1 files changed, 54 insertions, 0 deletions
diff --git a/packages/astro/src/frontend/render/utils.ts b/packages/astro/src/frontend/render/utils.ts
new file mode 100644
index 000000000..5d13ca136
--- /dev/null
+++ b/packages/astro/src/frontend/render/utils.ts
@@ -0,0 +1,54 @@
+import unified from 'unified';
+import parse from 'rehype-parse';
+import toH from 'hast-to-hyperscript';
+import { ComponentRenderer } from '../../@types/renderer';
+import moize from 'moize';
+// This prevents tree-shaking of render.
+Function.prototype(toH);
+
+/** @internal */
+function childrenToTree(children: string[]) {
+  return children.map((child) => (unified().use(parse, { fragment: true }).parse(child) as any).children.pop());
+}
+
+/**
+ * Converts an HTML fragment string into vnodes for rendering via provided framework
+ * @param h framework's `createElement` function
+ * @param children the HTML string children
+ */
+export const childrenToVnodes = moize.deep(function childrenToVnodes(h: any, children: string[]) {
+  const tree = childrenToTree(children);
+  const vnodes = tree.map((subtree) => {
+    if (subtree.type === 'text') return subtree.value;
+    return toH(h, subtree);
+  });
+  return vnodes;
+});
+
+/**
+ * Converts an HTML fragment string into h function calls as a string
+ * @param h framework's `createElement` function
+ * @param children the HTML string children
+ */
+export const childrenToH = moize.deep(function childrenToH(renderer: ComponentRenderer<any>, children: string[]): any {
+  if (!renderer.jsxPragma) return;
+  const tree = childrenToTree(children);
+  const innerH = (name: any, attrs: Record<string, any> | null = null, _children: string[] | null = null) => {
+    const vnode = renderer.jsxPragma?.(name, attrs, _children);
+    const childStr = _children ? `, [${_children.map((child) => serializeChild(child)).join(',')}]` : '';
+    /* fix(react): avoid hard-coding keys into the serialized tree */
+    if (attrs && attrs.key) attrs.key = undefined;
+    const __SERIALIZED = `${renderer.jsxPragmaName}("${name}", ${attrs ? JSON.stringify(attrs) : 'null'}${childStr})` as string;
+    return { ...vnode, __SERIALIZED };
+  };
+  const serializeChild = (child: unknown) => {
+    if (['string', 'number', 'boolean'].includes(typeof child)) return JSON.stringify(child);
+    if (child === null) return `null`;
+    if ((child as any).__SERIALIZED) return (child as any).__SERIALIZED;
+    return innerH(child).__SERIALIZED;
+  };
+  return tree.map((subtree) => {
+    if (subtree.type === 'text') return JSON.stringify(subtree.value);
+    return toH(innerH, subtree).__SERIALIZED
+  });
+});