);
+}
+
+export function set_data_maybe_contenteditable_dev(text: Text, data: unknown, attr_value: string) {
+	if (~contenteditable_truthy_values.indexOf(attr_value)) {
+		set_data_contenteditable_dev(text, data);
 	} else {
 		set_data_dev(text, data);
 	}

src/runtime/internal/dom.ts

@@ -587,11 +587,15 @@ export function set_data(text: Text, data: unknown) {
 	text.data = (data as string);
 }
 
-export function set_data_maybe_contenteditable(text: Text, data: unknown, attr_value: string) {
+export function set_data_contenteditable(text: Text, data: unknown) {
-	if (~contenteditable_truthy_values.indexOf(attr_value)) {
 	data = '' + data;
 	if (text.wholeText === data) return;
 	text.data = (data as string);
+}
+
+export function set_data_maybe_contenteditable(text: Text, data: unknown, attr_value: string) {
+	if (~contenteditable_truthy_values.indexOf(attr_value)) {
+		set_data_contenteditable(text, data)
 	} else {
 		set_data(text, data);
 	}