tidy rewriting of imports

src/compiler/compile/create_module.ts

@@ -95,16 +95,16 @@ function esm(
 	// edit user imports
 	imports.forEach(node => {
 		const value = edit_source(node.source.value, sveltePath);
+		if (node.source.value !== value) {
 			node.source.value = value;
-		if (node.source.raw) {
-			node.source.raw = JSON.stringify(value);
+			node.source.raw = null;
 		}
 	});
 	exports_from.forEach(node => {
-		const value = edit_source(node.source!.value, sveltePath);
-		node.source!.value = value;
-		if (node.source?.raw) {
-			node.source.raw = JSON.stringify(value);
+		const value = edit_source(node.source.value, sveltePath);
+		if (node.source.value !== value) {
+			node.source.value = value;
+			node.source.raw = null;
 		}
 	});