Use npm package names to load internal deps (#294)

* Use npm package names to load internal deps

This is necessary so that published Astro components work. These components will be built by esinstall and therefore they cannot rely on `_astro_internal`. The fix is to use npm specifiers everywhere.

* Move most of frontend to internal

* Mark astro/internal/markdown.js as external

* Move markdown stuff to its own package

This moves the markdown stuff to its own package so that we can externalize it in the markdown component.

* Add the changeset

1 files changed, 69 insertions, 0 deletions

diff --git a/packages/markdown-support/src/index.ts b/packages/markdown-support/src/index.ts
new file mode 100644
index 000000000..4db3089ba
--- /dev/null
+++ b/packages/markdown-support/src/index.ts
@@ -0,0 +1,69 @@
+import type { AstroMarkdownOptions } from './types';
+
+import createCollectHeaders from './rehype-collect-headers.js';
+import scopedStyles from './remark-scoped-styles.js';
+import { remarkCodeBlock, rehypeCodeBlock } from './codeblock.js';
+import raw from 'rehype-raw';
+
+import unified from 'unified';
+import markdown from 'remark-parse';
+import markdownToHtml from 'remark-rehype';
+// import smartypants from '@silvenon/remark-smartypants';
+import rehypeStringify from 'rehype-stringify';
+
+export interface MarkdownRenderingOptions extends Partial<AstroMarkdownOptions> {
+  $?: {
+    scopedClassName: string | null;
+  };
+  mode: 'md' | 'astro-md';
+}
+
+/** Internal utility for rendering a full markdown file and extracting Frontmatter data */
+export async function renderMarkdownWithFrontmatter(contents: string, opts?: MarkdownRenderingOptions | null) {
+  // Dynamic import to ensure that "gray-matter" isn't built by Snowpack
+  const { default: matter } = await import('gray-matter');
+  const { data: frontmatter, content } = matter(contents);
+  const value = await renderMarkdown(content, { ...opts, mode: 'md' });
+  return { ...value, frontmatter };
+}
+
+/** Shared utility for rendering markdown */
+export async function renderMarkdown(content: string, opts?: MarkdownRenderingOptions | null) {
+  const { $: { scopedClassName = null } = {}, mode = 'astro-md', footnotes: useFootnotes = true, gfm: useGfm = true } = opts ?? {};
+  const { headers, rehypeCollectHeaders } = createCollectHeaders();
+
+  let parser = unified().use(markdown).use(remarkCodeBlock());
+
+  if (scopedClassName) {
+    parser = parser.use(scopedStyles(scopedClassName));
+  }
+
+  if (useGfm) {
+    const { default: gfm } = await import('remark-gfm');
+    parser = parser.use(gfm);
+  }
+
+  if (useFootnotes) {
+    const { default: footnotes } = await import('remark-footnotes');
+    parser = parser.use(footnotes);
+  }
+
+  let result: string;
+  try {
+    const vfile = await parser
+      .use(markdownToHtml, { allowDangerousHtml: true, passThrough: ['raw'] })
+      .use(raw)
+      .use(rehypeCollectHeaders)
+      .use(rehypeCodeBlock())
+      .use(rehypeStringify)
+      .process(content);
+    result = vfile.contents.toString();
+  } catch (err) {
+    throw err;
+  }
+
+  return {
+    astro: { headers, source: content },
+    content: result.toString(),
+  };
+}
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